WHERE’S THE BEEF? CHECK YOUR SCALE
A vegan diet may help you lose a few extra pounds
For those hoping to shed some wintertime weight gain, research suggests that going vegetarian — or even vegan — can help.
When scientists looked at the body mass index of more than 37,000 Britons of all ages in 2003, they found that while the average male meat-eater had BMI of about 24.4, just shy of being overweight, the average vegan had BMI of 22.4. Among women, the patterns were similar. A 2009 study of Seventhday Adventist church members across North America showed an even more striking difference in BMI: more than five points between those on an omnivorous diet (28.8) and those eating only plant-based foods (23.6).
You could easily explain such findings by citing general differences in lifestyle choices between vegans and meat-lovers. Scientists have found that people on plantbased diets tend to be more healthoriented than the rest of the society: Vegans drink less, smoke less and tend to exercise more.
Yet experiments in which people are randomly assigned to different diets suggest that vegetarianism can be helpful in dropping extra pounds, no matter your life philosophy or your attitude toward treadmills. However, most such studies were done on rather small samples — some on as few as 16 people. A meta-analysis that took into account 12 trials involving well over 1,000 adults found last year that people on vegetarian diets lost, on average, 4.4 pounds more than those following other nutritional plans. Those who ate exclusively plant-based foods and eschewed all dairy and eggs — a vegan diet — slimmed down the most: on average, 5.5 pounds.
Fighting excess pounds with plant-based eating may lead to better health. Studies have shown that following vegetarian diets lowers the risk of diabetes, heart disease and even cancer.
“Nothing is as important, in my opinion, as energy density and the fibre content of such diets,” says Jim Mann, a professor of nutrition at the University of Otago in New Zealand. “A strict vegetarian has to eat a mountain of food in order to have enough calories.”
Experiments that focused specifically on fibre have pointed at that nutrient’s propensity for keeping unwanted pounds away.
“There are two different types of fibre — insoluble fibre and soluble fibre,” says University of South Carolina nutritionist Brie TurnerMcGrievy. “Insoluble fibre is just bulk, so it physically fills you up, whereas soluble fibre has low glycemic index, so it doesn’t spike your blood sugar really high. It’s digested slowly, and so you don’t have this ‘I feel full’ and then all of the sudden 30 minutes later, ‘I’m hungry again.’ It keeps you satiated.”
Vegan diets, relative to most North American diets, aren’t loaded with protein, often touted as a great aid in weight loss.
According to Mann, protein has “little long-term significance” in shedding extra pounds and keeping them off. In experiments, highprotein diets do help with faster weight loss and with keeping appetite under control, but these effects tend to disappear after a year.
“In high-protein diets,” TurnerMcGrievy says, “you are depleting your glycogen stores and the water that goes along with them, so you are going to lose a lot of weight. For some, that’s very motivating — but that’s not really body fat you are losing, that’s water.” That’s not the case with vegetarian diets, which always “contain adequate carbohydrate so they wouldn’t produce the glycogen and water loss.”
Mann cautions against obsessing with mechanisms by which vegetarian and vegan diets might help you lose unwanted weight.
“It’s very important not to try to identify just one factor because then people say, ‘Oh, I will just have that one factor.’ They will just take a fibre pill. It’s a great risk to oversimplify nutrition.”
Sometimes the most important thing in a diet is being able to stick with it, and the idea of going meatless may be off-putting. “We usually tell people to try the vegetarian diet for three weeks. It’s less scary that way — you are not doing it forever, you are doing it for three weeks. But that gives you a chance to try it out and get your taste buds adjusted,” says Turner-McGrievy.