You don't need to do 'one iota' of exercise to lose weight, says scientific study

Obesity crisis has been generated through a worsening of our diets – rather than a rise in sedentary lifestyles

Obesity can be beaten by simply following the right dietary plan, says the piece (Getty Images)

The cause of obesity is a bad diet rather than a lack of exercise, according to a group of international experts.

In an article discussing whether food, sedentary lifestyles or a combination of the two are responsible for the rapidly growing obesity epidemic, doctors said the obesity crisis had almost nothing to do with the amount of exercise we take part in.

They say that while frequent physical activity is vital in reducing the risk of the developing heart disease, dementia and a number of other conditions, it “does not promote weight loss.”

Writing in The British Journal of Sports Medicine the authors, who include cardiologist Dr Aseem Malhotra, an outspoken critic of the food industry for a number of years, claim that food and soft drink companies have incorrectly emphasised how physical activity and sport can prevent people from obesity.

“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.

“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.”

They likened the actions of the food industry as “chillingly similar” to those used by the tobacco industry and said that endorsements of sugary drinks and the association of junk food with sport must stop.

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

They go even further in challenging conventional ideas eating trends as they say that athletes and those looking to avoid excess weight gain should adopt a diet that is high in fat but low in both sugar and carbohydrates.

“Fat, including ketone bodies, appears to be the ideal fuel for exercise. It is abundant, does not need replacement or supplementation during exercise, and can fuel the forms of exercise in which most participate.”

The piece also calls for celebrities to forego their promotion of sugary drinks, calls on health clubs and gyms to stop selling them and denounced “manipulative marketing” for the sabotage of government efforts to introduce taxes on sugary drinks and to ban junk food advertising.

Speaking to the BBC, Dr Malhotra said that an obese person does not need to do “one iota of exercise to lose weight,” they just needed to “eat less.”

However, Professor Mark Baker, of the National Institute of Health and Care Excellence, which recommends “well balanced diets combined with physical activity,” said that it would be “idiotic” to rule out the importance of physical activity.

Professor Susan Jebb, professor of diet and population health at Oxford University, told the Guardian: “The authors fail to note that that weight loss programmes which combine diet and physical activity are the most successful route to weight loss in both the short (three to six months) and medium term (12 months)”.

Catherine Collins, of the British Dietetic Association, said that the authors had “incomplete evidence” for their claims and that the doctors had downplayed the metabolic and physical health benefits of undertaking even moderately intense exercise.

According to a 2014 study obesity is reaching global “crisis proportions”.

The Mckinsey Global Institute said that the disease cost the UK £47billion in annual costs, including treatment and losses in productivity. It suggests that this is about the same as smoking and armed conflict and greater than both alcoholism and climate change.