Any regime will do - just stick to it

If the bathroom scales reproach you with their tale of Christmas excess, here is a piece of advice: do not waste time trying to decide which diet to follow.

A comparison of four popular diet plans, including Weight Watchers and Atkins, has shown that it is not the diet you choose that determines how much weight you lose, but the rigour with which you follow it.

Low carb or no carb, high or low fat, protein rich or poor - it makes no difference.

The finding suggests scientists may have to change their approach to obesity. Instead of searching for the most effective diet to help people lose weight, they should be matching individuals to the diets that best suit them.

This new science, dubbed "nutrigenomics", could increase adherence rates among dieters and promote weight loss, they say. But there is currently no way for doctors to match a diet to an individual's "diet response genotype", the genetically determined way in which they react to certain foods.

It has always been known that success in dieting depends on the dieter's psychological determination to change. But the new research suggests that if a way could be found for individuals to select the right diet, it could ease the demands on willpower.

The finding comes as the dieting and fitness industries enter their peak January season, when millions of people seek to repair the damage caused by the festivities. But the evidence suggests that up to half will fail. The researchers found that between 35 and 50 per cent of those who started the four diets had abandoned them within a year.

In the study, Michael Dansinger and colleagues from the Tufts-New England Medical Centre in Boston, US, assessed adherence rates and the effectiveness of four popular diets - Weight Watchers (restriction of portion sizes and calories), Atkins (minimise carbohydrate intake without restricting fat), Zone (moderate macronutrient balance and glycemic load) and Ornish (restrict fat).

They followed 160 overweight or obese adults aged 22 to 72 who had high blood pressure, high cholesterol, high blood sugar or other health problems who were randomly assigned to one of the four diets. After two months of maximum effort, the participants were left to decide for themselves how closely they followed their diets.

The results showed that average weight loss after one year was 2.08kg for Atkins; 3kg for Weight Watchers; 3.2kg for Zone and 3.3kg for Ornish.

- INDEPENDENT