Why Diet and Exercise Fail: How Current Research Contradicts Conventional Wisdom about Weight Loss
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Average customer review:Product Description
Why Diet and Exercise Fail demonstrates that traditional theories of weight gain cannot fully explain rising rates of obesity in the United States. Agricultural workers are among the most physically active people in California, yet they have one of the highest rates of obesity. The Inuit, or Eskimo, traditionally received 75% of their calories from fat and stayed lean, but eating a high fat diet did not produce weight loss in all the followers of the Atkins diet. In the 1950s, the rural Thai ate a diet with 80% of its calories from white rice, a refined carbohydrate, yet they remained thin. Low calorie diets have been tried since the beginning of the twentieth century to little effect. Over 99% of people who lose weight on low calorie diets return to their previous weight within three years. The problem with these diets is that they do not take into account how different types of food affect hunger levels. To see what could be influencing hunger, the book looks at obesity research that identifies factors which can cause weight gain. Soda consumption tends to predict weight gain, but diet soda consumption is an even stronger predictor of weight gain than is regular soda. Sleep deprivation predicts weight gain and is associated with increased hunger. In fact, people who are overweight tend to have higher levels of hunger than people of normal weight, despite the fact that they have already eaten too much. Increased hunger seems to be the mechanism by which prescription drugs and stress can lead to weight gain. However, hunger does not appear to explain why overweight people are less able to use stored fat and why food makes them feel less full, compared to people who are thin. The American diet underwent huge changes beginning in the twentieth century. Many of these have had profound nutritional implications of which we are not aware. Almost all of the bread products in the United States, including those labeled whole wheat, have had their grain oils removed. This extends their shelf life, but it radically alters their nutrient content. Caffeine, food additives, refined sugars, and chemical pesticides have a profound nutritional impact as well. In addition, the types of fats in the modern diet are different from those which we ate historically. Giving our livestock commercial feed made from corn and soy, instead of grass, has radically altered the types of fats we eat, as has consuming refined vegetable oils. Some of these changes in our diet can cause sleep deprivation, stress, increased hunger, and reduced use of stored fat. Although they are conventional wisdom, many common theories about nutrition are incorrect. While dietary fiber is believed to lower cholesterol and body weight, defatted fiber has no such effect. A nutrient stored in the fat in fiber appears to be responsible for fiber’s beneficial effects. Also, while omega-6 rich oils are supposed to be unhealthful and omega-3 rich oils healthful, this is not always the case. A highly anti-inflammatory oil rich in omega-6 is largely removed from the American diet during food processing. Its absence has probably contributed to increasing rates of chronic inflammatory diseases and insulin resistance. While healthful eating is supposed to be difficult, there are relatively easy changes to our diet that can have a profound impact on our weight and our health.
Product Details
- Amazon Sales Rank: #800193 in Books
- Published on: 2009-04-14
- Original language: English
- Number of items: 1
- Binding: Paperback
- 182 pages
Customer Reviews
An Interpretation of Weight-Gain Theories
This work surveys many different hypotheses for the massive increase in obesity in recent decades, not only in western countries but also in many other parts of the world. Korn surveys not only the usual culprits (fats, excessive calories, sedentary lifestyle, etc.), but also unusual ones (e. g., pollution, viruses). Some parts of his reasoning are more convincing than others.
Korn credits the successes of the Atkins diet not to restriction of carbohydrates, but to the quitting of coffee consumption. (p. 105). This may be correct in part, but cannot be the full answer. (I speak from experience. I lost 50 pounds on the Atkins Diet despite continuing to drink 2-3 cups of coffee a day). As a matter of fact, Atkins did not forbid moderate amounts of caffeine consumption, except in the short Induction phase. Atkins recommended that caffeine consumption be permanently discontinued only by those who get blood-sugar imbalances from it. (See, for instance, THE ATKINS DIABETES REVOLUTION, pp. 237-239).
Likewise, Atkins allows for some fruit-juice consumption (ibid, p. 144), and a tolerable moderate-weight-maintaining daily intake of carbs (ACE: Atkins Carbohydrate Equilibrium: ibid, pp. 129-130). Thus, such observations as fruit juices not necessarily causing obesity (Korn, p. 28), and Thais not being commonly obese despite eating mostly refined rice (Korn, pp. 26-27), are reconcilable with the premises of the Atkins diet.
Do low-carb diets often fail, in long term, because overconsumption of refined carbohydrates is not the cause of obesity? Or is it because, once the brain is trained to want an excess of carbs, it is quite difficult for many individuals to avoid drifting back to old ways of eating over the span of many years?
Nevertheless, Korn has performed a valuable service. The links between coffee, Omega6/Omega-3 imbalances, and obesity are fascinating, and clearly deserve further research.
Not a fully tested theory, but a very intriguing one
This is one of the most intriguing books I have read on nutrition. This is a very quick read. But, it is a page turner that will get your mental wheels spinning. It contains three separate parts.
In the first one, the author debunks all the existing merits of current diet fads. The Atkins diet followers proved that eating a diet rich in fat did not cause weight gain. However, they also proved that avoiding carbohydrates did not cause weight loss as their respective weights remained fairly stable. The author also documents that many foreigners including Eskimos and French among others eat far more fat than we do. Yet, they are lean. But, they gain weight upon moving to the U.S. and eating our more balanced diet. The same is true for Asians who eat a diet focused on simple carbohydrates with a high glycemic index (white rice). Many nutritionists suggest such a diet should cause weight gain. Asians are actually very lean and only gain weight upon moving to the U.S.
The second part explores the newer avenues related to weight gain potential causes. This includes our drinking increasing amount of sodas, our suffering rising case of sleep deprivation, our experiencing higher level of hunger for unexplained reasons. All those factors have documented impact on weight gain.
The third part is the big surprise: caffeine causes weight gain. The author develops a pretty rigorous logic that seems to make sense. It starts with our changing agricultural practices. We used to feed farm animals grass and hay. And, the fish we ate relied mainly on algae for their food. All those plants are rich in healthy Omega-3s essential fatty acids. So, by eating these animals our own diet was rich in Omega-3s. With the advent of agribusiness, our farm animals are fed corn and soy. And farm fishes are not fed algae anymore. As a result, our diet has become Omega-3s deficient. This has negative health implications including sleep deprivation. The latter causes us to drink more coffee in the morning as a stimulant. Coffee further causes sleep deprivation and increases stress level within our system measured by a higher level of cortisol. In turn, sleep deprivation and stress causes hunger. This specific hunger causes us to eat more than we need and gain weight. Sleeping problems and high level of cortisol have been observed among overweight people. So, this chain reaction turns into a permanent vicious feedback loop.
The above theory also explains the obesity pandemic among the youth. This is because of their huge rise in sodas intake. The author refers to a study that shows the higher intake of sodas the higher the probability of obesity. But, the probabilities were nearly 30% higher for diet soda (that have no calories!) vs regular sodas. What gives? Well, the majority of sodas have quite a bit of caffeine. But, diet sodas have 30% more caffeine, thus the higher probability of weight gain. The more caffeine kids intake the more they overeat.
Keep in mind the author theory has not been validated by scientific studies. The author does share that many studies found no relationship between coffee intake and weight. Yet, the author explains why. He uncovered that many individuals from Nordic European descent have a gene (altered A2a adenosine receptor) that protects them from the negative effect of coffee (sleeplessness, stress, hunger and weight gain). This gene is an evolutionary adaptation for living in northern climates with less sunlight and allowing for higher absorption of Vitamin D. As a result, such individuals turn out to be heavy coffee drinkers since they enjoy only the benefits (stimulation) without the negative side effects. When these individuals are not screened out, the resulting studies studying the impact of coffee on weight gains are automatically flawed. Even worse, some of them find a relationship between coffee and weight loss. This is why diet pills include coffee as an active ingredient. To further confuse cause and effect, the same northern Europeans have a diet much richer in Omega-3s than the American one as they eat more fish that is much richer in such fatty acids. Thus, they totally avoid the whole sleeplessness-hunger-weight gain chain reaction.
At this stage, the author has advanced valid arguments why flawed scientific studies have not confirmed his hypothesis that coffee does cause weight gain. However, this remains an untested hypothesis. A rigorous scientific study that does screen out for individuals who have the protective gene has yet to be done. Hopefully, the author's insight will lead to such a study. In the mean time, for any one with weight issues it does not cost you anything to give it a try and eliminate coffee intake and increase Omega-3s.
If you are intrigued by genetic variance implication in nutrition, I also recommend the excellent The Metabolic Typing Diet: Customize Your Diet to Your Own Unique Body Chemistry. Also, of interest is Eat Right 4 Your Type: The Individualized Diet Solution to Staying Healthy, Living Longer & Achieving Your Ideal Weight.
Plausible and thought-provoking new insights
The Enuit (Eskimos) have eaten a traditional diet extremely high in fat, yet remain lean - until they adopt a modern western diet. The rural Thai get eighty percent of their calories from refined white rice - yet it's the urban Thai who are gaining weight. Drinkers of diet soda are just as likely, if not more so, to gain weight as those who consume regular sugar-laden soda. Why?
In this fascinating book, author Daniel Matthew Korn examines both traditional and modern theories as to the reasons for weight gain in the modern era. Many of these theories seem to make good sense at first glance, but he illustrates in detail how, when examined closely, most do not hold up as complete explanations for our weight gain. This painstakingly researched book cites many specific studies as evidence, and Mr. Korn poses plausible new theories as to the possible causes of our obesity explosion.
Mr. Korn considers the link between sleep disturbance, caffeine and cortisol, the effects of stress on hunger, how the obese have higher levels of hunger, and how correlation is not necessarily cause when examining reasons for weight gain. Setting this book apart from others in its genre, he methodically debunks the fat-free craze, high-fat diets, low-carb diets, and sugar-free diets with both science and credible logic. He also notes how the types of fats we eat have changed, due to corn-fed animals (as opposed to grass-fed in the past and elsewhere in the world).
Mr. Korn's insightful conclusions absolutely merit closer examination and serious long-term studies. I have read a few studies that mentioned some of these observations, but I haven't read another book that pulled it all together like this. This book needs to be on the shelf of anyone struggling with weight. Highly recommended!





