Experts from Britain and the US say eating healthily is more important than counting calories - a view not shared by some of their peers.

Doctors are being urged to promote the powerful benefit of healthy food rather than focusing on calories and handing out drugs.

The rising tide of obesity and unhealthy living should not be ignored, but the benefits of medicines to tackle the problem are "exaggerated", British and US experts say.

Instead, people should eat a Mediterranean-style diet, rich in oily fish, olive oil and nuts, and focus on the nutritional content of food rather than just calories.

The opinion piece, written in the journal Open Heart, said other changes, such as stopping smoking, also had major benefits.

Dr Aseem Malhotra, from Frimley Park Hospital in Surrey, England; James DiNicolantonio, from the Saint Luke's Mid America Heart Institute in Kansas in the US; and Professor Simon Capewell, from the University of Liverpool, said research had shown that simple steps could benefit health.

For example, drinking a sugary drink (150 calories) is associated with a significantly increased risk of Type 2 diabetes.

But a daily handful of nuts (30g of walnuts, 15g of almonds and 15g of hazelnuts) or four tablespoons of extra virgin olive oil (around 500 calories) is associated with a significantly reduced risk of heart attack and stroke.

Estimates showed that increasing nut consumption by two servings a week could stave off 90,000 deaths from cardiovascular disease in the US alone, they said.

The researchers argued that the global burden of disease "will clearly not be prevented by medications; it will require policy interventions that make healthier diet choices easier (the 'default option').

"The most powerful and effective policies include taxation on sugary drinks, and subsidies to increase the affordability and availability of healthier foods including nuts, vegetables and fruit, in addition to controls on the marketing of junk foods and clear package labelling.

"It is time to stop counting calories, and time to instead promote good nutrition and dietary changes that can rapidly and substantially reduce cardiovascular mortality."

But not everyone agrees with the opinion.

Victoria Taylor, senior dietitian at the British Heart Foundation, said the article reminded people to focus on their whole diet.

"But with around a quarter of adults in the UK already classed as obese and more than a third overweight, our energy intake does still need to be considered," she said.

Tom Sanders, professor emeritus of nutrition and dietetics at King's College London, said: "In my opinion, it is idiotic to suggest that calories don't count and then advocate a high fat diet."

"Obesity is only prevented if energy intake is balanced by energy expenditure. Even a healthy dietary pattern can result in weight gain if too many calories are consumed," he said.

"For example, the Mediterranean diet of Greece is often used to portray a heart-healthy diet. But Greece now has one of the highest rates of obesity in Europe."