Eating half of a grapefruit three times per day before meals appears to help people shed unwanted pounds, according to new study findings reported this week.
Moreover, regular grapefruit-eaters experienced a decrease in insulin, which in excess can increase the risk of weight gain and cardiovascular problems.
These findings suggest that adding grapefruit to your diet may be a good idea, a study author told Reuters Health.
“There’s something inert about fresh grapefruit that does help you with weight loss,” said Dr. Ken Fujioka of the Scripps Clinic in San Diego, California. “All in all, I would recommend it.”
In an interview, Fujioka explained that people have been espousing the “grapefruit diet” ever since the 1930s, and the concept has resurfaced from time to time over the years.
To investigate grapefruit’s effect on weight loss, Fujioka and his colleagues asked 100 obese people who were not trying to lose weight to eat grapefruit in various forms, and recorded how their weight changed over 12 weeks.
Three times per day before each meal, each group of patients either ate one-half of a grapefruit, or drank a glass of grapefruit juice, or took a pill containing grapefruit extracts, or drank apple juice. Participants were told not to vary their eating habits from before the study.
By the end of the study period, people who ate fresh grapefruit had lost 3-1/2 pounds “without doing anything,” Fujioka said. Moreover, these patients also experienced a decrease in insulin, a “surprising” finding, the researcher said.
He noted that grapefruit juice and pills of grapefruit extract were less helpful in shedding pounds. However, both fresh grapefruit and the juice appeared to encourage weight loss in people with metabolic syndrome - which includes several disorders such as abdominal obesity, high blood pressure, elevated blood sugar and unhealthy cholesterol levels that set the stage for type 2 diabetes, heart disease and stroke.
Fujioka explained that previous research has shown that grapefruit does not ramp up metabolism, suggesting that the fruit may encourage weight loss by lowering insulin levels.
He added that fans of the low-carbohydrate diet might want to consider making an exception for grapefruit. “It doesn’t act like a ‘bad carbohydrate,’ so to speak,” Fujioka said.
He and his colleagues presented their findings during the 228th national meeting of the American Chemical Society in Philadelphia.
Revision date: June 22, 2011
Last revised: by Janet A. Staessen, MD, PhD