Morality and Fat?

Last week NYU psychology professor, Geoffrey Miller got himself into hot water for posting a tweet that read: “Dear obese PhD applicants: if you didn’t have the willpower to stop eating carbs, you won’t have the willpower to do a dissertation. #truth.”


Aside from Professor Miller’s clear lack of understanding of nutrition (it’s not just about carbs) his tweet brings up an important point regarding obesity. We here in the US don’t often treat obesity solely as a potential health problem, rather we treat it is a moral issue. This is the result of prejudice rather than reason and is not helpful at all to anyone who is trying to lose weight. So to address the question of whether we should be viewing body weight as a moral issue we really need to step away from our cultural perceptions and look at our biology.

Body fat is just stored energy, if you consume more energy than you expend, you store it as fat. Our bodies have evolved over several hundred thousand years to survive in our environment; one of the ways that we did so was to adapt a way to store food energy, which allowed us to eat enough to fuel both our present need and to store energy for later when the food supply may be scarce, like during periods of famine. Our DNA doesn’t know that those of us in the affluent middle classes of the developed world have regular access to far more Calories than we need (1). By influencing us to eat more than we need, our genes allow us to store energy for the future, which enables proper development and guards against starvation (2). One of the things that happen when we diet and lose weight is that our resting metabolism slows down. In other words our bodies get more efficient and use less energy, which is certainly a good adaptation to prevent starvation, but a major pain for those of us who want to lose weight (3). Our bodies don’t only slow down our metabolism when we cut back on calories and lose weight, they also signal us to be hungrier (4). Furthermore, there have been over 600 genes identified that play a role in weight gain and obesity (5).

Now, while it is true that our bodies have evolved to hold onto the food that we eat and drive us to eat more than we need, I am not suggesting that biology justifies us in abandoning our efforts to improve our health by eating well and making positive lifestyle choices; we are thinking animals and it is now, as it always will be our own responsibility to take care of ourselves.  I am, however, suggesting that if you are a person who struggles with your weight, you have not morally faltered. There will always be those who disagree with me on this point but I am curious as to what their goals actually are with weight loss. It is probably not health.

According to historian and author Peter Stearns (6) the attitudes in the United States about fat result from our cultural need to morally compensate for excessive and wasteful consumerism. The problem with this line of moral reasoning is that it creates an unfortunate paradox, because our biological drive to eat is motivated by the need to store energy for later, which, contrary to being wasteful, is, from the physiologic perspective, actually a very thrifty thing to do. In the case of body fat, our cultural and biological perceptions of thrifty behavior are in dynamic conflict with each other.

Attaching morality to this problem can cause us to believe that unsuccessful attempts at weight loss are an indication of our own moral shortcomings, which can lead us to search for implausible or even harmful alternative solutions.  If, however, we keep in mind that weight loss is a physical and mental challenge that has nothing to do with our moral value it is possible to see that it is completely unwarranted to deem our lives unworthy simply because we have to struggle with something.

So to Professor Miller I say this: Get your biases and prejudices under control, Sir before you post foolish comments for the world to see. You are free to be a sanctimonious pedant in your private life but as an academic and a potential thought leader you have a responsibility to demonstrate better critical thinking.


  1. Statistics from the Food and Agriculture Organization of the United States. Data spreadsheet available at:…/FoodConsumptionNutrients_en.xls
  2. Tooby, J., Cosmides, L. 1990. “The Past Explains the Present: Emotional Adaptations and the Structure of Ancestral Environments.” Ethology & Sociobiology, 11: 375-424.
  3. Leibel, R. Rosenbaum, M., Hirsch, J. 1995. “Changes in Energy Expenditure Resulting from Altered Body Weight.” New England Journal of Medicine, March 9 332(10): 621-628.
  4.  Jhanwar-Uniyal, M., Beck, B., Jhanwar, Y.S., Burlet, C., Leibowitz, S.F. 1993. Neuropeptide Y projection from arcuate nucleus to parvocellular division of paraventricular nucleus: specific relation to the ingestion of carbohydrate. Brain Research 631:97-106. This study shows one of the mechanisms by which our bodies make us hungrier when calories are low an increase in a neurotransmitter called neuropeptide Y, which causes cravings for carbohydrate, a quick energy source, to increase. This stuff gets released in really high amounts during calorie reduction, which is, of course, interpreted by the body as starvation.
  5. Pérusse L, Rankinen T, Zuberi A, Chagnon YC, Weisnagel SJ, Argyropoulos G, Walts B, Snyder EE, Bouchard C. The human obesity gene map: the 2004 update. Obes Res. 2005 Mar;13(3):381-490.
  6. Stearns, P. Fat History: bodies and beauty in the modern west. 1997. New York, NY :New York University Press.

Healthy Skepticism: High Fructose Corn Syrup

Recently a friend and colleague of mine lost a noticeable amount of weight and I asked him about it. He told me that he had recently switched over from regular soda to a so-called “throwback” soda that is, as he put it “healthier because it has real sugar instead of high-fructose corn syrup.” He further explained Pepsi throw backthat he has lost 12 pounds since he made the switch and that he feels a lot better now. I must admit I was pretty impressed by the fact that he lost weight by changing his corn-syrupy ways.

Corn syrup is believed by many to be very unhealthy and is often accused of being a major player in the rise in obesity that has occurred since the 1970s. Of course I am skeptical of the claims made about corn syrup because, at least as far as weight management goes, the evidence still indicates that calorie balance (what you consume compared to what you burn) is of the greatest importance. This colleague of mine, however swore by his plan and further there was obvious visible evidence that he had lost weight…I could see it with my own eyes.

Based on that conversation and the general fact that this colleague is a smart guy whose judgment I am inclined to trust, I found myself believing that there may be some truth to the corn syrup claims. The next day, however, I ran into him at the gym. We started talking and he told me that when he decided to give up corn-syrup he also had decided to start working out and that he was now also using an app on his phone that helped him track his Caloric intake so he can avoid eating too much. I asked him if he thought it was possible that the exercise and Calorie restriction might be why he’s lost weight and feels so much better rather than just the corn-syrup. He said it was possible but that he didn’t think so, he felt extremely confident that it was in fact the corn syrup.

Whether corn-syrup is bad for us is debatable (about which more in a bit), however it is very important to remember why, when wading through information on this or any scientific topic, testimonial or anecdotal evidence has very little value as scientific evidence. Anecdotes like the one offered to me by my colleague (who is very astute and intelligent) often seem convincing.  However, particularly with health matters, it is easy to misalign cause and effect. A subtle yet pervasive reason for this is something called the Fallacy of False Cause, an oft made mistake in which we assume that two events are causally connected.

a rooster crowingIf, for example, I observed that every morning, just before sunrise, a rooster crowed then concluded that it was the rooster crowing that caused the sun to rise, I would be committing this fallacy. Okay so this example seems a bit far-fetched but think about my friend who, while he gave up corn-syrup, also reduced his Caloric intake, started exercising, and lost weight, then concluded that his weight loss was attributable to the lack of corn syrup rather than all of his hard work and discipline. This despite the fact that research has proven time and again that eating less and exercising more is the most effective path to healthy weight loss.

High-fructose corn-syrup (HFCS) was developed in the 1960s and has since been increasingly used in the food supply as a sweetener because, in the U.S., it is significantly cheaper than cane or beet sugar. HFCS is not meaningfully different in composition or metabolism from other fructose-glucose sweeteners like sucrose (otherwise known as refined sugar or just sugar) but it does account for roughly 10% of the Calories we consume daily in the U.S. and for roughly 42% of added sweeteners in the food supply,  which is quite significant.


There has been a substantial amount of research on the topic of HFCS. In a 2004 review, Bray and Colleagues point out that the consumption of HFCS has increased substantially since its introduction and conclude that this increase may play a role in the rising levels of obesity. While this is a well-written review with sound conclusions it’s important to note that the authors blame an increase in HFCS consumption for the rise in obesity. This does not provide any damning evidence against corn-syrup as a food; it merely shows that we are consuming too much of it. Further, in a 2007 review by Forshee and colleagues the authors point out that the ratio of fructose to glucose in the U.S. food supply has not appreciably changed since corn syrup was originally introduced, they further conclude that based on the available evidence, HFCS does not contribute to weight gain and obesity any differently than other nutrients do. These conclusions are supported as well in separate reviews by White, and by Moeller and colleagues.  

Based on the available evidence it is clear that HFCS can indeed lead to caloric imbalance when we consume too much of it. However the same could be said of “natural” sugar.  There is not a lot of doubt that HFCS is a pervasive ingredient in many processed foods, however to assume that it is the cause of obesity because it is inherently hazardous, rather than factoring it in to the big picture is a more subtle, and perhaps more disruptive example of the fallacy of false cause.