Says Dr. Weil, While exercise, quality sleep and a healthy diet are the best ways to lose weight and keep it off, some people will still be tempted to take shortcuts and try weight-loss pills. If this is true for you or someone you care for, be sure to avoid products with these ingredients:
  1. Chitosan: A derivative of chitin, a substance found in the shells of insects, crabs, lobsters and other crustaceans. Claimed to bind fat, chitosan may inhibit the absorption of certain nutrients essentially for good health in humans.
  2. Pyruvate: A naturally occurring enzyme that allegedly forces every cell in the body to work harder. Although it sounds promising, there is little evidence that it works.
  3. Ephedra (ma huang): The active chemical in ma huang is ephedrine, which has been banned by the FDA, and can be dangerous when combined with other stimulants or included in weight loss products.

I recommend walking as a form of exercise that is effective for overall health (it strengthens almost every major organ in the body, promotes bone density, and boosts the immune system) and for weight loss. Aim for 45 minutes most days of the week.

 

http://www.drweil.com/drw/u/TIP05485/3-Things-Not-to-Do-to-Slim-Down.html