A flexible take on vegetarianism, this approach involves a primarily plant-based diet supplemented with occasional protein.
Maria Condo

Like vegetarians, "flexitarians" eat a primarily plant-based diet composed of grains, vegetables, and fruits, but they occasionally obtain protein from lean meat, fish, poultry, or dairy. A quarter of Americans fit the description, consuming meatless meals at least four days a week, according to the American Dietetic Association (ADA).

Why it's here to stay:
Flexitarianism is exactly what dietitians, nutritional researchers, and public health advocates have been recommending for years. "It's about eating a varied diet that's low in saturated fat and high in fiber," says Milton Stokes, M.P.H., R.D., chief dietitian at St. Barnabas Hospital in New York City, and an ada spokesperson. Because the emphasis is on produce rather than protein, flexitarians are more likely than most Americans to meet the recommended daily intake of fruits and vegetables and the vitamins and minerals they contain.

What it means for you:
Studies show that people who follow this approach to eating generally weigh less and have lower rates of hypertension, heart disease, diabetes, and prostate and colon cancer. In one large study from Tulane University in New Orleans, researchers tracked the eating habits of more than 9,600 people over a 19-year period and found those who consumed fruits and vegetables at least three times daily lowered their risk of stroke by 42 percent, and their risk of cardiovascular disease by 27 percent.