Does a vegetarian diet help you lose weight?
Research has shown that, on average, people who follow a vegetarian diet eat fewer calories and less fat than nonvegetarians. Vegetarians also tend to have lower body weight relative to their height than nonvegetarians.
I recently study from Susan Berkow, PhD, CNS, and Neal Barnard, MD, of the Physicians Committee for Responsible Medicine (PCRM), a nonprofit group that supports vegetarian diets that when people want to lose weight, going vegetarian might be an advantage.
Berkow and Barnard reviewed 87 past studies by various researchers. They found that vegetarians were less likely to be obese and that vegetarian diets brought greater weight loss.
The reviewed studies generally used the word "vegetarian" for people who avoid meat but consume dairy products and eggs. "Vegans avoid all food products of animal origin," write Berkow and Barnard.
In weight loss studies, participants who had been randomly assigned to follow vegetarian or vegan diets lost more weight than those not on vegetarian diets.
Those studies were short and typically featured low-fat vegetarian diets. In several studies, participants were asked not to change their exercise habits. That way, their weight loss would have stemmed from diet, not extra exercise.
The review also included observational studies, in which participants weren't asked to change their diets. The observational studies showed that up to 6% of vegetarians were obese, compared with 5%-45% of nonvegetarians, and that vegetarians tended to weigh less than nonvegetarians.
Were those differences due to diet, or were other factors (such as exercise) important? The review doesn't provide the details of every study that was reviewed, so that's not clear.
Vegans and vegetarians typically eat diets that are higher in carbohydrates and dietary fiber and lower in calories, protein, total fat, cholesterol, and saturated fat, according to the review.
However, switching to a vegetarian diet doesn't guarantee weight loss. The basics of achieving and maintaining a healthy weight are the same for everyone: Eat a healthy, well balanced diet and limit your portions. Vegetarians - like nonvegetarians - can make poor food choices that contribute to weight gain, such as large portions of high-fat, high-calorie foods or foods with little or no nutritional value.
For this reason, vegetarian diets should be as carefully planned as nonvegetarian diets to make sure they are nutritionally balanced. Choose a vegetarian eating plan that is low in fat and that provides all of the nutrients your body needs. Be sure to include protein-rich foods - especially if you follow a vegetarian diet that limits fish, eggs and dairy products. Protein is not only an essential nutrient, but it also helps you feel full longer - which can curb your urge to snack.
A diet that largely consists of fruits and vegetables will contain fewer calories. But be cautious of what else you add to your diet. Substituting large quantities of cheese and peanut butter for meat will add a significant amount of fat and calories to your diet. Limit your portions of high-fat protein substitutes. In addition, opt for low-fat protein substitutes, such as dried beans, low-fat cheese, reduced-fat peanut butter and soy products.
Cooking methods and condiments also factor into your calorie intake. Instead of frying, try steaming, boiling, grilling or roasting foods. If you stir-fry, reduce the amount of oil you use. Also, use smaller amounts - or lower-fat versions - of sour cream, mayonnaise, cheese and salad dressing in your food preparation.