Fatty foods should not be demonised as the cause of obesity, contrary to popular belief, although they do raise the risk of coronary heart disease, according to an eminent nutritionist.
Tom Sanders, professor of nutrition and dietetics at King's College London, suggested dietary fats were more of a "thorny issue" than many realised.
He was giving the British Nutrition Foundation's annual lecture in London, entitled 'The role of fat in the diet quantity, quality and sustainability'.
"The evidence for fat and obesity is thin," he said.
Sanders presented the results of research, which showed that while levels of obesity had increased in recent years, the actual intake of dietary fat had decreased.
"Is there any relationship between intake of fat and prevalence of obesity?
None whatsoever," said Sander.
He described the results of a US study, which led to the view that: "This pathway of advocating a low fat diet was not the answer."
Following the popularity of the Atkins (low carbohydrate) diet several years ago, said Sanders, a major academic study published last year concluded: "Macronutrient composition fat, protein, carbohydrate doesn't matter.
The only thing that matters in terms of weight loss is calorie content.
Cutting calories down will lose weight."
However, Sanders added: "For heart disease, it is the type of fat that is important."
The main risk factor for coronary heart disease was elevated cholesterol, with genetic considerations and lifestyle effects, such as smoking, elevating the risk, he suggested.
The Food and Drink Federation is hosting a round table on December 15 to co-ordinate the industry's response to the Food Standards Agency's consultation on saturated fat and sugar in food.