In an article for a leading health journal the authors – who include British cardiologist Dr Aseem Malhotra, an outspoken critic of the food industry – accuse food and drink firms such as Coca-Cola of having wrongly emphasised how physical activity and sport can help prevent people becoming very overweight.
The truth, they say, is that while physical activity is useful in reducing the risk of developing heart disease, dementia and other conditions, it "does not promote weight loss".
"In the past 30 years, as obesity has rocketed, there has been little change in physical activity levels in the western population. This places the blame for our expanding waistlines directly on the type and amount of calories consumed."
The authors add: "Members of the public are drowned by an unhelpful message about maintaining a 'healthy weight' through calorie counting, and many still wrongly believe that obesity is entirely due to lack of exercise." '