Food supplements now a days are becoming very popular for losing weight as well as gaining weight .Most of the gyms are now recommending various food supplements without knowing their side efffects.Many of the food supplements are not acknowledged and regulated by the Food and Drug Administration Board. Secondly many of them have steroids which give a feeling of high energy as a immediate response but in long term they have various side effects on liver and kidney....some are even causing osteoporosis by draining out calcium from the body ..so I agree with Vik that losing or gaining weight naturally is the best way.