Thursday, July 09, 2009
Can your Dentist help you lose weight?
ScienceDaily (July 9, 2009) — A scientific team from The Forsyth Institute has discovered new links between certain oral bacteria and obesity. In a recent study, the researchers demonstrated that the salivary bacterial composition of overweight women differs from non-overweight women. This preliminary work may provide clues to interactions between oral bacteria and the pathology of obesity. This research may help investigators learn new avenues for fighting the obesity epidemic.
This work will be published in the Journal of Dental Research."There has been a world-wide explosion of obesity, with many contributing factors," said Dr. J. Max Goodson, senior author of the study. "However, the inflammatory nature of the disease is also recognized. This led me to question potential unknown contributing causes of obesity. Could it be an epidemic involving an infectious agent?" "It is exciting to image the possibilities if oral bacteria are contributing to some types of obesity," added Goodson.
Summary of Study
In order to measure the salivary bacterial populations of overweight women, samples were collected from 313 women with a body mass index between 27 and 32 (classifying them as overweight). Using DNA analysis, the researchers measured the bacterial populations of this group and compared it with historical data from 232 individuals that were not overweight. Significant differences in seven of the 40 species studied occurred in the salivary bacteria of subjects in the overweight group.
In addition, more than 98 percent of the overweight women could be identified by the presence of a single bacterial species, called Selenomanas noxia, at levels greater than 1.05 percent of the total salivary bacteria. These data suggest that the composition of salivary bacteria changes in overweight women. It seems likely that these bacterial species could serve as indicators of a developing overweight condition and possibly be related to the underlying causation.
Dr. Goodson noted that the reasons for a relationship between obesity and oral bacteria are likely complex. The observed relationship may be circumstantial as being related to diet or opportunistic due to metabolic changes. In the next phase of this research, Dr. Goodson plans to further examine this relationship by initially conducting a controlled cohort study to see if this initial observation can be reproduced. In addition, he hopes to conduct longitudinal studies in children to see if oral infection relates to weight gain. Ultimately, the development of strategies to eliminate specific oral bacteria would be required to provide definitive evidence that certain oral bacteria may be responsible for weight gain.
J. Max Goodson, DDS, PhD, is a Senior Member of the Staff at The Forsyth Institute and heads up The Forsyth Clinical Research Collaborative (CRC). . Principal research personnel associated with the CRC include scientists that conduct clinical and health care delivery research.
This work was supported in part by Interleukin Genetics of Waltham, MA and by a grant from the National Institute of Dental and Craniofacial Research.
The Forsyth Institute is the world's leading independent organization dedicated to scientific research and education in oral health and related biomedical sciences.
- Goodson, J.M., Groppo, D., Halem, S., Carpino, E. Is Obesity an Oral Bacterial Disease? Journal of Dental Research, Online July 8, 2009 88: 519-523 DOI: 10.1177/0022034509338353
Labels: oral bacteria
Saturday, October 04, 2008
Half your intake to drop your weight
But the body isn't perfect. There's a delay of about 20 minutes between your gut and your brain, so you can eat way more than your body needs before feeling full. This trick and the next ones help avoid this.
Anytime you're hungry and about to eat, take half a serving. Keep the other half close: you can always eat it if the first wasn't enough. Eat the first half and wait 10 minutes, so your gut and brain get to talk. Then listen to your body. Still hungry? Go ahead, eat the other half. Not hungry? Keep it for later.
Congratulations, you've just cut your calories by 2 for that meal, and you're on your way to a fitter you.
ACTION STEP 15
Take half a serving of your next meal.
ACTION STEP 15 REVISITED
Apply this strategy for the rest of today and tomorrow. Notice how less you eat.
Monday, September 08, 2008
The Skinny on Epigenetics
Here's the wikipedia entry of epigenetics:
In biology, the term epigenetics refers to changes in gene expression. These changes may remain through cell divisions for the remainder of the cell's life. Sometimes the changes last for multiple generations. However, there is no change in the underlying DNA sequence of the organism, instead, environmental factors cause the organism's genes to behave (or "express themselves") differently. The best example of epigenetic changes in eukaryotic biology is the process of cellular differentiation. During morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo which in turn become fully differentiated cells. In other words, a single fertilized egg cell - the zygote - changes into the many cell types including neurons, muscle cells, epithelium, blood vessels et cetera as it continues to divide. It does so by a process of activating some genes while silencing others.
Etymology and definitions
The word epigenetics has had many definitions, and much of the confusion surrounding its usage relates to these definitions having changed over time. Initially it was used in a broader, less specific sense but it has become more narrowly linked to specific molecular phenomena occurring in organisms.
Epigenetics (as in "epigenetic landscape") was coined by C. H. Waddington in 1942 as a portmanteau of the words genetics and epigenesis. Epigenesis (see contrasting principle of preformationism) is an older word to describe the differentiation of cells from their initial totipotent state in embryonic development. When Waddington coined the term the physical nature of genes and their role in heredity was not known; he used it as a conceptual model of how genes might interact with their surroundings to produce a phenotype.
Robin Holliday defined epigenetics as "the study of the mechanisms of temporal and spatial control of gene activity during the development of complex organisms." Thus epigenetic can be used to describe any aspect other than DNA sequence that influences the development of an organism.
The modern usage of the word is more narrow, referring to heritable traits (over rounds of cell division and sometimes transgenerationally) that do not involve changes to the underlying DNA sequence. The Greek prefix epi- in epigenetics implies features that are "on top of" or "in addition to" genetics; thus epigenetic traits exist on top of or in addition to the traditional molecular basis for inheritance.
The similarity of the word to "genetics" has generated many parallel usages. The "epigenome" is a parallel to the word "genome," and refers to the overall epigenetic state of a cell. The phrase "genetic code" has also been adapted—the "epigenetic code" has been used to describe the set of epigenetic features that create different phenotypes in different cells. Taken to its extreme, the "epigenetic code" could represent the total state of the cell, with the position of each molecule accounted for; more typically, the term is used in reference to systematic efforts to measure specific, relevant forms of epigenetic information such as the histone code or DNA methylation patterns.
Molecular basis of epigenetics
The molecular basis of epigenetics is complex. It involves modifications of the activation of certain genes, but not the basic structure of DNA. Additionally, the chromatin proteins associated with DNA may be activated or silenced. What this means is that every cell in your body has the same instruction manual, but different cell types are using different chapters. Your neurons, for example, contain the DNA instructions on how to make your fingernails- but in neurons, those genes are turned off. Epigenetic changes are preserved when cells divide. Most epigenetic changes only occur within the course of one individual organism's lifetime, but some epigenetic changes are inherited from one generation to the next. Specific epigenetic processes include paramutation, bookmarking, imprinting, gene silencing, X chromosome inactivation, position effect, reprogramming, transvection, maternal effects, the progress of carcinogenesis, many effects of teratogens, regulation of histone modifications and heterochromatin, and technical limitations affecting parthenogenesis and cloning.
Epigenetic research uses a wide range of molecular biologic techniques to further our understanding of epigenetic phenomena, including chromatin immunoprecipitation (together with its large-scale variants ChIP-on-chip and ChIP-seq), fluorescent in situ hybridization, methylation-sensitive restriction enzymes, DNA adenine methyltransferase identification (DamID) and bisulfite sequencing. Furthermore, the use of bioinformatic methods is playing an increasing role (computational epigenetics).
Several types of epigenetic inheritance systems may play a role in what has become known as cell memory:
DNA methylation and chromatin remodeling
Because the phenotype of a cell or individual is affected by which of its genes are transcribed, heritable transcription states can give rise to epigenetic effects. There are several layers of regulation of gene expression. One way that genes are regulated is through the remodeling of chromatin. Chromatin is the complex of DNA and the histone proteins with which it associates. Histone proteins are little spheres that DNA wraps around. If the way that DNA is wrapped around the histones changes, gene expression can change as well. Chromatin remodeling is initiated by one of two things:
- The first way is post translational modification of the amino acids that make up histone proteins. Histone proteins are made up of long chains of amino acids. If you change the amino acids that are in the chain, you can change the shape of the histone sphere. DNA is not completely unwound during replication. It is possible, then, that the modified histones may be carried into each new copy of the DNA. Once there, these histones may act as templates, initiating the surrounding new histones to be shaped in the new way. By altering the shape of the histones around it, these modified histones would ensure that a differentiated cell would STAY differentiated, and not convert back into being a stem cell.
- The second way is the addition of methyl groups to the DNA, at CpG sites, to convert cytosine to 5-methylcytosine. Cytosine is the nucleotide that our cells can "read." Our cells cannot "read" methylcytosine. If you think of your DNA as an instruction manual again, changing cytosine to methylcytosine is like changing the font on your word document to "wingdings." Since the cell can no longer "read" the gene, the gene is turned off.
The way that the cells stay differentiated in the case of DNA methylation is more clear to us than it is in the case of histone shape. Basically, certain enzymes (such as Dnmt1) "prefer" the methylated cytosine. If this enzyme comes to a "hemimethylated" portion of DNA (DNA where only one strand contains the methylcytosine, and the other side still contains cytosine) the enzyme will methylate the other half.
Although modifications occur throughout the histone sequence, the unstructured termini of histones (called histone tails) are particularly highly modified. These modifications include acetylation, methylation and ubiquitylation. Acetylation is the most highly studied of these modifications. For example, acetylation of the K14 and K9 lysines of the tail of histone H3 by histone acetyltransferase enzymes (HATs) is generally correlated with transcriptional competence.
One mode of thinking is that this tendency of acetylation to be associated with "active" transcription is biophysical in nature. Because lysine normally has a positive charge on the nitrogen at its end, lysine can bind the negatively charged phosphates of the DNA backbone and prevent them from repelling each other. The acetylation event converts the positively charged amine group on the side chain into a neutral amide linkage. This removes the positive charge causing the DNA to repel itself. When this occurs, complexes like SWI/SNF and other transcriptional factors can bind to the DNA, thus opening it up and exposing it to enzymes like RNA polymerase so transcription of the gene can occur.
In addition, the positively charged tails of histone proteins from one nucleosome may interact with the histone proteins on a neighboring nucleosome, causing them to pack closely. Lysine acetylation may interfere with these interactions, causing the chromatin structure to open up.
Lysine acetylation may also act as a beacon to recruit other activating chromatin modifying enzymes (and basal transcription machinery as well). Indeed, the bromodomain—a protein segment (domain) that specifically binds acetyl-lysine—is found in many enzymes that help activate transcription including the SWI/SNF complex (on the protein polybromo). It may be that acetylation acts in this and the previous way to aid in transcriptional activation.
The idea that modifications act as docking modules for related factors is borne out by histone methylation as well. Methylation of lysine 9 of histone H3 has long been associated with constitutively transcriptionally silent chromatin (constitutive heterochromatin). It has been determined that a chromodomain (a domain that specifically binds methyl-lysine) in the transcriptionally repressive protein HP1 recruits HP1 to K9 methylated regions. One example that seems to refute the biophysical model for acetylation is that tri-methylation of histone H3 at lysine 4 is strongly associated with (and required for full) transcriptional activation. Tri-methylation in this case would introduce a fixed positive charge on the tail.
It should be emphasized that differing histone modifications are likely to function in differing ways; acetylation at one position is likely to function differently than acetylation at another position. Also, multiple modifications may occur at the same time, and these modifications may work together to change the behavior of the nucleosome. The idea that multiple dynamic modifications regulate gene transcription in a systematic and reproducible way is called the histone code.
DNA methylation frequently occurs in repeated sequences, and may help to suppress 'junk DNA': Because 5-methylcytosine is chemically very similar to thymidine, CpG sites are frequently mutated and become rare in the genome, except at CpG islands where they remain unmethylated. Epigenetic changes of this type thus have the potential to direct increased frequencies of permanent genetic mutation. DNA methylation patterns are known to be established and modified in response to environmental factors by a complex interplay of at least three independent DNA methyltransferases, DNMT1, DNMT3A and DNMT3B, the loss of any of which is lethal in mice. DNMT1 is the most abundant methyltransferase in somatic cells, localizes to replication foci, has a 10–40-fold preference for hemimethylated DNA and interacts with the proliferating cell nuclear antigen (PCNA). By preferentially modifying hemimethylated DNA, DNMT1 transfers patterns of methylation to a newly synthesized strand after DNA replication, and therefore is often referred to as the ‘maintenance' methyltransferase. DNMT1 is essential for proper embryonic development, imprinting and X-inactivation.
Chromosomal regions can adopt stable and heritable alternative states resulting in bistable gene expression without changes to the DNA sequence. Epigenetic control is often associated with alternative covalent modifications of histones. The stability and heritability of states of larger chromosomal regions are often thought to involve positive feedback where modified nucleosomes recruit enzymes that similarly modify nearby nucleosomes. A simplified stochastic model for this type of epigenetics is found here .
Because DNA methylation and chromatin remodeling play such a central role in many types of epigenic inheritance, the word "epigenetics" is sometimes used as a synonym for these processes. However, this can be misleading. Chromatin remodeling is not always inherited, and not all epigenetic inheritance involves chromatin remodeling.
It has been suggested that the histone code could be mediated by the effect of small RNAs. The recent discovery and characterization of a vast array of small (21- to 26-nt), non-coding RNAs suggests that there is an RNA component, possibly involved in epigenetic gene regulation. Small interfering RNAs can modulate transcriptional gene expression via epigenetic modulation of targeted promoters.
RNA transcripts and their encoded proteins
Sometimes a gene, after being turned on, transcribes a product that (either directly or indirectly) maintains the activity of that gene. For example, Hnf4 and MyoD enhance the transcription of many liver- and muscle-specific genes, respectively, including their own, through the transcription factor activity of the proteins they encode. Other epigenetic changes are mediated by the production of different splice forms of RNA, or by formation of double-stranded RNA (RNAi). Descendants of the cell in which the gene was turned on will inherit this activity, even if the original stimulus for gene-activation is no longer present. These genes are most often turned on or off by signal transduction, although in some systems where syncytia or gap junctions are important, RNA may spread directly to other cells or nuclei by diffusion. A large amount of RNA and protein is contributed to the zygote by the mother during oogenesis or via nurse cells, resulting in maternal effect phenotypes. A smaller quantity of sperm RNA is transmitted from the father, but there is recent evidence that this epigenetic information can lead to visible changes in several generations of offspring.
- For more details on this topic, see Prions.
Prions are infectious forms of proteins. Proteins generally fold into discrete units which perform distinct cellular functions, but some proteins are also capable of forming an infectious conformational state known as a prion. Although often viewed in the context of infectious disease, prions are more loosely defined by their ability to catalytically convert other native state versions of the same protein to an infectious conformational state. It is in this latter sense that they can be viewed as epigenetic agents capable of inducing a phenotypic change without a modification of the genome.
Fungal prions are considered epigenetic because the infectious phenotype caused by the prion can be inherited without modification of the genome. PSI+ and URE3, discovered in yeast in 1965 and 1971, are the two best studied of this type of prion. Prions can have a phenotypic effect through the sequestration of protein in aggregates, thereby reducing that protein's activity. In PSI+ cells, the loss of the Sup35 protein (which is involved in termination of translation) causes ribosomes to have a higher rate of read-through of stop codons, an effect which results in suppression of nonsense mutations in other genes. The ability of Sup35 to form prions may be a conserved trait. It could confer an adaptive advantage by giving cells the ability to switch into a PSI+ state and express dormant genetic features normally terminated by premature stop codon mutations.
Structural inheritance systems
- For more details on this topic, see Structural inheritance.
In ciliates such as Tetrahymena and Paramecium, genetically identical cells show heritable differences in the patterns of ciliary rows on their cell surface. Experimentally altered patterns can be transmitted to daughter cells. It seems existing structures act as templates for new structures. The mechanisms of such inheritance are unclear, but reasons exist to assume that multicellular organisms also use existing cell structures to assemble new ones.
Functions and consequences
Somatic epigenetic inheritance, particularly through DNA methylation and chromatin remodeling, is very important in the development of multicellular eukaryotic organisms. The genome sequence is static (with some notable exceptions), but cells differentiate in many different types, which perform different functions, and respond differently to the environment and intercellular signalling. Thus, as individuals develop, morphogens activate or silence genes in an epigenetically heritable fashion, giving cells a "memory". In mammals, most cells terminally differentiate, with only stem cells retaining the ability to differentiate into several cell types ("totipotency" and "multipotency"). In mammals, some stem cells continue producing new differentiated cells throughout life, but mammals are not able to respond to loss of some tissues, for example, the inability to regenerate limbs, which some other animals are capable of. Unlike animals, plant cells do not terminally differentiate, remaining totipotent with the ability to give rise to a new individual plant. While plants do utilise many of the same epigenetic mechanisms as animals, such as chromatin remodeling, it has been hypothesised that plant cells do not have "memories", resetting their gene expression patterns at each cell division using positional information from the environment and surrounding cells to determine their fate.
Epigenetics has many and varied potential medical applications. Congenital genetic disease is well understood, and it is also clear that epigenetics can play a role, for example, in the case of Angelman syndrome and Prader-Willi syndrome. These are normal genetic diseases caused by gene deletions, but are unusually common because individuals are essentially hemizygous because of genomic imprinting, and therefore a single gene knock out is sufficient to cause the disease, where most cases would require both copies to be knocked out.
Although epigenetics in multicellular organisms is generally thought to be a mechanism involved in differentiation, with epigenetic patterns "reset" when organisms reproduce, there have been some observations of transgenerational epigenetic inheritance (e.g., the phenomenon of paramutation observed in maize). Although most of these multigenerational epigenetic traits are gradually lost over several generations, the possibility remains that multigenerational epigenetics could be another aspect to evolution and adaptation. These effects may require enhancements to the standard conceptual framework of the modern evolutionary synthesis.
Epigenetic features may play a role in short-term adaptation of species by allowing for reversible phenotype variability. The modification of epigenetic features associated with a region of DNA allows organisms, on a multigenerational time scale, to switch between phenotypes that express and repress that particular gene. Whereas the DNA sequence of the region is not mutated, this change is reversible. It has also been speculated that organisms may take advantage of differential mutation rates associated with epigenetic features to control the mutation rates of particular genes.
Epigenetic changes have also been observed to occur in response to environmental exposure—for example, mice given some dietary supplements have epigenetic changes affecting expression of the agouti gene, which affects their fur color, weight, and propensity to develop cancer.
Epigenetic effects in humans
Genomic imprinting and related disorders
Some human disorders are associated with genomic imprinting, a phenomenon in mammals where the father and mother contribute different epigenetic patterns for specific genomic loci in their germ cells. The most well-known case of imprinting in human disorders is that of Angelman syndrome and Prader-Willi syndrome—both can be produced by the same genetic mutation, chromosome 15q partial deletion, and the particular syndrome that will develop depends on whether the mutation is inherited from the child's mother or from their father. This is due to the presence of genomic imprinting in the region. Beckwith-Wiedemann syndrome is also associated with genomic imprinting, often caused by abnormalities in maternal genomic imprinting of a region on chromosome 11.
Transgenerational epigenetic observations
Marcus Pembrey and colleagues also observed that the paternal (but not maternal) grandsons of Swedish boys who were exposed to famine in the 19th century were less likely to die of cardiovascular disease; if food was plentiful then diabetes mortality in the grandchildren increased, suggesting that this was a transgenerational epigenetic inheritance.
Cancer and developmental abnormalities
A variety of compounds are considered as epigenetic carcinogens—they result in an increased incidence of tumors, but they do not show mutagen activity (toxic compounds or pathogens that cause tumors incident to increased regeneration should also be excluded). Examples include diethylstilbestrol, arsenite, hexachlorobenzene, and nickel compounds.
Many teratogens exert specific effects on the fetus by epigenetic mechanisms. While epigenetic effects may preserve the effect of a teratogen such as diethylstilbestrol throughout the life of an affected child, the possibility of birth defects resulting from exposure of fathers or in second and succeeding generations of offspring has generally been rejected on theoretical grounds and for lack of evidence. However, a range of male-mediated abnormalities have been demonstrated, and more are likely to exist. FDA label information for Vidaza(tm), a formulation of 5-azacitidine (an unmethylatable analog of cytidine that causes hypomethylation when incorporated into DNA) states that "men should be advised not to father a child" while using the drug, citing evidence in treated male mice of reduced fertility, increased embryo loss, and abnormal embryo development. In rats, endocrine differences were observed in offspring of males exposed to morphine. In mice, second generation effects of diethylstilbesterol have been described occurring by epigenetic mechanisms.
Epigenetics in microorganisms
Bacteria make widespread use of postreplicative DNA methylation for the epigenetic control of DNA-protein interactions. Bacteria make use of DNA adenine methylation (rather than DNA cytosine methylation) as an epigenetic signal. DNA adenine methylation is important in bacteria virulence in organisms such as Escherichia coli, Salmonella, Vibrio, Yersinia, Haemophilus, and Brucella. In Alphaproteobacteria, methylation of adenine regulates the cell cycle and couples gene transcription to DNA replication. In Gammaproteobacteria, adenine methylation provides signals for DNA replication, chromosome segregation, mismatch repair, packaging of bacteriophage, transposase activity and regulation of gene expression.
The yeast prion PSI is generated by a conformational change of a translation termination factor, which is then inherited by daughter cells. This can provide a survival advantage under adverse conditions. This is an example of epigenetic regulation enabling unicellular organisms to respond rapidly to environmental stress. Prions can be viewed as epigenetic agents capable of inducing a phenotypic change without modification of the genome.
- Baldwinian evolution
- Barbara McClintock
- Evolutionary developmental psychology
- Histone code
- Molecular biology
- Somatic epitype
- Synthetic genetic array
- Weismann barrier
- Oskar Hertwig, 1849-1922. Biological problem of today: preformation or epigenesis? The basis of a theory of organic development. W. Heinemann: London, 1896.
- R. Jaenisch and A. Bird (2003) Epigenetic regulation of gene expression: how the genome integrates intrinsic and environmental signals. Nat. Genet. 33 (Suppl) 245-254.
- Joshua Lederberg,The Meaning of Epigenetics, The Scientist 15(18):6, Sep. 17, 2001.
- R. J. Sims III, K. Nishioka and D. Reinberg (2003) Histone lysine methylation: a signature for chromatin function. Trends Genet. 19, 629-637.
- Rupert Sheldrake, A New Biology, morphogenetic fields.
- B. D. Strahl and C. D. Allis (2000) The language of covalent histone modifications. Nature 403, 41-45.
- C.H. Waddington (1942), The epigenotype. Endeavour 1, 18–20.
- B. McClintock (1978) Mechanisms that Rapidly Reorganize the Genome. Stadler Symposium vol 10:25-48
- G.W. Grimes; K.J. Aufderheide; Cellular Aspects of Pattern Formation: the Problem of Assembly. Monographs in Developmental Biology, Vol. 22. Karger, Basel (1991)
- Eva Jablonka and Marion J. Lamb Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life The MIT Press (2005) ISBN 978-0262101073
- Article on The Philosophy of Molecular and Developmental Biology to appear in Blackwell’s Guide to Philosophy of Science,. P.K. Machamer and M. Silberstein (Eds).
- Epigenetics edited by C. David Allis, Thomas Jenuwein, Danny Reinberg, and Marie-Laure Caparros. Cold Spring Harbor Press, 2007.
- Evolution by Nicholas Barton, Derek Briggs, Jonathan Eisen, David Goldstein, and Nipam Patel. Cold Spring Harbor Press, 2007.
- Chromatin and Gene Regulation: Mechanisms in Epigenetics by Bryan Turner. Blackwell Publishing, 2002.
- Epigenetics edited by J. Tost. Caister Academic Press, 2008.
- RNA and the Regulation of Gene Expression: A Hidden Layer of Complexity edited by K. V. Morris. Caister Academic Press, 2008.
Friday, August 22, 2008
The role of BMP-7 in Obesity
The promise of turning a beer gut into a six-pack has been raised from two studies into the link between fat and muscle.
But they say only the body's 'good' fat which we are born with can be transformed, and not the 'bad' fat created by over-eating and not exercising enough.
In two related studies published today in the journal Nature, scientists identify the factors that regulate fat formation and, most important, control the type of fat.
Although we all wish we had a little less of it, fat is essential for managing our energy balance and helping to regulate body temperature.
But there are two distinct types of fat tissue: white 'bad' fat acts as an energy store whereas brown 'good' fat, which largely disappears by adulthood, also helps in burning calories to generate body heat, which is crucial to keep babies warm.
Now one team has shown how to promote the manufacture of "good" brown fat, so we can burn more calories, while a second team, also working nearby on the US east coast in Boston, has shown how brown fat and muscle are linked, suggesting ways to interconvert the two. Both offer a new strategy to fight flab.
In the first study, Dr Yu-Hua Tseng and her colleagues at the Joslin Diabetes Centre, Harvard Medical School, identified one factor - bone morphogenetic protein 7 (BMP7) - that promotes brown fat development, after using gene therapy to introduce the protein into mice.
"Obesity is occurring at epidemic rates," comments Dr Yu-Hua Tseng. "We hope this study can be translated into applications to help treat or prevent obesity," though she stresses that "diet and exercise are still the best approaches for weight reduction in the general population."
he new work opens up the way for drugs to mimic the effects of BMP-7 and "may provide hope to these individuals in losing weight and preventing the metabolic disorders associated with obesity," she said, referring to the well known link between type two diabetes and obesity.
In the second Nature study, Prof Bruce Spiegelman and colleagues at the Dana-Farber Cancer Institute, Boston, show that the two types of fat develop from distinct cell types in the early embryo. They found a factor, called PRDM16, that regulates the switch between muscle and fat.
Knocking out PRDM16 in brown fat cells can convert them into muscle cells and they say that finding drugs to do this "could be powerful" when it comes to fighting obesity.
The confirmation will spur ongoing research with Dr Patrick Seale in his laboratory, he said, to see if drugs that rev up PRDM16 in mice -- and potentially, in people -- could convert white fat into brown fat and thereby treat obesity.
Another strategy, he said, might be to transplant brown fat cells into an overweight person to turn on the calorie-burning process. "I think we now have very convincing evidence that PRDM16 can turn cells into brown fat cells, with the possibility of combating obesity,"
Intriguingly, the link between brown fat and muscle has been known for centuries.
In 1551, when the Swiss naturalist Konrad Gessner first described brown adipose tissue, he stated that on examination it struck him it was "neither fat, nor flesh [nec pinguitudo, nec caro] - but something in between".
The new work shows that brown fat is more flesh-like than previously suspected.
These cells are brown because they are rich in energy burning structures called mitochondria. The new work makes sense of earlier research findings, such as the discovery that many proteins found in brown fat cells are more similar to those found in muscle than in white fat.
Health Survey for England data revealed that in 2006, 38 per cent of adults in England were overweight and 24 per cent were classified as obese.
Another report, Foresight: Tackling Obesities: Future Choices published last year, predicts that if no action is taken, by 2050, 60 per cent of men and 50 per cent of women and 25 per cent of children will be obese.
Thursday, June 26, 2008
The Downer of High Weight
There's rather a sad part to being overweight that goes way beyond the mere fact that you're unable to get into your favorite outfit. Many people who are overweight, especially if they have found that they're unable to lose the pounds no matter what they do, tend to reach a point of acceptance. They stop trying, even to the point of making excuses for their appearance. Some will even go as far as to say that there's just more of them to love. If you've been there, you know who you are and what a lonely place it really is. Well, the first thing that somebody needs to do when attempting to lose weight is actual deal with the problem in a realistic way without burying their head in the sand and either pretending it will go away or that it doesn't matter. This article will focus on some of the main things you'll need to do psychologically in order to deal with actually taking off the pounds.
The first, and probably most important thing that you'll have to do is to accept that you're overweight and that you need to diet. Denial is not going to get you anywhere. You have to stare the problem right in the face and confront it head on. You have to have a positive attitude that you're going to lose the weight. Sometimes attitude is everything. So going in with that positive attitude will make things a heck of a lot easier.
The next thing you have to do is tune out the outside world, especially your friends. When you hit the restaurants with them and order your fruit salad and cottage cheese, they're going to make their comments about why you're dieting. They're going to make you feel like you're missing out on that cherry cheese cake. You'll need to learn how to not let those remarks get to you. More importantly, you can't allow yourself to feel cheated. Make a game of it if you have to. Dieting can actually be fun, especially when you're making progress, which brings us to our next point.
There are safe ways to lose weight and then there are not so safe ways. I'm not talking so much about particular diets but the speed in which you lose the weight. It has been determined that you should not lose more than one pound per week in order to lose weight safely. So when you are going on a diet, you have to learn patience. If you're 50 pounds overweight, you're not going to lose all that weight overnight. Don't even attempt to do it because it's not healthy. One of the biggest reasons why people don't lose weight is that they don't have patience with their diet.
These are primarily the main things that you have to keep in mind when going on a diet. If you can manage to keep a positive attitude, block out all negative influences and learn to have patience, you've already won a big battle as far as losing the weight that you want to get rid of.
In the next article of this series, we'll go over what some of your most common dieting options are.
See you then.
Karl Warren is the owner of 'Fight Your Flab... Fast' - a new site dedicated to helping you achieve your perfect body. If you are serious about losing weight, or you simply want to slim down a little, you should check out http://www.fightyourflabfast.com/blog now.
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Tuesday, June 24, 2008
Morale and Weight : Thoughts on Keep One Up and One Down
So you've been on a great diet and exercise program for some time now and it's getting to be kind of a drag. Being consistent is getting more difficult, but you know you what will happen if you stop. That fat will start building up again...and you definitely don't want that. What is the key to sticking in there?
Motivation is the key to sticking with your weight loss program. If you don't stay motivated to lose weight, life can just stop being fun and sooner or later, you will fail. Staying motivated is the key to enjoying your weight loss process and to sticking with it.
So how do you stay motivated? There are a lot of tricks to staying motivated, but here are five that I think can really keep you going.
Using Your Imagination To Keep Motivated
The imagination is a wonderful thing. If you use it for weight loss you will be able to peer into a very encouraging future...a future that will keep you so excited about staying on your weight loss program that you will never want to give up! Regularly peeking at the future will not allow you to give up.
This is how it works. Just take a little time each day (it doesn't take much time) to close your eyes and use your imagination to picture what you will look like a year from now if you stick with your weight loss program every single day. In your mind, look at:
- How you will look after losing that 50-100 pounds (or whatever your goal is).
Wow, look at you! How much slimmer you are. You look great and you are smiling from ear to ear. You stuck with your weight loss program, and it was so worth it!
- How will you feel?
You feel great. "What are those little knobby things down there? Hey, those are my toes. I can stand up straight and see my toes. And look Ma, I can touch them too." And all that energy I have because I am carrying so much less weight around!
- What will people say when they see the change?
"Wow, don't you look great. You lost some weight, didn't you?" (What they are really thinking is, "Man you lost a lot of weight, you used to be heavy, but look at you now!" But they are too polite to put it that way.) But that's okay; the "Wow!" is what counts.
- What will you be wearing and how will you look in those much-smaller sizes?
What fun! You're just loving buying those smaller sizes. And it's so-o-o much easier and fun to shop in a regular store...and so many choices now! Costs less too!
- How will you feel when you look in the mirror?
Hey, this is great! I don't wince when I look in the mirror any more. You're all smiles. And standing sideways... "not bad, not bad at all!"
What you will be seeing is you in the future...if you stick with your weight loss program! Try to do this little exercise each day and that should keep you well motivated.
For more weight loss tips, and information on weight loss programs, diets, quick weight loss, weight loss exercise, and more, go to my Slimmer You Weight Loss Tips web site at http://www.slimmer-you-weight-loss-tips.com
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Sunday, June 22, 2008
The Skinny: Cautions Weight Loss Supplments
Weight loss supplements, diet pills, weight loss formulas are all a multi-billion dollar industry in the U.S. alone. So many people are looking to diet pills or wonder drugs to help them lose weight in the fastest possible time without trying to change anything in their eating habits and lifestyle. People are just too busy to get any exercise and they are not too disciplined to curb their appetite and eat only the right amount of food to help them function normally. Many are saying that food addiction is becoming increasingly common to many Americans - we eat even if we are not hungry and just love food period.
This is the reason that most Americans are getting bigger and bigger over the years. There is an abundance of food everywhere you turn and the latest fad is serving up bigger and bigger portions as well. Think about all the upsize, super size, biggie size, etc, that many fast food restaurants offer to their customers. And people wonder how did they get this big and heavy and isn't there a way to lose weight, if not overnight, at least in a month? These wrong concepts are what make the diet supplements and other diet fads so popular; they feed on the people's insecurities and their impatience to lose the weight they have gained over the years.
Many diet supplements, weight loss supplements, herbal or otherwise, promise a miracle cure for those who are overweight. The advertising is just too good to pass and so convincing that many will try them without even considering if they are safe or not. They promise to help you lose weight and get the body of your dreams in a month's time, which is in reality not healthy to do since the healthy way of shedding weight is at most 3-5lbs. a week.
So if you are excessively heavy, it will take more than a month to get back in shape, and you need more than a supplement to achieve that. A total lifestyle change and healthy eating is needed if you are serious in seeing changes.
Weight loss supplements are sad to say not regulated as drugs, this means they are not fully tested for side effects. Many supplements were later found to be dangerous and some are related to deaths, and some were found to damage internal organs especially the heart. If you opt to take these then you should be aware that these wonder pills are not fully tested and you are making yourself available for these companies to experiment with.
Whatever side effects you may experience as well as others will then be documented and if there are too many reports of incidents for that particular supplement, it is then banned in the market. That is how it works with supplements, your safety is not guaranteed because they are classified as foods and not drugs, therefore not regulated.
If you are serious about getting back in shape, the best road to recovery remains the same. And active lifestyle (exercise, movement) and healthy diets are the best way to go. They are proven and weight loss is more permanent and lasting.
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Labels: diet pills
Friday, June 20, 2008
Five Things to Add To Your Weight Loss
Certainly, you've tried a lot diet pills, read a lot of rapid weight loss tips on e-books and manuals. And the only thing you've lost so far is money instead of fat!
The problem with most rapid weight loss tips and programs offer you results that are outstanding BUT they're anything but permanent. After achieving your ideal weight, you hit a plateau and start rolling back to your fatter self.
If you're sick and tired of that, then these practical and time-tested rapid weight loss tips will surely bring you GUARANTEED and LONG-TERM results.
You just better make sure you'll apply these rapid weight loss tips.
Rapid Weight Loss Tips No. 1
Drop the junks and eat small meals.
If ever you're going to see that body of yours perfectly fit and sculpted, you cannot continue your lifestyle of care-free eating habits.
You NEED to put a stop to eating A LOT of junk and you MUST reduce your diet by half. Here's an example: instead of eating your dinner in one serving, break down your meal into smaller ones and try to consume each of them after every 2-3 hours.
Another thing you can do to discourage yourself from eating too much is to buy plates that are way smaller in size than what you currently have.
Rapid Weight Loss Tips No. 2
I don't know about you BUT it has been scientifically proven that eating spicy foods aid greatly in rapid weight loss.
Now is the perfect time to love those hot and spicy foodstuffs you used to steer away from.
Rapid Weight Loss Tips No. 3
Go easy on meat. Sure they're protein rich that will aid greatly in building muscles and body mass. BUT they're also fat-dense!
Slowly but surely, decrease your meat consumption for the weeks to come and replace them instead with vegetables, soy proteins, mushrooms, etc.
Rapid Weight Loss Tips No. 4
Sweat it out! Go to the gym and workout everyday!
So you don't have the extra bucks to spend for the gym?
Walking a few miles to work and leaving your car at the parking area is just one of the nice things you can do to lose weight. Or instead of using the elevator, why not take the stair?
See, just look around you and you'll find more than a hundred ways to stay active and lose weight.
Rapid Weight Loss Tips No. 5
Now you may have some prescribed drugs for weight loss, BUT you sure want to replace them with herbal counter parts instead..
Aside from having minimal to totally ZERO side effects, there are other benefits you can grab from herbal supplements like Ayurslim which helps you lower you cholesterol levels and risk of heart-attack.
Steven is a long time health and fitness enthusiast and has been involved in diet, weight loss and exercise since 2002.
If you're looking for valuable and practical tips, tricks, and secrets about weight loss & fitness, so that you can loss weight naturally and rapidly to enjoy a healthier and happier life, do visit http://www.tipsforfastweightloss.com
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Wednesday, June 18, 2008
Dieting : A Sub-culture
Obesity is certainly a rapidly growing health crisis in the United States, and many corporations, media forums, and organizations are dedicated to fighting this nation-wide epidemic. Television shows such as "The Biggest Loser," "Shaq's Big Challenge," and "Fat March" have even turned weight loss into a public competition. Not only is the obese population of America on a mission to shed those pounds, but it seems as though most people, whether they are 5 pounds or 50 pounds overweight, are eager to slim down, tone up, and achieve the body of their dreams. Americans spend over 4 billion dollars a year on diet pills, appetite suppressants, and fat diet plans. Over time, this diet craze has created a new increasingly popular subculture in America: diet culture.
WHY IS DIETING SO POPULAR?
The market is flooded with images of perfectly sculpted bodies, airbrushed figures, and flawless features. From magazine ads to cosmetics packaging, Americans are constantly told by the media that perfection is obtainable. In addition, increasing health threats aided by obesity puts more pressure on Americans to lose weight and avoid these health threats. A combination of these pressures forces people to spend hundreds of dollars on quick-fix diets to lose weight and improve their health as quickly as possible with minimal effort.
It seems as though there are hundreds, if not thousands, of diet pills on the market. Every diet pill claims to be the best and claims that you can effortlessly shed the pounds once and for all. Every diet pill works differently, but there are four main types of diet pills on the market: those that suppress appetite with an amphetamine-like effect, a second type of appetite suppressant which triggers your brain to desire to eat less, a third which prevents the absorption of fats into your body, and fourth are detox pills which aid in digestion and food processing. Many diet pills can be extremely unsafe and hazardous to your health, and always require research before purchasing. So how do you know which diet pill to choose? Always look at a full list of ingredients and research any unfamiliar products in the pill. Also, don't be fooled by 'all natural' diet pills - just because the pill is made from all natural products does not necessarily mean it's completely safe. Always consult a physician before purchasing a new diet pill, and always ask for him or her for recommendations. If the product sounds too good to be true, it most likely is.
Much like diet pills, fad diets are everywhere. From Atkins to the Grapefruit Diet, fad diets have covered an entire spectrum of weight management. Everyone wants a diet that is easy and doesn't interfere with their daily lives, but also they want one that works. Too often do people start a fad diet and end up gaining back the weight that they lost, if not more, after stopping the diet plan. So how do you choose the right diet for you? Sometimes, simply watching your calorie intake and increasing your activity can prove effective. If that doesn't work, look for diets that allow you to eat foods that are nutrient-rich and lean. Diets that make you starve yourself are never a good idea, and most of those diets are the ones that will cause you to gain excess weight back after you stop the diet.
Jim Mackey is a renowned dietitian. He has been advising people on how to maintain a proper diet and how to lose those extra calories. If you want to know more about Diet, south beach diet, diet plans, diabetic diet you can visit www.dietsinreview.com
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Monday, June 16, 2008
Losing More Than Weight : Hair Loss And Crash Diets
Hair loss is a problem that can be experienced by both men and women of all ages. One of the main reasons for hair loss is that it was inherited. Basically, your genes will determine whether you are prone to hair loss or not. Aside from this, there are many more causes of hair loss like bad habits, harmful hair treatments, skin infections, and even hormones.
Another important fact that you should know about hair loss is that diet can also make a huge impact in your hair's health. Although it is not known by many, crash dieting can actually lead to hair loss.
Crashing Diets Means Crashing Your Health
It is unfortunate but true, crash dieting has been proven to cause hair loss if prolonged for a long period of time. For this reason, everyone should be careful and eat the right diet. Deciding to succumb to crash diet (maybe due to an important event you would want to look your best for), might make your body react drastically because of the sudden threat caused by crash dieting. The result would be that the body will roughly store nutrients instead of using it to produce hair, which can lead to the dreaded hair loss. This can prove to be a bigger problem in the long run. Also diets that lack protein are especially risky because protein is a major component in healthy hair growth.
Body's Defense Against Crash Diet Malnutrition
Also note that the body would suddenly make all the vitamins and minerals in its system turn into maintaining your vital organs because it is deprived from the nutrients necessary for everyday living. During crash dieting therefore, it would stop all the mechanism necessary for maintaining your hair's health as it will devote all of its resources into preserving your life because of the threat of starvation.
Hair Phased Out Because of Crash Dieting
The hair has two phases. One is the growing phase and the other is the resting phase. Normally, almost ninety percent of your hair is in the growing phase while the remaining ten percent is in the resting phase. The ten percent that is in the resting phase is that hair that will start to fall. This is a part of its normal cycle so it is typical for you to lose some hair every once in awhile. However, in crash dieting, an unhealthy amount of hair that is in the growing phase would suddenly shift into the next phase, the resting phase. Hair is pushed into the resting phase by the body so that it can conserve all the nutrients it can. When this occurs, hair loss will follow.
In many cases, hair loss from crash dieting may not be experienced immediately. In fact, this is the reason people do not associate the hair loss they are experiencing to the crash dieting they did some months before. Usually, there are two to three months interval before the obvious consequence of the crash diet can be felt. This is in part because the hair that was in the resting phase previously would fall out as part of its cycle.
A person will most likely experience six months of hair loss due to crash dieting. And the hair would only return to its normal condition when you resume your normal eating habits. But there is still an added hazard because the stress that your body feels from starvation also has the possibility of producing a particular male hormone that is responsible for the destruction of the hair follicles. When this had already occurred, then the hair will no longer be able to grow because the follicles are gone. When this happens aside from cosmetic surgery that is available at astronomical prices, not much of remedy can be offered. Crash dieting is a great risk for people who already have the gene that is prone for baldness because the effects of crash dieting can be worse for them compared to other people
Charlene J. Nuble
For All the things you need to know about hair loss, please go to: Cause of Hair Loss
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Saturday, June 14, 2008
Vitamins and Weight Loss
When the human body is spending more energy in work and heat than it gains from food or other nutritional supplements it will catabolize stored reserves of fat and muscle. In other words, weight loss can only take place when the calories intake is less than the calories burn. Ones weight will stay the same when the calories one eats and drinks equal the calories one burns and add when the calories one eats and drinks are greater than the calories one burns.There are several essential nutrients missing from the diets most people eat. Replacing them with vitamin supplements doesn't make up for the synergistic effects of nutrients found in food.
Fiber is the indigestible part of vegetables, fruits, and whole grains. Whole grains and cereal fiber can lower your heart disease risk by 30%. To increase the fiber in your diet to the recommended 14g for every 1,000 calories eaten, have a 1/2 cup serving of Fiber One cereal and add more beans to your diet with lentil soup. Use whole grain bread and add some fruit and vegetables to your meals.
2)Magnesium and Potassium :
Magnesium and potassium are linked to blood pressure control, protection from osteoporosis, heart disease, diabetes and stroke. To add magnesium, have a half-cup of bran and cooked spinach daily. For potassium, eat sweet potatoes, white potatoes, white beans and bananas.
Calcium provides the raw material for building your teeth and bones. It prevents bone-thinning osteoporosis, contributes to healthy blood pressure, and can reduce the risk of colon cancer. To have the right amount in your diet, drink three glasses of low-fat or fat-free milk every day, or have eight ounces of fat-free yoghurt and 2-3 ounces of low-fat cheese each day.
Vitamin A cares for and maintains our eyes, the linings of the respiratory, intestinal and urinary tracts, and the quality of our skin. To add more vitamin A to your diet, add darkly-pigmented foods to your daily diet. These include carrots, spinach, kale, winter squash, and a medium baked sweet potato. They do not include lettuce and french fries.
Vitamin C is necessary for our body to create collagen, a glue that holds our skin, bones, blood vessels and skin together. It also helps to make brain chemicals, neutralize damaging free radicals, and metabolize cholesterol. Vitamin C may also help the heart and reduce arthritis and diabetes. To add vitamin C to your diet, simply add a glass of orange juice or an orange every day. Other helpful foods with vitamin C are kiwifruit, cantaloupe, Brussels sprouts, strawberries, red or green bell peppers, and broccoli.
6)Vitamin E :
Sufficient vitamin E also neutralizes free radicals to protect cells from damage, plays a role in the immune system, can help prevent the common cold, and can lower the risk of Parkinson's disease. Foods healthy in vitamin E include almonds, sunflower kernels, and sunflower oil in salad dressings, which helps you gain the nutrients from the vegetables and carry the vitamin E into the bloodstream.
The one thing that is key to consider: find these vitamins in your diet. Vitamins in pill form will often pass through the body. Vitamins found in your foods will always be incorporated in your body in a healthy way.
For more great site reviews and tips on weight loss visit these sites
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Thursday, June 12, 2008
Under The Knife : Thoughts on Weight Loss Thru Surgery
Perhaps you've tried dieting and failed. Atkins, South Beach, or even a nutritionist. And perhaps you've tried an exercise regimen and either had trouble sticking to it, or difficulties performing the exercises. If you're wondering if weight loss surgery, such as lap band surgery, is the best option for you at this point, the answer is... well... complicated.
It's important to realize that weight loss surgery is NOT cosmetic surgery. It is major surgery, it is potentially life threatening, and those that choose this route will have to make changes that will stay with them for the rest of their lives. Before reading on, please keep these facts in mind-- because weight loss surgery is not a decision to be made lightly. There are consequences to this choice, and not all of them are feel-good, positive consequences.
However, a lot of positive changes come from losing a large amount of weight, especially for a person who has faced lifelong struggles with their weight. An increase in mobility and enjoyment of time spent in active pursuits. Higher self-esteem and better self-image. These are all valuable changes, and are of course things you want in your life. But they should not be the only deciding factor in getting weight loss surgery. The most important reason --in fact, the only real reason-- for a person to get weight loss surgery is to live a better life, a healthier life, for longer. If those things are your true motivation for weight loss surgery, you may be a good candidate.
When looking online into your weight loss options, you've probably come across a lot of information about weight loss surgery. A lot of the information you'll find (especially on the web) comes from sources that you cannot necessarily trust. Don't take what you read at face value. The best thing to do when considering weight loss surgery is to talk to your doctor. He may refer you to a qualified surgeon who performs lap band or other weight loss surgeries, or you may need to find one on your own.
A qualified surgeon will be able to sit down with you, and outline the risks and benefits of the surgery. He should give you an indication of whether or not you're a good candidate for the surgery, and give you an overview of the process, including the life changes you'll need to make after the surgery itself. A lot of weight loss clinics offer seminars or information sessions about weight loss surgery. If you really think that weight loss surgery might be the right choice for you, you may want to think about attending. You'll meet people who are going through (or have been through) the same experiences and it's a good way to get support as well as information.
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Tuesday, June 10, 2008
30 Lbs in 20 Weeks
Losing weight seems to be a losing battle for so many people because they are either doing it all the wrong way, or they just don't stick at it.
Many weight loss programs are lacking in good information and once your "diet" is finished, you end up putting on on what you lost (and then some!), sending you right back to square one. This is extremely frustrating for so many people. It is little wonder there are so many overweight people in the world. Does any of this sound like you?
Now, what if you were to read a story of a woman who lost 30 pounds in only 20 weeks, who felt great, didn't have to exercise for hours at a time and who didn't have to starve herself to get there?
Well that's what I did this morning. I was reading through yet another Fit Yummy Mummy (FYM) success story of a 38 year old woman who had lost 30 pounds in 20 weeks. She had tried other weight loss programs before but none of them had worked. Until now.
Another funny thing about the FYM program is that many women (like myself) have to remind ourselves when to eat because we're not left hungry all day like many diets.
The FYM program is all about eating often and eating healthy. This is the most important aspect of losing weight in a healthy way. Also, exercise is a must, with a maximum of 90 minutes a week of your time required. This can be broken down into various combinations, such as 15 minutes a day, 6 days a week, or even 30 minutes a day, 3 days a week.
The FYM program is the best I've seen so far and it is so flexible that there really is no excuse for not sticking to it. You will learn exactly what you need to do to lose weight, once and for all!
If you really want to lose weight, then here's what you must do right now...
Visit http://overweightandunhappy.com and make sure you take advantage of the free offers available, including the free weight loss ecourse or you can check out Michelle's progress as she attempts to become a Yummy Mummy!
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Labels: 30 lbs
Sunday, June 08, 2008
Thoughts on the Popular Fad Diets
When was the last time you were tempted to try that fad diet you have found in the latest magazine that promises the world with fantastic fat losses and without doing a thing. What was it again; just take a couple of fat burning pills follow the diet and then bang! A brand new you in a couple of weeks.
The sad fact is they do not work, they just provide more suffering in your efforts to lose weight, and the only thing that you are losing is your hard earned money.
Firstly lets look at the latest fad diets on the scene at the moment, their pros and cons and then you will be shown how to save your time, money and unnecessary suffering by pointing you in the right direction for permanent weight loss.
The latest studies show that 90 per cent of fad dieters regained everything they had lost and even gained more weight within eighteen months.
The Atkins Diet.
The body burns carbohydrates and then fat for energy. This diet recommends limiting the intake of starchy, high carb foods so that the fat is burned first. So by eating meat, cheese and eggs and keeping bread and potatoes to a minimum, fat is lost.
Pros: Steak with cheese topping, Chocolate mocha ice cream and pork scratchings.
Cons: Studies show high protein diets lead to increased risk of heart disease, colon cancer, bad breath (halitosis) and constipation. Consuming more carbohydrate that can be used by the body will store this excess in fat cells.
The Zone Diet.
This diet claims to decrease hunger and boost energy by keeping your bodies eating habits in the zone or at its peak. Keeping all your meals and snacks in the ratio of 40% carbohydrates, 30% protein, and 30% fats does this.
Pros: Being a low calorie diet, you can't help but lose weight.
Cons: Very difficult to adhere to the strict regime the diet requires. Will experience metabolism slow down because of low calories and will lead to starvation response, which will eat away at the muscle tissue while retaining the fat.
The Blood Group Diet.
By having a blood test and determining your blood group, this then tells you how you can absorb nutrients, thus you can plan your diet accordingly. Different blood groups can eat different food groups.
Pros: Another calorie restricting diet so weight will be lost.
Cons: There appears to be little clinical and scientific evidence behind this diet and by the elimination of whole food group's important nutritional deficiencies are likely with long-term health problems encountered.
The Ashram Diet.
This diet is basically a very low calorie diet (near starvation), which is coupled with a very high intensity exercise regime. A sample of this diet would include: One boiled egg for breakfast, a green salad for lunch and a baked potato with salsa for dinner.
Pros: A very quick weight loss, 10 - 15 lbs in a week (Mostly muscle tissue and water).
Cons: Fast weight loss leads to many unpleasant side effects such as bad breath, bone loss, constipation, deprivation of nutrients (vitamins and minerals), muscle loss, metabolism slow down, headaches and poor sleep.
Who would want all these problems for the sake of quick weight loss where the weight will eventually be put back on and more in a couple of months?
The Hay Diet.
The main rule to follow for this diet is to not eat protein and carbohydrates together. Combination of these two foods together appears to prevent protein from being digested in the gut and can lead to an accumulation of toxins.
Vegetables and fruit form the bulk of the diet with very small portions of protein and carbs.
Pros: Plenty of fruit and veggies in the diet means plenty of vitamins, minerals and antioxidants.
Cons: There doesn't appear to be too much scientific evidence about food combinations and by limiting yourself to certain food groups you will miss out on important nutrients.
All these diets work because of a drastic cut in calories, when this happens our metabolic rate can be brought down in a matter of 36 hours by as much as 50% which means your body is now burning only half of your calories.
To compound matters further, hunger kicks in after a period of inadequate eating setting you up for over eating and binging.
Everyone is an individual so you have to be careful of diets that require you to set out what types of foods and quantities you have to eat at every meal. Just because a movie star lost weight on a fad diet doesn't mean that you will.
Before starting a weight loss program take into account your age, fitness levels, activity levels and medical history.
Do yourself a favour and follow a real weight loss program including all the food groups, strength training, low level aerobics, a slight decrease in your daily calorie levels and a program that can be followed for life.
Gary Matthews is the author of the popular fitness eBooks Maximum Weight Loss and Maximum Weight Gain. Please visit http://www.maximumfitness.com right now for your 'free' weight loss or muscle building e-courses.
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