The caffeine in coffee raises basal metabolic rate, the rate the resting body burns calories. As basal metabolic rate increases, fat decreases and the body sheds unwanted pounds. In medically supervised weight-loss programs, those who supplement a low-calorie diet and regular exercise with caffeine lose a little more weight. Not much, but enough to include caffeine in some weight-loss programs. However, caffeine only helps those who are severely obese, weighing well over 20 percent more than their recommended weight. It does not help those with more modest weight-loss goals — 5 to 10 pounds.
Coffee and tea contain caffeine and may cause jitters, irritability, insomnia and addiction.
When people say “ephedra,” they usually mean the Chinese variety ma huang (E. sinica). Ma huang increases metabolic rate, the speed the body burns calories. It also depresses appetite a bit. This combination of effects led to studies of the herb (actually chemically isolated ephedrine) for weight control, usually in combination with another stimulant, caffeine.
In physician-supervised weight-loss programs that include a low-fat diet and regular exercise, treatment with a combination of ephedrine and caffeine has increased weight loss by about 5 percent. In other words, a person who loses 100 pounds without ma huang might lose 105 with it.
In a 3-month trial, Danish researchers showed that compared with overweight women taking medically inactive placebos, those taking oral ephedrine (20 milligrams three times a day) lost somewhat more weight. And in a 2-month study, Italian researchers found that overweight women lost more weight if they supplemented a low-calorie diet with oral ephedrine (50 milligrams three times a day).