Grapefruit Diet Scientific Studies

Grapefruit diet was one of the most popular fad diets of years 1970. At that time, the common belief was that grapefruits contained substances which helped burning the body fat, thus offering a healthy and safe diet, without the so-called yo-yo effect. This meant that once weight lost due to this diet, people won't accumulate back their pounds immediately after stopping the diet.

Yet, time has failed to prove the existence of those fat-burner enzymes in the grapefruit itself or in the grapefruit juice, therefore those persons who managed to lose weight after keeping the grqapefruit diet, got rid of their extra pounds only because they lost fluids accumulated in their bodies. Once the diet ended, fluids were again stored in the organism, thus the body weight increased.

The effects of grapefruit diet on weight loss and appetite

However, there were a few small scale studies undergone by different medical institutions, which aimed to see if there was any connection between weight loss and regular grapefruit consumption.

One of these studies was conducted by Heidi Silver, Ph.D., research assistant professor at Vanderbilt's Center for Human Nutrition, and its main objective was to determine how a diet based on grapefruit or grapefruit juice affects appetite, dietary intake, weight loss and body composition. The research was spread over a two-years period, and it included two phases: Phase 1 - recruiting members and get them to meed nutritionists who made customized diet plans for each of them, and Phase 2 - examination of the correlation between grapefruit and grapefruit juice and appetite variations.

This is how the participants were selected:

To be considered for this study, a prospective candidate must be age 21-50, have a body mass index of 30 to 39.9 (corresponding with NIH classifications for Obesity Class I and II), and must not smoke, drink alcohol or take prescription medications which have a known propensity to interact with certain bioactive compounds found in grapefruit or grapefruit juice.

This is the link to Vanderbilt's Center for Human Nutrition website, where you can read more details about this study. However, it probably hasn't ended yet, as there are no results published at this date.

So, we still have to wait before having scientific proof that the grapefruit diet works.

Grapefruit Diet Overview

Grapefruit Diet Origins

The Grapefruit Diet is a short term weight loss diet which has been known since the 1930s. Originally known as the Hollywood diet, the Grapefruit diet was wrongly attributed to the Mayo Clinic, whose doctors, in reality consider it dis-balanced and dangerous for health. So, if you hear about the Mayo Clinic Grapefruit diet, please be aware that there's no connection between those two, other than the name. Another popular reference is Atkins Grapefruit Diet, called like this because it was based on the Atkins diet principles with a twist (the addition of grapefruit in each meal).

Despite its huge popularity amongst people seeking for fast weight loss plans, schemes or diets, the person who invented the Grapefruit diet is still unknown to this day.

Grapefruit Diet Principle

The main principle of the Grapefruit diet is based on the fact that gapefruits contain a protein or an enzyme which helps burn the body fat, thus leading to a healthy, long-lasting weight loss.
In reality, the existence of this fat-burning substance has never been proven by hard evidences. However, due to the high popularity of this 12 days diet, the doctors did some studies on the relationship between grapefruit consumption and weight loss.

For instance, in the year 2004, a study done by Dr. Ken Fujioka at the Nutrition and Metabolic Research Center at Scripps Clinic, was concluded with the following results: the group of subjects who ate half a grapefruit with each meal lost an average of 3.6 pounds over 12 weeks. Another group, who drank a glass of grapefruit juice with each meal lost 3.3 pounds on average, over 12 weeks. I haven't found more detailed figures, but it seems that many participants in this grapefruit diet study lost more than 10 pounds during the 3 months period of dieting.

The Grapefruit Diet Plan

Originally, the Grapefruit diet was known under a few selling lines such as "grapefruit diet plan lose 10 pounds in 10 days" or "grapefruit diet plan lose 5 pounds in 5 days", and the main by line meant to enhance the motivation of fat people willing to lose weight with this diet was "there might not be any weight loss the first 4 days, but on the 5th day, 5 pounds would be gone".

The main rules of the grapefruit diat were:

1. To eat one half of grapefruit after each meal
2. To eat only three meals a day
3. To refrain from eating snacks between the main meals

This regime is supposed to be respected for either 12 days or 18 days (I've encountered both indications on various fitness and nutrition sources, so I feel like quoting both variants of the diet plan).

Be it that you choose the 12day grapefruit diet or the 18 days grapefruit diet plan, or you simply opt for a grapefruit diet menu, never forget to ask the advice of your physician or of your nutritionist, because he is the only one who knows your body, your diseases, your predispositions, so he is the person entitled to prescribe you a rapid weight loss diet, to set up a daily diet plan tailored especially for your needs, and to indicate whether or not you'd benefit from following for a while the grapefruit diet.