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.