Bad diet is a lifestyle cause of obesity, but a lack of exercise is not, says an editorial reviewing controversial questions about this established health risk. The article published in a journal from The BMJ says the problem “cannot be outrun by exercise.”

Share on Pinterest Commercial messages that say sugar and carbs are OK as long as you exercise are not true, say the authors.

Even the exercise done by athletes cannot counter a bad diet, say the authors, who cite evidence that while obesity has rocketed in the past 30 years, “there has been little change in physical activity levels in the western population.”

Excess sugar and carbohydrates, not physical inactivity, are to blame for the obesity epidemic, says the editorial.

The review, which aims to lead the opinion of sports medicine researchers and clinicians, is written by Dr. Aseem Malhotra, a UK cardiologist and consultant to the Academy of Medical Royal Colleges in London, with Prof. Tim Noakes of the Sports Science Institute of South Africa in Cape Town, and Dr. Stephen Phinney, professor emeritus of medicine at the University of California Davis.

The healthy choice of regular physical activity is not dismissed, however, because while these experts claim it “does not promote weight loss,” evidence shows that it “reduces the risk of developing cardiovascular disease, type 2 diabetes, dementia and some cancers by at least 30%.”

But poor diet is a bigger risk – it “generates more disease than physical inactivity, alcohol and smoking combined.” The authors support this claim with information about the global burden of disease published by The Lancet.

The editorial, published in the British Journal of Sports Medicine, continues by citing a 2013 review of the medical literature for metabolic syndrome, which asks why children are developing this cluster of cardiovascular risk factors.

That article, first-authored by Dr. Ram Weiss, a pediatrician at the Hadassah Hebrew University School of Medicine, Jerusalem, Israel, concludes that while obesity contributes to the syndrome, it is “unlikely” to be an “initiating factor.”

And the present authors cite that “up to 40% of those with a normal body mass index will harbor metabolic abnormalities typically associated with obesity, which include hypertension, dyslipidemia, nonalcoholic fatty liver disease and cardiovascular disease.”

Malhotra, Noakes and Phinney – who are well-known for their opinions on diet, exercise and health, having published widely through popular books and the media – add about the phenomenon in normal-weight people:

“This is little appreciated by scientists, doctors, media writers and policymakers, despite the extensive scientific literature on the vulnerability of all ages and all sizes to lifestyle-related diseases.”