Your pulse should be substantially increased and you should be perspiring. Exercise is more important than diet. Caffeine is contained in many drinks especially coffee, tea, and cola beverages. Most people drink these beverages after a meal when their appetite suppressant effect is wasted. In order to use caffeine as a diet aid you should drink one of these one hour before a meal.
Coffee has the most caffeine, tea somewhat less, and the cola beverages least of all.
Drink only diet colas since regular colas contain 200-300 calories. Caffeine can also be purchased without a prescription. Take one tablet an hour before meals. There is a new drug which can help you lose weight. It blocks absorption of fat.