Jenni Laidman

April 23, 2015

Exercise enthusiasts cannot work off the ill effects of an unhealthy diet, say the authors of an editorial published online April 22 in the British Journal of Sports Medicine.

“Let us bust the myth of physical inactivity and obesity,” the authors write. “You cannot outrun a bad diet.”

Physical activity levels in Western nations have remained flat during the past 3 decades, even as obesity rates have exploded. That observation is just one sign that calories, not lack of exercise, are driving the obesity crisis, argue Aseem Malhotra, MD, honorary consultant cardiologist at Frimley Park Hospital, United Kingdom, and science director for Action on Sugar, United Kingdom, and colleagues.

“However, the obesity epidemic represents only the tip of a much larger iceberg of the adverse health consequences of poor diet,” the authors write. They say that the Lancet global burden of disease reports concluded that poor diet contributes to more disease than a combination of inadequate physical activity, alcohol, and smoking. As many as 40% of people with normal body weight will suffer from metabolic abnormalities typically associated with obesity, the authors write, including hypertension, dyslipidemia, nonalcoholic fatty liver disease, and cardiovascular disease.

Dr Malhotra and colleagues blame food industry marketing for promoting exercise over diet, comparing food industry public relations with discredited tactics used by the tobacco industry in the past. They say Coca Cola “pushes the message that ‘all calories count’; they associate their products with sport, suggesting it is ok to consume their drinks as long as you exercise. However science tells us this is misleading and wrong.”

The kind of calorie matters too, they emphasize. Calories from sugar promote fat storage and hunger; fat calories induce satiety. For every 150 calories consumed from sugar, there is an 11-fold increase in the prevalence of type 2 diabetes independent of weight or physical activity levels compared with consumption of 150 calories of fat or protein.

“Celebrity endorsements of sugary drinks, and the association of junk food and sport, must end,” the authors write. “This manipulative marketing sabotages effective government interventions such as the introduction of sugary drink taxes or the banning of junk food advertising.”

Sara N. Bleich, PhD, associate professor, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, told Medscape Medical News that although exercise can do a lot of good things, including help people maintain a healthy weight, it is no substitute for eating right. Dr Bleich was not associated with the editorial.

“The take home message is, it’s what you eat, not how hard you try to work it off, that really matters when it comes to weight loss,” she said. Dr Bleich studies interventions to help people change eating behaviors.

“It may take you seconds to consume hundreds of calories that could take you hours to burn up,” Dr Bleich said.

The authors and Dr Bleich have disclosed no relevant financial relationships.

Br J Sports Med. Published online April 22, 2015. Extract

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