For whatever this is worth to you:

"Green Tea: Consider green tea as your beverage of choice if
you're trying to lose weight. People given green tea extract
burned more total and more fat calories than those given
caffeine or placebo in a study published in American Journal
of Clinical Nutrition." (Source: Joann Bally, Exercise Guru from http://www.exercise-tips.com - one of 500+ sites at lifetips.com)

Green tea extract is available as a nutrional supplement.

I also recall that my doctor once told me that extra zinc in the diet helps with weight loss.