Think losing weight on an all-you-can-eat diet is the stuff of infomercials? Think again.

Obese subjects placed on a vegan diet -excluding meat and animal products, but not limiting calories – lost more weight than a control group that followed a low-calorie, low-cholesterol diet, in a collaborative study by George Washington University and Georgetown University.

The veg edge: approximately 13 pounds lost over 14 weeks for the vegan dieters, versus 8 pounds for the control group.

More recently, the same researchers reviewed 87 studies on vegan or vegetarian diets, concluding that the high-fiber, high-water, low-fat content of vegan or vegetarian diets – not calorie counting per se – was responsible for weight loss. Indeed, overweight individuals who “went vegan” lost about a pound per week, regardless of additional lifestyle changes made.

Other research found that vegetarian women weigh less. After evaluating the diet and health data of 56,000 Swedish women, Tufts University researchers found the meat eaters were significantly more likely to be overweight when compared to their vegetarian peers: 40 percent of carnivores, compared to 25 percent of vegetarians and 29 percent of flexitarians, or semi-vegetarians (those who avoided meat but ate fish and eggs).

If a slimmer figure isn’t enough incentive to go greener, how about a longer life? A study published in the American Journal of Clinical Nutrition found that a low meat intake was associated with a 3.6-year increase in life expectancy.

Yet another reason to minimize meat and make more room for plant-based protein on your plate: A recent Mayo clinic analysis of data from nearly 30,000 postmenopausal women found a 30 percent lower risk from heart disease among those who ate the most vegetable protein from beans and nuts in place of either carbohydrates or animal protein.

A large-scale analysis of dietary patterns and prostate cancer risk found that animal products such as meat and dairy were the strongest risk factors, while fruit and vegetable consumption had the most protective benefit.

Processed meat may be the unhealthiest of all, according to a study from the University of Hawaii and the University of Southern California, which found those who consumed the most processed meat had a 67 percent higher risk of developing pancreatic cancer. Diets rich in red meat and pork increased the risk by about 50 percent.

If you’re like most Americans, your problem isn’t getting enough protein and simple carbohydrates; your challenge (and health opportunity) is to increase consumption of fruit, vegetables and legumes.

Little changes can make a big difference. Add more fruit to your cereal (try frozen berries for convenience and freshness). Make a banana or a fruit cup your morning snack.

Have a vegetable-based soup with your lunch and, research suggests, you’ll also end up eating less. Same goes for dinner: Start with salad and you’ll consume fewer calories and far more nutrients.