Why Some Doctors Warn Against The Grapefruit Diet

Among the list of fad diets — one that gains popularity within a short time — the grapefruit diet is one of the oldest. According to Cleveland Clinic, the diet first emerged in the 1930s, making claims that it would help people rapidly shed pounds.

Surprisingly, a lot of people still follow the said diet, probably because it promises to help them lose weight within a very few days. As the name suggests, a person has to consume plenty of grapefruits when following this particular diet. The website explains that the unique selling point of the diet is that followers could shed up to 10 pounds within 10 to 12 days through the process of detox.

The grapefruit diet became more popular after several celebrities, including American actress Brooke Shields and Australian singer Kylie Minogue, endorsed it (via The Daily Mail). And as explained by Healthy Celebs, due to such endorsements, the diet also earned the name "Hollywood Diet".

Per Cleveland Clinic, while there are several variations of the diet, most of them involve the consumption of half a grapefruit before each meal. Alternatively, one can have about 8 ounces of grapefruit juice without adding any sugar to it. But it isn't just about the consumption of the fruit; one also has to drastically restrict their daily calorie intake for the diet to be effective.

According to the website, some of the plans suggest users consume as little as 800 calories per day when following the grapefruit diet. Other things that can be eaten during the grapefruit diet include salads, leafy green or red vegetables, meat cooked in the desired manner, and a cup of tea or coffee without the addition of milk or sugar. 

One cannot have snacks in between meals, and some variations of the diet also allow followers to drink a glass of skim milk or tomato juice before going to bed (via Very Well Fit).

While some celebrities swear by the effectiveness of the grapefruit diet, doctors warn against it because of several reasons. First, consuming 800 calories a day is not good for your health. For adult women, the calorie intake should not fall below 1,200 a day, while men should consume at least 1,500 calories a day (via Harvard Health Publishing). Moreover, grapefruit can dangerously interact with certain medications.

As pointed out by Very Well Fit, there are 50 common drugs that can interact with grapefruits. These include thyroid medications, anti-depressants, and statin medications, which are used to treat high cholesterol, among others.

According to Shiew Mei Huang, Ph.D., of the U.S. Food and Drug Administration (FDA), grapefruit juice, after interacting with certain medications, will allow more of the drug to enter the blood. "When there is too much drug in the blood, you may have more side effects," she said.