there are 9 calories per 1 gram of fat and 6 calories per gram of carbs and protein
if you want to lose weight, you need to do a mixture of aerobic exercise and weight lifting. when you lift weights, you build lean muscle mass which increases your metabolism. the aerobic exercise will expediate fat loss. as for diet drugs like metabolife/xenadrine/etc-they all contain ma huang or ephedra, which is basically herbal speed. when such drugs are combined with caffeine, the effects can sometimes cause heart attack or stroke. though i've taken diet pills in the past, i don't do that anymore because they made my heart feel like it was going to burst out of my chest and i was always sweating. also, when dieting, be sure you eat at least 1200 calories a day to keep your body from going into 'starvation mode.' if it does this, your body will digest your lean muscle and start storing fat, so when you stop dieting, you'll gain weight back plus have more fat than before.