Beyond Celiac: Study Sheds New Light on Obesogenic Effects of Gluten - Are PPARs & Bacteria Both Involved?

Cornflakes peanut butter cookies - guaranteed not gluten free ;-)

With Christmas Eve being over, and grandma's cookies, Christmas stollen, and all sorts of other stuff from the bakery in front of you (literally), Christmas Day may actually prove to be a way more "dangerous" than Christmas Eve - not just because of the total amount of calories, but also because of the low satiety effect of these sweet treats.

A recent paper by scientists from the Universidade Federal de Minas Gerais in Belo Horizonte in Brazil does now point to another reason you better give those bakery products a wide berth - not just, but especially with the energy overshoot on Christmas day: Gluten!

Study confirms for the first time what scientists and laymen alike have been speculating about

In what the scientists claim is the first well-controlled study of the effects of gluten intake on metabolic health in a non-celiac, but Western-style diet scenario, Fabíola Lacerda Pires Soares and her colleagues put two groups of C57BL/6 mice on identical, iso-caloric high fat (hypercaloric) diets that differed only in terms of the amount of gluten that was added to the chow (0% gluten vs. 4.5% gluten).

Interestingly, the gluten diet did not influence any of the usual suspects, like food intake, total fat-free mass, fecal lipids excretion, blood lipid profile, blood total protein and ectopic (liver and muscle) lipid concentration (if you look closely you will realize that the gluten-free group actually had higher TRIGs, although the difference did not reach statistical significance).

Figure 1: Usual suspects and closer look at the effects 8 weeks gluten supplemented vs. gluten-free diets had on serum markers of metabolic syndrome and visceral fat parameters (Soares. 2013)

The data in figure 1 (right) does yet also show that the gluten content of the diet did nevertheless have a significant impact on the total body mass, visceral fat mass, lipid content and most importantly the adipocyte size.

Figure 2: Absolute adipokine levels (left) and fasting glucose and insulin levels, as well as Homa-IR (Soares. 2013)

Add to that the blunted expression of the anti-inflammatory and anti-diabetic fat hormone adiponectin and the increased the >5x higher expression of leptin (figure 2). And mix that with the reduced expression of PPAR-alpha and gamma of which Soares et al. argue that they may well be the key factor in the detrimental modulatory effect the addition of gluten had on the visceral fat structure and the lowered expression of the fat liberating enzymes LPL and and HSL, as well as reduced levels of the fat burning proteins ACC and CPT-1 (figure 3).

Figure 3: PPAR-alpha, -gamma, LPL, HSL, ACC and CPT-1 expression compared to rodents on regular chow (left); crown like structures in stained slices from visceral fat, inflammatory markers TNF-alpha and IL-6 (Soares. 2013)

So, even if the initially mentioned blood markers (aka the usual suspects) would suggest that both the gluten-consuming and gluten-free rodents were similarly bad off, the profound difference in inflammatory markers within the adipose tissue and the presence of comparatively many necrotic and inflammatory adipocytes in the crown like structures stand in line with increases in HOMA-IR, fasting glucose and insulin and an already compromised glucose clearance which are well-known harbingers of the metabolic syndrome.

These observations do not simply shed a whole new light on a hitherto largely ignored contributer to the etiology of the metabolic syndrome, they do also show that one of the reasons it has not been identified before is an over-reliance on BMI, total fat mass and serum lipids in the early stages of diabesity.

Reardless of whether the gut microbiome is part of the mechanism by which gluten predisposes the development of metabolic syndrome. Eating more inulin- and beta-glucan rich foods like Jerusalem artichokes, agave, bananas, onion, steel cut oats, wild yams, yacon, etc. certainly won't hurt your efforts to get lean, stay lean and leave the role of the obese diabetic to the other (read more)

Bottom line: The study at hand provides a good reason to limit your intake of "healthy whole grains" and other gluten containing foods, regardless of whether you suffer from celiac or not. Whether the established detrimental effects of gluten on the integrity of the intestinal wall and the increased leakage of bacterially produced endotoxins from the highly unfavorably changes in the gut microbiome in response to the high fat diets (Hildebrandt. 2009) are part of, or even the primary cause of these observations still has to be elucidated. The same goes for strategies to counter the translocation of the endotoxins across the gut lining (cf. "Shedding some light on the leaky gut") and the dose response relationship between the total amount of gluten in your diet and its effects on your metabolism. With 7% of pure gluten, it goes without saying that you would basically have to live of wheat in order to get to anywhere similar amounts of gluten in the diet... that said: Is it possible that the effects occur only in the presence of the high fat diet? After all, this alone has been shown to favor a pro-inflammatory gut microbiome.

You see there are enough questions to be answered in 2013 and the SuppVersity is going to be the place you will read the respective answers first ;-)

References:

• Hildebrandt MA, Hoffmann C, Sherrill-Mix SA, Keilbaugh SA, Hamady M, Chen YY, Knight R, Ahima RS, Bushman F, Wu GD. High-fat diet determines the composition of the murine gut microbiome independently of obesity. Gastroenterology. 2009 Nov;137(5):1716-24.e1-2.
• Soares FL, de Oliveira Matoso R, Teixeira LG, Menezes Z, Pereira SS, Alves AC, Batista NV, de Faria AM, Cara DC, Ferreira AV, Alvarez-Leite JI. Gluten-free diet reduces adiposity, inflammation and insulin resistance associated with the induction of PPAR-alpha and PPAR-gamma expression. J Nutr Biochem. 2013 Dec 17.

Fat Loss Principles That Work: 10g+ of EAAs W/ Every Meal. Do Energetic Costs of Protein Synthesis Trigger This Effect?

EAAs beyond whey: It may not necessarily look like this, but this salad (repicecorner) is an EAA power horse with cheddar cheese (25% protein, 0.49 EAA / P ratio), tuna (in oil, 29%,  0.45) and kidney beans (9%, 0.45). You see, it does not always have to be chicken breasts or whey to get beyond the 10g+ EAA threshold, I have repeatedly suggested as one of the fundamental rules of dieting for weight loss, maintenance and muscle gain.

Many people take it for granted that you become fat, when you get old. If you look at the statistics, you could even make a point that obesity has some protective effects with esp. with respect to CVD mortality. Scientists call this the "obesity paradox" (Kastorini. 2013). What's particularly paradox, at least in my humble opinion, is yet not the phenomenon itself, but rather the fact that it gets smart scientists derailed from working on useful dietary and exercise interventions to prevent the development of heart disease, cancer, metabolic syndrome etc. in early years. Instead, they argue ex-post, i.e. when the baby has already been thrown out with the bathtub by comparing sick lean (in parts even cachectic) and sick "obese" people, why their statistical shenanigan that's based on the useless BMI produces paradoxical results. And that, when studies such as the one Jacobs et al. did in 2010 clearly show that 50+ year old men and women with waist circumference >120cm and >110cm, respectively, have 2x higher all-cause mortality risk than their lean peers - irrespective of BMI (Jacobs. 2010)!

To get lean and stay lean, yet not thin and skinny fat is therefore a challenge everyone...

... from the child in the Kindergarten to the obese granny in the nursing home is facing. Against that background a previous study by Loenneke et al. comes to mind. The results of their analysis, which were published in Nutrition and Metabolism in January 2013 clearly show that the amount of times people eat meals with a 10g+ EAA content per day was inversely related to percent central abdominal fat (Loenneke. 2013). In previous studies EAAs have also been shown to improve glucose clearance without increases in insulin and in the absence of effects on the fat burnin and health promoting expresion of AMPK-alpha2 in skeletal muscle tissue (see "EAAs Stimulate Muscle Glucose Uptake by Exponentiating Insulin's Effect on GLUT4 Expression"). With the advanced publication of a study by Coker, Miller, Schutzler, Deutz and Wolfe in the online verison of the Nutrition Journal a couple of days ago, the notion that EAAs have a particularly beneficial effect on fat loss - in this case in obese elderly individuals - gets further support from a well-controlled randomized trial (Cooker. 2013).

EAA-rich protein increases fat loss to a greater extent than low EAA protein

The researchers from the Center for Translational Research in Aging and Longevity and the University of Arkansas for Medical Sciences in Little Rock, AR, USA randomized 12 elderly individuals (mean age 69 years) to an 8 week, caloric restriction diet utilizing equivalent caloric meal replacements (~850 kcal/day; the exact nutrient composition can be found in figure 1) + ~400kcal from solid foods (total intake: ~1,250kcal/day; the subjects were free to chose their solid meals but were provided with a list of examples the should pick from, if possible).

Figure 1: Macronutrient composition of the meal replacements used in the study (Cooker. 2013)

The diet was designed to induce a 7% weight loss in two months. And while both,  the rate of weight loss (~1.6lbs per week), as well as the relatively high caloric deficit are certainly appropriate for someone with a 30+ BMI and ~40% body fat, leaner people will fare better with a less pronounced kcal deficit or (alternatively) have to add some strategically planned refeeds to the equation in order to minimize the loss of lean mass and, more importantly, avoid the ensuing reduction in energy expenditure (for the obese, the latter is actually less of the problem, because the downsides of being calorically deprived are at least partly counglucose tolerance and leptin sensitivity with every gram of body can actually help the body recognize that there is still plenty of energy that has just not been available (glucose) or "visible" (fat) before).

Figure 2: Changes in lean and fat mass (kg, left) and fractional protein synthesis rates (FSR) in participants receiving iso-caloric meal replacements with identical macronutrient compositions (see figure 1), but different amounts of essential amino acids (EAAs) content (Coker. 2013)

As the data in figure 2 goes to show you even the obese individuals in the study at hand lost a non-negligible amount of lean mass - unfortunately the body composition was measure with a sophisticated, but still body impedance based device, the trends are still accurate, but it is questionable in how much we are actually talking about ~2 and 2.5kg of muscle mass (figure 2, left), because somebody's "lean body mass" does obviously include more than just skeletal muscle.

When it comes to supplements, we are often like children on Christmas eve. About all the new stuff we get we tend to forget our former favorite and often way more fun to play with toys. Don't make this mistake and ditch your PWO whey (personally, I like a ~1.5:1 whey + micellar casein mixture) for EAAs, they don't come close... read more

Be that as it may - since the before and after values were taken with the same device the changes should be correct, so that both the slightly yet not statistically significantly ameliorated loss of lean body mass and, more importantly, the significantly higher degree of body fat loss in the EAA meal replacement (EAAMR) group speak in favor of the 5 servings of a the 170 kcal, 6g EAA per day. Moreover, "the sparing influence of muscle loss might have been demonstrated with a larger sample size", so that you can take it for granted that the preservation of precious muscle mass is an advantage of being choosy with your protein sources and preferring those with higher over those with lower essential amino acid contents.

On a related note: I don't know if you noticed, but with a total energy content of 850kcal and 30g EAA these 5 meal replacements did in fact have exactly those 10g+ of essential amino acids, I have repeatedly recommended to have with each of the 3 meals most people consume in the course of the day.

In all fairness, it should also be mentioned that despite not being significantly different at baseline, the body fat percentage of the subjects in the EAA meal replacement group was ~3% higher to begin with.This may seem irrelevant, since figure 2 compares lean mass and fat mass as absolute changes and not their percentages, but in the end, the amount of fat you you can drop within a given time-frame decreases with lower body fat percentages.

Do the energetic costs of protein synthesis drive fat loss?

Another interesting observation Coker et al. made is the close association between fat loss, on the one hand, and increased protein synthesis (55%), on the other hand. The researchers take this as an incentive to do one of the of the much loved calories in vs. calories out calculation and come up with the following hypothesis:

"Acute administration of EAAMR did promote a significant increase in skeletal muscle protein FSR compared to CMR. Assuming that the energy cost of protein synthesis is 3.6 kJ/g and the baseline GAIA-derived lean tissue mass was 56.4 kg for EAAMR and 54.4 kg for the CMR, we can extrapolate that the overall energy discrepancy between the two groups was roughly equivalent to 27,170 kcal or 3.5 kg of weight loss across the entire caloric restriction-based weight loss paradigm. Based on the amount of total lean mass in each group, this value takes into account a consistent intervention structure of five servings/day across an eight week period. In short, these calculations suggest that differences in the source of intact protein/formulation of EAA may have a significant influence on diet-induced energy expenditure that coincides closely with the greater reduction of adipose tissue in EAAMR compared to CMR." (my emphasis in Coker. 2013)

I usually discard fallacious calculations like this one if they are not highlight the stupidity of trying to eat exactly as much as some funky formula + the figure on your treadmill, pedometer, heart rate monitor or whatever fancy tool you may use to "measure" your energy expenditure suggest you would have burned in the last 24h. In this case, however, I made an exception, because I feel that the notion that protein quality is one of the myriad of parameters that are missing from this foolish calculation is important, for lean and obese people from all age groups who are trying to shed body fat.

Bottom line: The take away message of the study is in the end identical to the previously mentioned study by Loenneke et al.: Make sure you hit the 10g EAA threshold with each and every of your meals, if being lean and muscular not skinny yet fat is your goal.

References:

• Coker RH, Miller S, Schutlzer S, Deutz N, Wolfe RR. Whey protein and essential amino acids promote the reduction of adipose tissue and increased muscle protein synthesis during caloric restriction-induced weight loss in elderly, obese individuals. Nutr J. 2013 Dec 11;11(1):105. [Epub ahead of print]
• Jacobs EJ, Newton CC, Wang Y, Patel AV, McCullough ML, Campbell PT, Thun MJ, Gapstur SM. Waist circumference and all-cause mortality in a large US cohort. Arch Intern Med. 2010 Aug 9;170(15):1293-301.
• Kastorini CM, Panagiotakos DB. The obesity paradox: methodological considerations based on epidemiological and clinical evidence--new insights. Maturitas. 2013 Jul;72(3):220-4.
• Loenneke JP, Wilson JM, Manninen AH, Wray ME, Barnes JT, Pujol TJ. Quality protein intake is inversely related with abdominal fat. Nutr Metab (Lond). 2013 Jan 27;9(1):5.

What's Worse: YoYo-Dieting or Constant Gluttony? What Happens During Weight Cycling? And Why Does Every Diet Make You Fatter? Lots of Questions, a Couple of Answers

Image 1: To eat or to diet, what's worse?

Despite the fact that the magazines are still full of "X pounds in Y weeks" diets, more and more people begin to realize that "diet hopping" and even "dieting" in the conventional sense, i.e. following a special, usually very strict and non-sustainable nutritional regimen for a very short amount of time, are futile. But can calling a halt before you blow up like a balloon from time to time actually be worse than letting yourself go all-day, everyday? According to the results of an experiment that has been conducted at the Institute of Biology of the State University of Rio de Janeiro, the results of which have just been published in the open access journal PLoSOne, the answer to this question must be: YES, it can! And that may be true, even when you are not starving yourself!

Even "healthy" weight cycling turns out to be profoundly unhealthy!

Now, the unfortunate news first: We are, as so often dealing with a rodent study - one that was done conducted with 80(!) 3-months old C57BL/6 mice. "Wow! 80 mice? That's plenty!" Yeah, initially it may sound like that, but in view of the fact that their number was decimated every 8 weeks, there would not have been the necessary 4x8 rodents left at the end of the 24-week study period for the final evaluation of the four experimental groups, which were

• standard chow (SC; 15kJ/g) - rodents in this group received the standard chow (76% energy from carbohydrates, 14% energy from protein, and 10% energy from fats) for the whole study period
• high fat diet (HF; 21kJ/g) - rodents in this group received a fattening hypercaloric diet (26% energy from carbohydrates, 14% energy from protein, 50% energy from animal lard and 10% energy from soy bean oil 
• SC ↔ HF - rodents in this group received standard chow for the first 8-week cycle, high fat diet for the 2nd 8-week cycle and standard chow for the third and last 8-week cycle
• HF ↔ SC - rodents in this group received high fat diet for the first 8-week cycle, standard chow for the 2nd 8-week cycle and high fat  for the third and last 8-week cycle 

If we go back to the initial question, the HF group would be our 24/7, 365 days a year eat everything the worst Western diet you can imagine has to offer, while the animals in the group SC ↔ HF and HF ↔ SC group would be representative of

• the high school football player who turns to a sedentary lifestyle and bad eating habits when he goes to college, is partying all night, bear pizza, etc. eventually, he realizes he got fat, and diets again (SC ↔ HF ↔ SC) and
• the obese kid who eventually turns to physical culture, works out, eats health and loses weight, when he starts college, to then fall back into his old bad habits and starts letting himself go, when he marries and has kids (HF ↔ SC ↔ HF)

I know this is a little far-fetched and as we are going to see later, mice are not exactly the best model to study things like that, but still, the way the weight of the rodents, who had free access to the respective chow they were on during the whole experimental period, developed is quite telling:

Figure 1: Despite intermediate fat loss the increased feed efficiency (=weight gain per kcal) that is especially pronounced in the HF phases of the weight cycling groups quashed the previous weight loss. If age effects had not become a problem this effect would have been more obvious in a 4th cycle.

And the message the data in figure 1 is sending is quite clear: Dieting, as in changing your eating habits only intermediately, is useless, at best! - "at best", because it becomes increasingly difficult to lose and constantly easier to gain weight or, as Barbosa-da-Silva et al. put it:

[...] after three consecutive WC [weight cycles], the reduction of BM is less marked during the SC cycle, as well as the increase of BM is more prominent during HF cycle (Barbosa-da-Silva. 2013).

Now, we probably would not have had to do a 24-week rodent study to know that, right? Right! Notwithstanding, though, the beauty of working with rodents - instead of Biggest Losers, for example - is that they usually don't complain much when you slaughter them, so that the scientist could not only measure the serum leptin (figure 2, left), triglycerides, cholesterol, insulin and glucose levels, but also count the number and measure the size of the adipocytes in their visceral fat pads.

Figure 2: Leptin expression and adipocyte density per area of adipose tissue mass after the 1st, 2nd and 3rd weight gain/loss cycle (data adapted from Barbosa-da-Silva. 2013)

And as you can see in figure 2 (right) the weight cycling induced quite profound effects on the adipose tissue morphology; effects that are similar to what we have seen in previous discussions on the underlying causes of the yoyo effect (see "Nasty Insights into the YoYo-Effect"). You have to keep in mind, though, that you would be comparing apples and oranges if you compare the two weight cycling groups with each other, as one group has always just lost weight, when the other has gained weight so that in one group the adipocytes will  be depleted, when they are filled to the seams in the other one. If there had been a fourth cycle in the course of which the fat cells of the SC ↔ HF group would have been repleted, we may thus safely assume that the absolute size-differences, which reached statistical significance only in the HF ↔ SC group after the third cycle (violette bar in figure 2, right), would have been similar or even more pronounced after 32 weeks and 4 cycles in the then HF dieting SC ↔ HF (note: one of the reasons the researchers did extend the experiment for another 4 weeks was that even now, age-related effects and obesity related morbidities would have reduced the significance of the data).

Adipocyte morphology, leptin expression, fat pad restructuring and body fat that sticks

Apropos significance, you ay remember from the "previously mentioned post" on this issue that one of the currently discussed hypothesis that could  (at least partly) explain why formerly obese people are not just having a really hard time to lose weight, but also, and often even more so, to keep that weight off, relates to what I have previously labeled "relative leptin defiency" (too little leptin production per adipose tissue mass) or, and this would be an alternative hypothesis, "leptin resistance" (more than enough leptin in the blood, but the signal transmission does not work).

The first thing we can say based on the data Barbosa-da-Silva acquired on the absolute fluctuations of leptin in the blood of the rodents (figure 2, left) ist that previously made conclusions about the effects of weight gain, weight loss and energy intake on leptin, like

1. weight loss and fasting are associated with reduced leptin levels, 
2. weight gain is associated with an increase in leptin concentration 
3. chronically increased leptin can lead to leptin resistance
4. meals and according to meal composition or short-term swings in energy balance such as fasting or overfeeding induce swings in systemic leptin levels

appear to be accurate. To check whether there is evidence for my "relative leptin deficiency" hypothesis, especially in weight cycling groups, I ploted the ratio of serum leptin to body fat in figure 3 (left):

Figure 3: Leptin levels in serum per body fat (left), leptin expression in adipose tissue (middle), and sectional area of adipocytes of the different groups (based on Barbosa-da-Silva. 2013)

And what is interesting is that in this calorically non-restricted scenario, the respective "relative leptin deficiency" occurs only in the SC ↔ HF group during the third and last cycle, when their relative leptin levels which should actually be identical to the SC group (we must compare them to the SC group, because the current diet will influence leptin expression as well) are 36% lower than they "should" be. In the same third cycle, the HF ↔ SC group (remember, those are our "formerly obese kids") have 21% more leptin in their blood than they "should" - given their current adipose tissue mass.

Some food for thought - Though not directly related to the topic, there is one thing pertaining to the heavily debated "CLA post" from last week (cf. "CLA Destroys Body Fat"), I want to mention. If we assume that the CLA-induced adipose tissue apoptosis Kim et al. observed in their recent study is as rodent-specific as the natural death and rejuvenation of adipose tissue Cinti et al. observed in the study I cite relating to the limited adipose tissue growth in rodents, this would not just indicate that taking copious amounts of CLA would not help to reverse the damage you may have done during previous "diets", but could also explain why conjugated linoleic acid supplements don't work in humans (or horses; see yesterday's news).

Now this segues directly into the allegedly somewhat counter-intuitive conclusion that anything that soothes the raging inflammation in your fat cells may ameliorate the downstream detrimental effects on glucose and lipid metabolism, but will, on the other hand, help your fat cells to survive or maybe even proliferate in amidst the TNF-alpha induced cytokine storm (Prins. 1997), which would otherwise kill them. Now with the current paradigm of "inflammation = bad" this may sound hilarious. In the the end, it does yet only echo the title of a 1999 paper by Hube and Hauner, "The role of TNF-alpha in human adipose tissue:  Prevention of weight gain at the expense of insulin resistance?" (Hube. 1999) and would provide us with a mechanistic explanation of several otherwise non-explicable phenomena such as the profound fat loss in rodents who lack the master antioxidant glutathion (see "Inflammation Is the True Fat Burner"),,, but as indicated: This is just some food for thought ;-)

In combination with the leptin overshoot (+153%) in the "former football players on their college binge", this data would suggest that we are not dealing with "relative deficiency" and "leptin resistance" but rather with a complex mixture of both, where the latter is probably a result of repeated overshoots like the one we see in the SC ↔ HF group after their first high fat feeding cycle (2nd cycle, 154% elevated leptin levels).

Relative leptin deficiency, systemic resistance and now local differences?

And as if things were nor already complicated enough, there are also potentially important differences between circulating leptin levels and local leptin expression in isolated fat pads figure 3 (middle; compare data to figure 2, left, 3rd cycle). Thus, the drop in leptin levels upon "fasting" in the (SC ↔ HF, 2nd cycle  and HF ↔ SC, 3nd cycle) is systemic, but does not reflect the expression of leptin in the intra-abdominal tissue. This stands in line with my previous dissertation on "relative leptin deficiency" and the differences between...

• intra-abdominal (easy to shed on a diet), and 
• subcutaneous (esp. in the lower body compartment difficult to shed on a diet)

...adipose tissue in "Nasty Insights into the YoYo-Effect" (a similar depot-specificity has been reported for pre-adipocytes, i.e. developing fat cells, as well - intriguingly only in 9 out of human subjects (=81%); cf. Niesler. 1998). Due to the fact that the expansion of adipose tissue in rodents appears to be limited and the cell-turnover high (contrary to humans, where you get the impression that obesity is only limited by death and the cell-turnover - if it exists at all - must be very slow), these effects are probably even more pronounced in humans than in mice. Consequently, it can be expected that the diet / feasting induced upward shifts of the body fat set point are more pronounced and their morphological reversal either more time-consuming (probably true for the visceral body fat) than in rodents or simply impossible (could be the case for parts of the subcutaneous body fat) in human beings.

Image 1 : Lose 20lbs now, gain 25 back and have 5 stick with every diet! We still don't understand exactly why, but by now it should be clear, diets like the "Kendra diet" are rather part of the problem than viable solutions

Implications: Despite the fact that we still don't really understand what's happening, when we are trying to shed the body fat we have acquired in times of gluttony, the few novel insights we have gained from the study at hand should make it even more obvious that "classic" dieting does not hold the answer to the obesity problem. Neither on an individual, nor on a societal level. Instead of "eat less, exercise more", the main message should read: "Don't ever think of dieting, again! Revamp your life, your activity profile and the way you eat and wait for things to fall in place." After all, the "formerly obese kids" in the HF ↔ SC group were not too bad off, when they had returned to a (for rodents!) healthy diet in the 2nd cycle. We may even speculate that the difference the rodents in the control group (SC) would not have been significant anymore, if the scientists had kept the HF ↔ SC rodents on standard chow for another 8 weeks.

The same group is however living (now dead ;-) proof that the notion that you could diet today, look better tomorrow and then return to what has gotten you into misery before is not just illusive, but outright life-threatening. Since caloric restrictions, which are still at the heart of 99% of the mainstream diets, will probably magnify the amplitude (i.e. the up and down) of the yoyo effect and its negative metabolic consequences, it appears reasonable to assume that the yoyo-dieter will eventually be worse off than the "happy fatso" who has been eating whatever he wanted for all his life and dropped dead morbidly obese with a heart attack at 45. After all, it seems likely that he (or she!) will not even live to the 45th year before he falls victim to the very same fate and that after not despite, but rather because of all the temporary austerities... now, this may be like choosing between pest and cholera, and the third option, i.e. following the path of physical culture would alway be my first choice, but honestly, if I had to choose, I'd rather be the fatso who enjoyed his 45 years of pizza, pasta and chocolate pie than the frustrated yoyo dieter.

References

• Barbosa-da-Silva S, Fraulob-Aquino JC, Lopes JR, Mandarim-de-Lacerda CA, Aguila MB. Weight Cycling Enhances Adipose Tissue Inflammatory Responses in Male Mice. PLoS ONE 2013; 7(7): e39837.
• Cinti S, Mitchell G, Barbatelli G, Murano I, Ceresi E. Adipocyte death defines macrophage localization and function in adipose tissue of obese mice and humans. J Lipid Res 2005; 46: 2347–2355.
• Hube F, Hauner H. The role of TNF-alpha in human adipose tissue: prevention of weight gain at the expense of insulin resistance? Horm Metab Res. 1999 Dec;31(12):626-31.
• Kim JH, Kim J, Park Y. trans-10,cis-12 Conjugated Linoleic Acid Enhances Endurance Capacity by Increasing Fatty Acid Oxidation and Reducing Glycogen Utilization in Mice. Lipids. 2013 Jul 11.
• Niesler CU, Siddle K, Prins JB. Human preadipocytes display a depot-specific susceptibility to apoptosis. Diabetes. 1998 Aug;47(8):1365-8.  
• Prins JB, Niesler CU, Winterford CM, Bright NA, Siddle K, O'Rahilly S, Walker NI, Cameron DP. Tumor necrosis factor-alpha induces apoptosis of human adipose cells. Diabetes. 1997 Dec;46(12):1939-44.
• Zhu. Ncb5or in Fatty Acid Desaturation and Metabolic Diseases. Zhu Diabetes Research Group. University of Kansas School of Health Professionals. < http://www.alliedhealth.kumc.edu/school/research/zhu/more_info.html > retrieved July 22, 2013