The grapefruit diet originally appeared to be just a fad. But now a new study suggests that consuming grapefruit may help reduce body fat. Researchers from Scripps Clinic in San Diego studied 100 people divided into three groups: The first ate half a grapefruit with each meal, the second drank 8 oz of grapefruit juice three times a day, and the third consumed no grapefruit or grapefruit juice. At the end of the trial, reseachers found that without making other changes to their food intake, the average weight loss in the grapefruit and grapefruit juice groups was about four pounds, with several subjects losing about 10. The scientists believe that the fruit may have chemical properties that reduce insulin release, even though they are not certain of the mechanism behind the grapefruit-stimulated weight loss. Another explanation could be that grapefruit contains naringin, a flavonol that prolongs the thermogenic effect of caffeine. Naringin has recently been found to have some interesting metabolic effects. A study found that naringin reduced the symptoms of the metabolic syndrome (i.e., obesity, high triglycerides, insulin resistance) when administered with a high-fat diet. Bodybuilders should consume naringin when trying to get leaner for a competition.
P. Pu et al., “Naringin ameliorates metabolic syndrome by activating AMP- activated protein kinase in mice fed a high-fat diet,” Archives of Biochemistry and Biophysics, 2011