To lose weight you need a good diet, not exercise
Physical activity is useful in reducing risks like heart disease, but does not promote weight loss
Physical activity is useful in reducing the risk of developing conditions like heart disease and dementia, but "does not promote weight loss."
"You cannot outrun a bad diet," according to an article for the British Journal of Sports Medicine - a leading health journal - whose authors include British cardiologist Dr Aseem Malhotra, an outspoken critic of the food industry.
Apparently a bad diet is responsible for more health problems than physical inactivity, alcohol and smoking combined.
Food and drink firms have wrongly emphasised how physical activity and sport can prevent people becoming overweight, but that is not the case, according to the doctors.
"In the past 30 years, as obesity has rocketed, there has been little change in physical activity levels in the Western population," the study reported. "This places the blame for our expanding waist lines directly on the type and amount of calories consumed."
The researchers added: "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. That false perception is rooted in the food industry's public relations machinery, which uses tactics chillingly similar to those of big tobacco... denial, doubt, confusing the public and even buying the loyalty of bent scientists, at the cost of millions of lives."
However the article was dismissed by the food industry and a few experts in diet, obesity and health. "The benefits of physical activity aren't food industry hype or conspiracy as suggested. A healthy lifestyle will include both a balanced diet and exercise", said Ian Wright, director general of the Food and Drink Federation.
The Food and Drink Federation is a trade association representing producers and retailers.