Researchers at the Scripps Clinic of San Diego found that people who at half of a grapefruit or drank a glass of grapefruit juice before every meal lost an average of 3.5 pounds over a three-month period, even though they did not diet or increase their exercise rout

Researchers attribute the loss to enzymes in grapefruit that help reduce insulin levels and encourage weight loss.

But watch out:

grapefruit can interact harmfully with certain medications!