Many may not know that our daily energy expenditure consists of three components: Basal metabolic rate (BMR), diet-induced thermogenesis, and the energy cost of physical activity. Basal metabolic rate accounts for the largest portion of the total energy expenditure. About one-third to one-half of the total energy expenditure is used to maintain BMR – this is the energy used for the involuntary processes in the body such as respiration, circulation, cellular activity, and maintenance of muscle tone. Important factors that affect BMR are: Gender, weight, age, body composition, sleep, and environmental temperature. Males have the higher BMR than women; the heavier person, the higher the BMR; as we age, BMR generally decreases; people with higher percentage of body fat have lower BMR; when at sleep, BMR may be lower by 10 percent than when awake; BMR is increased in a cold environment because the body has to produce more heat to maintain normal body temperature.

The second component that constitutes our daily energy expenditure is called diet-induced thermogenesis. It is defined as the increase in heat production by the body after eating. There is energy expended when we digest the food we eat – for secretion of digestive enzymes, transport of nutrients, and the intestinal motility that occurs. When the body starts forming tissue reserves of fat, glycogen (storage form of carbohydrate in the muscle) and protein, this also calls for energy expenditure from 10 to 15 percent of energy intake. Diet-induced thermogenesis can account for up to 23 out of 100 calories when we eat complex carbohydrates, but only three out of 100 calories when we eat pure fats.  This is one reason why fatty meals are so fattening. Among the substances that are known to increase body metabolism are caffeine (from coffee and soda) and capsaicin (in hot peppers).

In animal studies, capsaicin from chili reduced adiposity in rats by enhancing energy and lipid metabolism, possibly by increasing catecholamine (epinephrine and norepinephrine) secretions. In some human studies, meals containing chili in lean young people have shown an increase in energy expenditure, increased fat oxidation in women or increased carbohydrate oxidation in men. Aside from chili, caffeine is another substance that is known to increase body heat production after intake. Small human studies have shown coffee-induced stimulation of energy expenditure in both obese and non-obese individuals.

Recently, scientists have also looked into an extract of the plant Piper Nigrum (commonly called Black Pepper) called Bioperine. This extract that usually comes as a dietary supplement is used by body builders and by those who wish to lose weight. Bioperine will cause the body to produce heat by burning brown fat deposits. The result would be an increase in body temperature, higher basal metabolic rate, sweating and losing body fat. Other than being able to stimulate increase in body heat, Bioperine was seen to play an important role in the nervous system. Bioperine increases the production of endorphins which are pain-relieving agents that are important to counter the effects of trauma. Another good thing about this body heat-producing substance is that it can help increase the bioavailability of nutrients like vitamins and amino acids – one thing that athletes and body builders would want from their supplement as it would be ideal for burning fat and developing muscle as well.

Because most people are interested in foods that induce body heat production for its possible weight loss effect, we suggested that before this should be tried, increase in physical activities must be highly considered the first step to inducing weight loss. Although some foods are natural means to increasing body heat production, inducing weight loss through this method may not be feasible for very long periods of time.