High Protein, Low Fat & Low Carbohydrate Diets

Protein, fat and carbohydrates belong to a class of nutrients called macronutrients. Each of these macronutrients contains calories and general recommendations are provided as a percentage of calories. According to the recommendations in 2011, carbohydrates should comprise 45 to 65 percent of calories, protein should comprise 10 to 35 percent of calories and fat should comprise 20 to 35 percent of calories. Different types of diets tweak these general recommendations in varying ways.

High-Protein Diet

The theory behind a high-protein diet is that consuming most of your calories in the form of protein-rich foods and avoiding excess carbohydrates can help you lose weight. According to EveryDiet.org, high-protein diets generally suggest eating 1g of protein for every pound of body weight. If you are 120 pounds, a high-protein diet suggests 120g of protein daily. Normal recommendations for protein are 0.8g of protein for every 0.5 pounds, which translates to approximately 44g of protein per day for a 120-pound person.

Considerations

It is important to note that the American Heart Association does not recommend following a high-protein diet for weight loss. Eating too much protein may increase your risk of kidney disease, liver disease and osteoporosis. In addition, many popular protein-based foods also contain high amounts of saturated fat. Eating too many of these foods can increase your risk of coronary artery disease, diabetes and stroke.

Low-Carbohydrate Diet

Proponents of a low-carbohydrate diet claim that carbohydrates are to blame for weight problems. Low-carbohydrate diets tend to place a restriction on carbohydrate intake while allowing moderate amounts of fat. Popular low-carbohydrate diets, such as the Atkins diet and South Beach Diet, allow 55 to 65 percent of your calories to come from fat and 30 percent of calories to come from protein, while restricting carbohydrate intake to less than 20 percent of calories.

Low-Fat Diet

The theory behind a low-fat diet is that dietary fat is directly related to body fat. Proponents of a low-fat diet claim that reducing the amount of fat in your diet can help you lose weight, as well as lower your risk of heart disease.

Low-fat diets generally restrict fat intake to 10 to 19 percent of calories. According to "Nutrition and You" by Joan Salge Blake, low-fat diets are usually high in carbohydrates, allowing more than 65 percent of calories to come from carbohydrates and 10 to 20 percent of calories to come from protein.