There can only be one thing worse than trying to squeeze yourself into a swimming costume, and that’s being a vegan. No meat, eggs or dairy – nothing that comes from animals. Is there anything interesting left to eat? Yes, there’s lots – according to vegans – including chickpeas, kidney beans, fortified soy products, fruit and nuts. So this week’s research linking vegan diet and weight loss is a triumph for the tofu burger. Vegetarian diets have previously been linked with a reduced risk of Type 2 diabetes, heart disease and dying from pretty much everything. But, more importantly – at least as far as summer magazine issues go – vegan diets haven’t been strongly linked with weight loss. This is partly because studies on weight loss and varities of vegetarianism have been small, lasted varying amounts of time and the subjects studied haven’t stuck to their diets.

The solution

This new study, a meta analysis published in the Journal of General Internal Medicine, adds up the results of the best studies that compare weight loss in vegetarian and non-vegetarian diets, and also lacto-ovo vegetarians (who drink milk and eat eggs) and vegans. The studies included 1,151 dieters who had followed a regime for between nine and 74 weeks. The diets included the Atkins diet and those recommended by the American Diabetes Association and the US National Cholesterol Education Program. Those who followed a vegetarian diet lost an average of 1.48kg more than those on other diets, while vegans lost 2.52kg more than the non-vegetarian dieters. The lead author, Ru-Yi Huang, says that wholegrain products that are rich in fibre may cause the stomach to delay in emptying and therefore delay feelings of hunger. Some of the individual pieces of research within the meta analysis had more dramatic evidence of weight loss – one study found a weight loss of 10kg at a year and 8kg at five years in vegetarians. A study in BMJ Open of 39 overweight people found that an “Eco-Atkins diet” – a low-carbohydrate vegan diet (with protein from soy and nut products) – led to 6.9kg weight loss over six months as well as lower cholesterol levels.

The British Dietetic Association says that vegetarian and vegan diets are suitable for every stage of life as long as they are well planned. There are many ways to lose weight, all of which involve eating less or at least expending more energy than you take in. Becoming a vegan is usually a lifestyle choice rather a diet – one that people make for many reasons, and feeling better in a two-piece is perhaps not the most common one.