If you read weight loss advice in diet books, magazines, or on the Internet, you might conclude that a vegetarian diet is a guaranteed way to lose weight. Although surveys show that vegetarians tend to weigh less than meat-eaters, you may not experience sustained weight loss by turning vegetarian.
A recent study compared the eating habits of people before and after they began eating vegetarian. After following a self-selected vegetarian diet for six months, the calorie consumption of these people dropped by almost 200 calories per day.
Their weight did not change, but people seemed to be leaner. There were reductions in their waist and hip measurements, as well as their skinfold measure of body fat stores.
A British study did find weight differences between vegetarians and meat-eaters. This study divided more than 65,000 participants into four groups: meat-eaters, fish-eaters, lacto-ovo vegetarians (who eat eggs and dairy products but no meat), and vegans (who eat no animal products).
The body mass index (BMI), which is the most common way to measure body fatness, was at a healthy level in all groups.
But the meat-eaters had the highest BMI as a group, which brought them closest to being overweight. Fish-eaters and lacto-ovo vegetarians had similar, intermediate BMI averages, while vegans had the lowest. Among meat-eaters, 7 percent of the men and 9 percent of the women were obese. In the fish-eater and lacto-ovo groups, 3 percent of the men and 4 percent of the women were obese. Only 2 percent of the men and women vegans were obese.
The difference in weight among these groups probably comes from the difference in calorie intake. Fish-eaters and lacto-ovo vegetarians ate about 4 percent fewer calories than the meat-eaters. The vegans’ average calorie intake was 14 percent lower than the meat-eaters.
Anyone who fills up on more vegetables and fruits, like the vegans, should experience a drop in calories and weight because these foods contain fewer calories in the same size portion, compared to higher-fat meat or cheese dishes.
Age could help explain the weight differences in this study, too, since the participants estimated their calorie intakes a bit inaccurately. Vegans were much more likely to be in their 20s and 30s. Of the people in their 40s and 50s, two-thirds to three-quarters were meat-eaters.
This age allocation is significant because the average BMI increased one to two points between the ages of 20 to 40 in each eating group. The higher BMI among meat-eaters could reflect the greater proportion of middle-aged people in the group.
Portion control essential
Nevertheless, for people of all ages, the impact of vegetarian eating on their weight depends on how it affects their calorie consumption. A healthy plant-based diet – whether it is totally vegan or includes some dairy, fish, eggs, or meat – focuses on vegetables, fruits, whole grains and beans. This eating style, even with moderate amounts of nuts and healthful fats, is lower in calories than a diet with large amounts of fatty sausages and cheeseburgers.
You can still consume a lot of unnecessary calories with a vegetarian diet, however. A large proportion of the average American’s calorie intake comes from soft drinks and other sweetened beverages, chips, French fries and cookies – not meat or dairy products.
If you want to lose weight, look at where your excess calories come from. Try to fill up on low-calorie vegetables, fruits, whole grains and beans. This is the crucial part. You can choose to omit all meats or include some fish, poultry, or lean kinds of red meat. No matter which style of eating you choose, portion control is essential. Overeating even healthy foods piles up calories that prevent weight loss.
Nutrition Notes is provided by the American Institute for Cancer Research in Washington, D.C.© 2005 MSNBC Interactive