It's Not Genes: People Are Fat Because They Eat Too Much

Arthur L. Caplan, PhD


May 27, 2014

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Hi. I am Art Caplan, from the Division of Medical Ethics at the New York University Langone Medical Center in New York.

Why are your patients fat? Why are people fat generally? Struggling with weight is a problem. I personally have done better with it lately, but it is a challenge. We all know we are in the middle of an obesity epidemic in the United States. Indeed, worldwide obesity is an increasing problem.

If you look at the medical literature, the answer is clear. The problem is in our genes. Again and again, in media reports and in articles that catch the attention of editors at the most prominent medical journals, the answer to why we are all fat is that we have bad genes.

Think about it. You go to a cocktail party. You are chatting with people and you start talking about weight. The person says, "I'm one of those high metabolizers (or low metabolizers)," hinting that there is a genetic or biological basis for their size. Or people will say to me, "I must have inherited bad genes. I just can't seem to keep weight off."

We love the genetic explanation. That is why it was so interesting to see a paper recently in the British Medical Journal[1] that looked in a very different, but I believe a more fertile, direction for understanding the obesity problem.

Researchers from the University of Cambridge conducted a very simple study. They wanted to know how many fast-food outlets are in Cambridgeshire, the county that includes Cambridge and the university. They also looked at where people commuted to work, and whether there was any association between going by these fast-food places and obesity and diabetes.

Bad Food, Not Bad Genes

Guess what they found? If you put a bucket of fried chicken out every half-mile along the route people take to work and back, they are fatter. There is a correlation between fast-food outlets and being diabetic or being fat.

The point is this: Genes certainly play a role in how people handle food, but if you live in a culture that overwhelms you with opportunities to eat junk food and fatty food, even the best genes can easily be overwhelmed.

We are that kind of country, too. We promote eating more food. I took a ride recently from Moosic, Pennsylvania, to Wilkes-Barre. Having read this article, I decided to count how many fast-food places I could see from the road in a relatively rural area. The distance was 13 miles. I counted 19 kings, arches, colonels, and so on. Fast food is ubiquitous. Bad food opportunities are everywhere.

If we are going to get a handle on the obesity epidemic, then we need to stop saying, "All you have to do is control your diet, and somehow manage the responsibility that your genes gave you." Telling people they have a genetic basis for obesity is kind of an excuse, or an easy way out.

We also must begin to say, "Hey, those places you drive past, those places that are advertising and marketing? They are dangerous for you. You might want to avoid them." I think we have to ask people and patients, "How often do you go? How often are you eating there? Do you realize that even if a place has a salad on the menu, if you get 3 Big Macs and French fries, it does not matter that a salad is on the menu?"

We must start taking more seriously the dangers that are out in the environment. We also should think about telling our patients that a lot of fast-food promotion and fast-food presence is leading to some of the problems that their kids have.

Maybe a better philosophy is to make it a special treat to go to one of these outlets, rather than going simply because you have run out of ideas about what to do in terms of getting a quick and easy meal. It may be quick. It may be easy. But as this study showed, it is dangerous.

Let us not point the finger of blame at our genes or say, hey, exercise some self-control [without providing some kind of support]. Let us realize that in a world in which temptation is put out all around us, that is a problem we have to discuss with patients too.

I am Art Caplan, from the Division of Medical Ethics at the NYU Langone Medical Center. Thanks for watching.


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