One of the few diet pill ingredients that actually has been proven in many clinical studies, caffeine is a stimulant and a diuretic that aids significantly to weight loss. It is found in many diet pills currently on the market and in most of the effective ones.
A Word of Caution
Before jumping after a diet pill that contains a bunch of caffeine just because it is highly effective, you need to know your personal tolerance for caffeine. Different people react very differently to this supplement and those who can’t handle caffeine as well as others should steer clear of it.
Caffeine has been the topic of much research in regards to weight loss and exercise. It has been proven to aid in energy levels during workouts and to boost the metabolism. In one study the use of caffeine increased the metabolism by 6%. ((http://www.nature.com/ejcn/journal/vaop/ncurrent/abs/1602901a.html))
Another study found caffeine to significantly boost the endurance level of subjects during exercise:
“In this study a double-blind design was used to determine the effect of caffeine on time to exhaustion and on associated metabolic and circulatory measures. Eight male subjects ingested either caffeine (5 mg/kg body weight) or a placebo 1 hr prior to exercise at 85-90% of maximum workload.[...] The time to exhaustion was significantly longer during the caffeine trial than during the placebo trial. Serum free fatty acid levels were significantly different between trials. The decline in blood glucose levels was significantly less during the caffeine trial than during the placebo trial. There were no significant differences between trials for the other measures. It was concluded that caffeine increases time to exhaustion when trained subjects cycled intermittently at high levels of intensity.” ((http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=AbstractPlus&list_uids=7749424))
Those are both very considerable effects when considering caffeine as a supplement to lose weight or help improve your workouts. The list of research goes on and on. A quick search for caffeine will provide you with a slew of supporting studies.
Caffeine significantly aids in weight loss due to its ability to dramitically increase energy and endurance during workouts as well as increase your metabolism. While caffeine may not be for everyone, it is a highly effective weight loss supplement. Caution should be taken before using caffeine as it can it be hazerdous to your health if you do not know your tolerance level.