No food has the ability to melt fat, but grapefruit is a welcome addition to weight-loss diets. Making grapefruit, which is low in calories and filling, a regular part of your diet may help your waistline when part of a healthy, reduced-calorie diet. If you're taking any medication, talk to your doctor or pharmacist before adding grapefruit to your diet.
A study published in a 2014 issue of Food and Nutrition Research noted that people who eat grapefruit tend to have a higher-quality diet and get more vitamin C, magnesium, potassium and fiber than people who don't eat grapefruit.
Grapefruits are fat-free, very low in calories and a good source of fiber. While there are some nutritional differences between white and red or pink grapefruit, on average half of a grapefruit has 32 calories, 8 grams of carbs and 1 gram of fiber. Grapefruits are also an excellent source of vitamin C, meeting 57 percent of the daily value in half of a fruit, and red grapefruit in particular is an excellent source of vitamin A, meeting 28 percent of the daily value per half.
Grapefruit and Weight
In addition to a higher-quality diet, that same study in Food and Nutrition Research also noted that women who ate more grapefruit also had a lower body weight and body-mass index, plus a smaller waist circumference.
Clinical studies investigating grapefruit's effect on weight have yielded mixed results. A 2006 study published in the Journal of Medicinal Food compared the effects of whole grapefruit, grapefruit juice, a placebo and apple juice on weight loss in a group of obese adults. The study found that the group eating grapefruit or drinking its juice lost more weight than the group taking the placebo or drinking the apple juice.
A clinical study published in a 2012 issue of Metabolism also investigated the effects of grapefruit on weight loss in a group of obese people. While the researchers noted a modest reduction in weight in the group consuming the grapefruit compared to the control, they concluded that grapefruit does not significantly reduce body weight.
What Melts Fat
While grapefruit shows some promise in weight loss, you may not want to rely on it alone to help you lose those unwanted pounds. To lose weight and burn fat, you need to create a negative calorie balance, which means eating fewer calories, burning more calories with exercise or a combination of both.
A daily 500-calorie negative calorie balance should help you lose 1 pound of fat a week, according to FamilyDoctor.org.
Grapefruit may help you achieve that negative calorie balance by serving as a low-calorie replacement for higher-calorie foods. For example, if you replace your cup of orange juice in the morning with half a grapefruit, you may save about 90 calories. At snack time, instead of a 1-ounce bag of chips, eat the second half of your grapefruit and save another 120 calories.
Caution With Grapefruit
Unfortunately, grapefruit does not make a healthy addition to everyone's diet. One of the compounds in grapefruit affects how your body absorbs medication, which in turn affects that medication's effectiveness.
Avoid grapefruit and grapefruit juice if you take blood pressure or blood cholesterol medications, immunosuppressants, anti-anxiety medication and some psychiatric medications. Consult with your doctor about your prescriptions and potential food interactions.