High protein diet: A high protein diet is a type of weight loss plan that emphasizes consumption of high-protein-containing foods. There are many different kinds of high protein diets. Many high protein diets may be risky for overall health because they stress the consumption of meats and high protein foods containing saturated fat and a high percentage of overall fat. According to the American Heart Association guidelines, adults who are trying to lose weight and keep it off should eat no more than 30 percent of total daily calories from fat and less than 7 percent from saturated fat, which is difficult or impossible with many high protein diets. High protein diets may also restrict intake of important carbohydrates and low-fat dairy products.