A preliminary study has found that green coffee beans taken daily can potentially speed up the process of weight loss.

The 22-week study carried out on 16 overweight men and women saw that a supplement of green (unroasted) coffee bean, on average, helped the individuals shed 17 pounds.

The research presented at the 243rd National Meeting & Exposition of the American Chemical Society (ACS) by Joe Vinson and colleagues, showed that an ounce of green coffee bean daily resulted in a 10 percent weight loss per day.

The participants aged 22-26, alternated between taking capsules of the extract and a placebo over the 22-week period. During this time, their diet and exercise regime was unaltered and they were monitored for their overall calorie and food intake.

Participants lost an average of 17 pounds during the 22 weeks of the study. It included an average of a 10.5 percent decrease in overall body weight and a 16 percent decrease in body fat, Vinson said adding that weight loss may have been faster had participants taken the full dose through the time period, instead of alternating between placebo pills.

Green coffee beans have been proved to assist weight loss in the past, but this has been the first study of its kind that uses such a high dosage of the extract.

Three reasons green coffee beans are thought to help weight loss:

Chlorogenic Acid: A substance which is more prominent in unroasted coffee beans.  The plant compound may have ''some effect on keeping down glucose absorption, which in turn helps reduce weight, Vinson says.

Dosage: A higher dosage, which was experimented with in the study, showed better overall results for participants.

Side Effects: No side effects were reported during the study, which resulted in the participants taking the capsules daily without hesitation, although  the capsules are extremely bitter and are best taken with a lot of water before a meal, says Vinson.

While the research showed promising results, the findings are considered preliminary and a further study including more people is planned for the future.

The study was carried out to try and find an alternative to prescription weight loss drugs that not only have low efficacy, but serious side-effects as well. Overweight and obese subjects in the US are now 68% of the population and the epidemic is growing in industrialized societies.