If you are looking for a size zero figure, then following a vegan diet that includes no animal products could offer better results than other weight-loss plans, says a study.

"Vegetarian diets are more effective than non-vegetarian diets for weight loss," said researcher Ru-Yi Huang of E-Da Hospital in Taiwan.

The study reviewed the results of twelve diet trials, involving 1,151 dieters who followed a specific eating regime for between nine and 74 weeks.

Overall, individuals assigned to the vegetarian diet groups lost significantly more weight (around 2.02 kg) than dieters who ate meat and other animal products.

Vegetarians who followed a vegan diet lost even more weight. Comparatively, they lost around 2.52 kg more than non-vegetarian dieters. Vegetarians who consumed dairy products and eggs lost around 1.48 kg more than those on a non-vegetarian diet.

According to Huang, the abundant intake of whole grains, fruits and vegetables might play a role in the favourable results seen in vegetarian diets.

Whole-grain products and vegetables generally have low glycaemic index values and do not cause blood sugar levels to spike. Fruits are rich in fiber, anti-oxidants, minerals and protective chemicals that naturally occur in plants.

Whole-grain products contain soluble fiber. Such so-called good fiber helps to delay the speed by which food leaves the stomach and ensures good digestion.

The researchers found that people following vegetarian diets that prescribe a lower than normal intake of calories (so-called energy restriction) also shed more kilograms than those without any such limitations being placed on their eating habits.

The findings appeared in the Journal of General Internal Medicine.