Can certain foods actually encourage your body to break down fat and discourage the deposition of additional fat? Possibly.
Grapefruit has been regarded as a health food and a diet aid for many years, but it is only recently that evidence of grapefruit’s metabolism and interaction with the human gut is shedding light on the mechanisms involved. And it may actually prove to be a useful adjunct to diet and exercise in the battle of the bulge.
In a study done at the Scripps Clinic in La Jolla, CA in 2006, it was shown that patients randomized to 1/2 a fresh grapefruit (or 8 ounces of grapefruit juice) three times a day before each meal lost more weight than the placebo group and there was a significant reduction in insulin levels after food intake. Insulin is a hormone which regulates carbohydrate and fat metabolism–and encourages the storage of fat while simultaneously preventing the breakdown of stored fat. If an individual’s goal is to lose weight (and fat), it would be advantageous to prevent any surges in insulin release. In addition, grapefruit has been investigated as a prebiotic–defined as an undigested food ingredient which encourages the growth of beneficial bacteria within the gut. This relationship is quite complex and still under investigation, but evidence thus far suggests that the undigestible sugars in grapefruit (fructooligosaccharides, FOS) support the growth of Bifidobacterium and Lactobacillus species in the gut–both which confer numerous health benefits to be discussed in PROBIOTICS post.
Other than the above mentioned advantages of regular grapefruit ingestion, grapefruit contains powerful antioxidants (eg. lycopene) and vitamin C , has been shown to improve lipid profiles, lower blood pressure in people with hypertension and reduced the risk of kidney stones (Calcium oxalate type).
CAUTION: Grapefruit and grapefruit juice are known to interact with many drugs such as blood pressure medications, statins, anti-arrhythmics, anxiolytics, antidepressants, and protease inhibitors (discuss this with your prescribing doctor; for a more complete list see https://secure.pharmacytimes.com/lessons/200303-02.asp). In addition, in large quantities, the components of grapefruit can have the opposite effect than that intended (e.g. with regard to gut flora). Remember: Poison is in everything, and no thing is without poison. The dosage makes it either a poison or a remedy. ~ Paracelsus
BOTTOM LINE: In moderation (and in the absense of drug interactions), grapefruit may help with weight loss/ weight control, particularly if added to a calorie restricted diet and regular exercise. I personally love to eat grapefruit and try to incorporate it into our meals daily.