Supplements are unregulated and unproven
Have you ever wondered how some people get so big? Rice flour!
From YouTube
The story makes an excellent point: supplements are not regulated and often hide behind a veil of proprietary secrecy. This is true for vitamins as well.
Listen to this Freakonomics podcast for a great segment about the politics of obesity where political science professor Eric Oliver argues that a lot of people are making a lot of money by drumming up an obsession with fitness and weight. Follow the money!