‘You Can’t Outrun a Bad Diet,’ Argue Researchers

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Large man lifting weights
Photo: Peter Muller/Corbis

What’s causing obesity to go up in the U.S., the U.K., and so much of the rest of the developed world, along with associated diseases like diabetes? If you ask most people, their response will be something like, “People are eating too much and they’re more sedentary than they used to be.” Researchers are spending a great deal of time trying to determine whether or not this is an accurate assessment and just how much of the blame should be parceled out to diet versus exercise.

In an editorial in the British Medical Journal, a trio of researchers led by Dr. Aseem Malhotra of Frimley Park Hospital in the U.K. argues that the focus on physical activity is wrong. And not only is it wrong, they write, but it’s also a convenient way for the companies selling us unhealthy stuff to sidestep culpability. Malhotra and his colleagues write that even over “the past 30 years, as obesity has rocketed, there has been little change in physical activity levels in the Western population” (endnotes replaced with links throughout). It doesn’t make sense to blame the obesity crisis on sedentary lifestyles, then — but given how diets have changed in recent decades, it does make sense to look to food, in particular the upward trajectory of carb and sugar intake.

Malhotra and his colleagues also echo an important point that’s consistently lost in this discussion: There’s really way too much of an emphasis on superficial aspects of weight. Yes, when people are severely overweight (or, for that matter, severely underweight), they’re likely to face significant health problems, but there’s a rather large gray zone that needs to be taken into account as well. In much the same way some technically overweight people have healthy metabolic markers, “Up to 40% of those with a normal body mass index will harbour metabolic abnormalities typically associated with obesity, which include hypertension, dyslipidaemia, non-alcohol fatty liver disease and cardiovascular disease.” That suggests that what people are eating is harming them, whether or not this harm is externally visible in the form of obesity.

And yet despite all this, the authors lament, there’s an endless focus on exercise and, more generally, calorie counting. They think that people should be paying more attention to where calories come from, and they think that giant food companies are being let off the hook too easily by the idea that if you just exercise a little more, it’s okay to indulge your soda habit.

While none of this stuff is clear-cut — there are a huge number of seemingly contradictory findings within the field of nutrition research, like the professor who lost 27 pounds and maintained his good health in general by counting calories on an all-junk-food diet — this is a compelling argument, and one that connects many of the dots of the obesity-crisis mystery. (There’s also a video in which Malhotra further expands on his his argument — not embeddable, unfortunately — over at the site Diet Doctor.)