Does Grapefruit Juice Break Down Fat?

Grapefruits produce a tangy citrus juice that people often enjoy as part of a balanced breakfast. A cup of canned, unsweetened white grapefruit juice only contains 38 calories, according to the United States Department of Agriculture. This low-calorie drink is the focus of many weight-loss hypes. However, insufficient scientific research exists to prove that grapefruit juice has the ability to break down fat or aid in weight loss.

Fat Breakdown

Your body breaks down fat for energy when you consume fewer calories than you expend. Both diet and exercise levels play a role in making this happen. Grapefruit juice may decrease your calorie intake and cause your body to break down fat if you use it in place of higher calorie drinks or foods. However, if you start drinking grapefruit juice, but fail to decrease your calorie intake by making other changes to your diet, or fail to increase the number of calories you burn through exercise, weight loss or fat breakdown typically will not occur, explains Karen Collins, a nutritionist and registered dietitian in Jamestown, New York.

Research

Very few published studies have looked at the relationship between grapefruit juice and weight loss. A study published in the spring 2006 issue of the "Journal of Medicinal Food" found that participants who consumed fresh grapefruit, grapefruit juice or a grapefruit capsule before meals lost more weight than participants who took a placebo. This study also showed improved blood glucose levels in the group that consumed the grapefruit. However, the researchers concluded that the exact mechanism for weight loss remains unknown.

Analysis

One study does not prove the effectiveness of grapefruit or grapefruit juice as a weight loss or fat burning aid. Collins explains that the study in the "Journal of Medicinal Food" failed to prove that grapefruit, in any form, increased fat breakdown or caloric burn. The study did indicate that the acid content in grapefruit might cause the stomach to empty slower. This could result in decreased feeling of hunger and steadier blood sugar levels, which help in weight loss and calorie reduction. If drinking an 8 oz. glass of grapefruit juice before each meal causes you to consume fewer calories throughout the day, your body will break down more fat for energy than it normally would, according to Collins.

Fat Loss Advice

The Weight-Control Information Network advises that no food, including grapefruit juice, breaks down fat or speeds up your metabolism fast enough to cause weight loss. However, grapefruit juice does provide a serving of fruit that you can incorporate into a healthy, weight-loss diet that emphasizes fruits, whole grains, reduced-fat dairy, vegetables, legumes, nuts, fish, eggs and seeds.

Precaution

Grapefruit and grapefruit juice can cause dangerous interactions with some medications, even days after consumption, warns the Family Doctor website. Consult your doctor before adding grapefruit to you diet if you take medication for high cholesterol, heart arrhythmia, high blood pressure, depression or HIV.