Book Review of "Why We Get Fat and What to Do

Why We Get Fat And What to Do About It. Gary Taubes. New York: Alfred A. Knopf. 2011. 288pp.

Introduction
Gary Taube’s 2010-released book “Why We Get Fat and What to Do About It” (hereinafter to be referred as “why we get fat”) is well known for its paradigm-challenging explanation of causes of obesity against the energy-balance dynamics. Born in New York, Taubes is a science journalist with an interdisciplinary background in applied physics, aerospace engineering and journalism at high-profile institutions. Taubes joined Discover magazine as a staff reporter since 1982 and later his investigation interests shifted from physics to public health. “Why we get fat” is an “airplane reading version” of Taubes’ work “Good Calories, Bad Calories” in which he first elaborated the fattening impacts of high-carbohydrate food in 500-plus pages. Taubes expected this condensed “Why we get fat” to reach a wider range of audience and serve as a daily-life guidance upon readers’ critical review .

What Taubes Revealed
Taubes exerted great efforts to validate that weight loss is more complex than achieving a calorie deficit. Instead, “you are eating more because you are getting fat”. Insulin is one kind of hormones that is secreted to balance blood sugar in human body. It controls how calorie we eat will be processed. The higher insulin, the higher proportion of calorie will be transformed into fat, which stay in our fat cells. As fat is accumulated, fat cells develop resistance against insulin. A vicious cycle can thus be formed with levels of fat cells and insulin released increasing competitively. Some people tend to gain weight because they have insatiable cells due to hereditary factor or growth needs. The sugars, in particular-sucrose and high fructose corn syrup (HFCS) are key food that makes the difference here.

Reflection
In general, Taubes clearly illustrated the mechanism of carbohydrate consumption and fat accumulation, which is very convincing. However, what he argued didn’t disapprove the calorie-in/out system as he intended to. The next step should be discovering the synergy of the two perspectives since both sides have supportive evidence and criticism of study design that left the findings in doubt.

Let’s start with three reasons why Taubes’ work merits due credits. First, this book identified that carbohydrate is one of (despite the author tended to put it as “only”) the dietary trigger of the obesity and diabetes epidemics and explained the abstract physiology mechanism in a lucid manner. Taubes was not alone by arguing this. Over the past 30 years in the US, the percentage of calories from fat in people’s diets has gone down but obesity rates have skyrocketed . American Journal of Clinical Nutrition also links foods containing HFCS to obesity . A BBC documentary by BBC called “Sugar vs. Fat” exactly demonstrated a stronger fattening effect of consuming high-carbohydrate compared to calorie itself . Second, the book shed renewed lights on many neglected studies on obesity prevalence in the 20th century, which successfully reminded the readers of the depth and width of obesity studies. Third, Taubes explicitly spoke against attaching any moral judgments to obese people. Again, they “overeat because they are getting fat”.

My main criticism is that Taubes’ condescending attitude and exclusive mindset shown in this book. Though he cited a number of one-sided studies discounting the efficacy of energy balance paradigm, he did not properly consider compelling counterarguments. While an impressive number of subjects including physics, physiology, anthropology, and medical science are involved, nutrition and relevant findings are marginalized in this book. Successful examples of loosing weight by reducing calorie intake in reality show like The Biggest Loser were simply ignored.

The nutrition impact and optimal amount of protein and fat consumption was not deliberated when Taubes abstracted his dietary advice as “eating less carbohydrate” and challenged the conventional diet pyramid. Such overturn may be appealing to readers who seek evidence to justify their high-calorie and tasty diets but sufficient life experiences have told us this is not the whole story. As a Chinese, I consumed little amount of sucrose and HFCS in my daily diets as Taubes recognized in his book. However, my BMI rose up from 22.3 to 25.3 due to an overdue high-calorie food intake and extremely sedentary lifestyle during the whole year of preparing university entrance exam. Today, my diet is more westernized considering the increased proportion of juice drink, coffee and cheesecakes in my regular diets. However, my BMI has gone down to 21.0 due to regularized eating routine, reduced consumption of meat for dinner, and less deskbound lifestyle. A quick glimpse of the readers’ responses to Taubes can tell us well that the food effects of loosing weight are not as straightforward as Taubes dictated and calorie control does have worked for many people.

Meanwhile, Taubes left some grey areas behind, manifesting the adequacy of scrutinizing different hypotheses rather than unequivocally advocating one or the other. Questions that were not addressed in this book include:

• Can we isolate the fattening effects of calorie and carbohydrate?
Readers were presented with laboratory study results in which diets that were either calorie or carbohydrate restricted. Many food species such as nuts and some fruit species are both calorie- and carbohydrate- intensive. All the research Taubes cited disregard this important characteristic and weakened the validity of the fattening results on carbohydrate or calorie alone. On the other, if carbohydrate stimulates insulin that transforms calorie into fat as Taube argued, it may not be perfectly reasonable to divorce their functioning and impacts on fat accumulation. In fact, to promote low-calorie diet seems more sensible as it will reduce the calorie base of fat conversion. In fact, Taubes has co-created an NGO, Nutrition Science Initiative , highlighting the necessity of conducting more specifically controlled studies and studying the competing assumptions.
                                   
• Is obesity reversible if Taube is right?
In Taube’s theoretical framework, human cells develop resistance against insulin when its secretion reaches certain amount and excessive insulin leads to fat storage. Can such resistance be corrected? Assuming a man has been obese for 5 years and developed a high-carbohydrate dietary habit, can his body overcome this cell resistance and stop sending signals that turn off his physical addiction to carbohydrate? Without touching upon this aspect, Taubes summarized his weight loss method as a choice of choosing low-carbohydrate diet is obviously contradictory to his statement that weight gain is physiological and beyond willpower.


To conclude, Taubes’ explanations on how carbohydrate works and how our bodies accumulate fat are relatively convincing. Although Gary kept emphasizing that this book primarily served as a daily guidance, the writer feels a lack of biological and physiological knowledge has impeded deeper reflection of the content. This book opens a new window instead of paving an alternative path for us to understand the complex mechanisms of weight gain. Dialogues should be activated between the calorie-in/out paradigm and this carbohydrate hypothesis to improve the explanatory power of both sides.



References

BBC. Horizon. Sugar vs.Fat. Released on March.7.2014. Access at https://www.youtube.com/watch?v=Y1L-_jfJ09Y.

Bray AG, Nielson JS, et. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. American Journal of Clinical Nutrition. April 2004 vol. 79 no. 4 537-543.

Diet Doctor. Why we get fat-with Gary Taubes. Released in Sep.2012. Access at https://www.youtube.com/watch?v=l59YyXpCT1M

Food highest in calorie. Health Aliciousness.com. Access at http://www.healthaliciousness.com/articles/highest-calorie-foods.php

Food highest in sucrose. Nutrition Data. Access at http://nutritiondata.self.com/foods-000009000000000000000.html

Goodreads. Community Reviews. Why we get fat and what to do about it. Access at http://www.goodreads.com/book/show/8727466-why-we-get-fat?from_search=true.

Taubes, G. Why We Get Fat And What to Do About It. New York: Alfred A. Knopf. 2011. 288pp.


Horgan, John. Chewing the fat with diet journalist Gary Taubes. Scientific American. Oct.7,2014. Access at http://blogs.scientificamerican.com/cross-check/2014/10/07/gary-why-we-get-fat-taubes-speaks-out-on-diet-studies-including-his-own/

Top 10 foods highest in carbohydrates. Health Aliciousness.com. Access at http://www.healthaliciousness.com/articles/foods-highest-in-carbohydrates.php

Willett WC, Leibel RL. Dietary fat is not a major determinant of body fat. American Journal of Medicine. 2002;113 Suppl 9B:47S-59S.