Delicious foods that help you diet? It sounds too good to be true. Load your shopping cart with lots of lean protein, fresh veggies, fruit, and whole grains, says food scientist Joy Dubost, PhD, RD. But grapefruit juice doesn't have any proven "fat-burning" properties -- it may just have helped people feel full. It sounds too good to be true. That means you feel full longer, which may stop you from eating more. Pick a square or two of dark over the milky version.
Studies involving humans are for the most part badly designed. A few quality studies have been carried out over the years, starting in 1998 with a double-blind, placebo-controlled trial of 135 adults over 12 weeks published in The Journal of the American Medical Association.
They found no evidence that hydroxycitric acid, the active ingredient in weight loss products made from garcinia cambogia, produced significant weight loss.