Thermogenic, or heat-generating foods are low in calories but require substantial energy to digest, thus raising your metabolism after you eat them. Since a higher metabolism burns more energy, thermogenic foods can aid in weight loss and can be incorporated into many diet plans.
Calories come from fats, proteins and carbohydrates. Fats are the least thermogenic foods and proteins are the most. Some carbohydrates -- like fruits and vegetables -- are moderately thermogenic.
Broccoli is a low-calorie vegetable that is packed full of both calcium and fibre. The fibre in broccoli requires energy to digest; however, it has little caloric value. Eat broccoli raw or in stir-fries and casseroles.
Low in calories, a grapefruit is one of nature's most thermogenic fruits. Unlike some other fruits, grapefruit has a naturally low sugar content and can aid in literally dissolving fat and cholesterol.
Cayenne and Other Hot Peppers
Hot peppers have a natural hot spice that produces a thermo effect in the body, thus raising the metabolism. Like diets that recommend cinnamon and other spices for this very reason, hot peppers will also kick your metabolism into action.
Apples are low in calories and natural sugars, with a big dose of fibre in every serving. Both the skin and meat in an apple help cleanse the digestive system and burn calories doing so. Pure applesauce can be substituted for whole apples.
There's a reason that cabbage can cause intestinal gas - it puts the digestive system to work. People who eat cabbage regularly have a lower incidence of colon cancer than others. You can eat cabbage steamed or raw in salads or coleslaw.
The age-old diet staple, celery is extremely low in calories and high in fibre. In fact, celery requires more energy to digest and absorb than it provides the body. Thus, it is the perfect food for those on a thermogenic diet.
Like grapefruits, the acid in lemons helps rev up the metabolism. Lemons are naturally low in calories and provide loads of vitamin C. Squeezing lemon juice into water and other drinks can be an easier way to consume the fruit than simply eating it.