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Grapefruit Diet – Drastic Weight Loss In Just 7 Days?

Published: 13th May 2018. Last updated: 21th July 2019.

Luna Smithton

Editor & Fact Checker


With so many different weight loss diet plans to choose from, finding a one that actually works for you can be a somewhat difficult task.

While most diets simply focus on eliminating certain foods or scaling back your calories in general, there are also diets out there that are focused around specific foods which are claimed to have special weight loss qualities - these diets usually encourage people trying to lose weight to consume large amounts of these foods.

What Is The Grapefruit Diet?

The Grapefruit Diet is a diet that claims a certain food (grapefruit) is the key to losing weight. It is a twelve day diet that promises quick weight loss, as much as 10 pounds in the time period.

The speed of the weight loss has been criticized by health professionals as too quick. Doctors also state that due to the rules of the diet, much of that weight loss will be water and muscle and just a small amount of fat.

Loss of muscle can cause a slowed metabolism that can contribute to weight gain once the diet is stopped so it is important that those following it take measures to prevent this.

The idea behind the Grapefruit diet is that there are fat-burning enzymes found in grapefruit that will help dieters shed weight quickly and easily, while still eating three meals a day and without excessive exercising.

There are no scientific studies to support the claims that grapefruit contains special fat-burning enzymes.

How Does It Work?

The concept is pretty simple, people following the grapefruit diet are told to consume grapefruit or grapefruit juice before or with a low-calorie breakfast, lunch and dinner.

This should be fresh grapefruit although canned grapefruit in its own juice is acceptable if no fresh alternative is available.

As well as eating grapefruit, dieters should follow the food plan. This consists of combinations of foods that are claimed to increase the grapefruit’s fat-burning properties, although there is no scientific evidence for this.

Breakfast foods are dictated exactly, while lunch has to be a salad with unlimited meat and any dressing you like and dinner is again a salad with meat or fish. Followers may also have an 8oz glass of skimmed milk or tomato juice as a bedtime snack.

The calorie-amounts consumed on a typical day are under 1000, although some versions recommend dropping as low as 800 daily calories.

The Grapefruit Diet will very likely help you lose weight provided you stick to the exact directions, however it certainly isn't something you'd want to sustain over a long term period, as it will not provide you will all the vitamins and minerals your body will require.

Strictly speaking, any diet that limits your daily caloric intake works - you should also bare in mind the difficulty of a diet when considering whether or not it'll work for you.

We believe that, for most people, it won't work; it will likely be too difficult to sustain and the lack of essential nutrients in the daily eating plan will probably leave most of those who follow it feeling lethargic and weak.

Other Grapefruit Diet Rules

There are also other rules to follow, including:

  1. Only one cup of tea or coffee is allowed and this must be consumed at dinner time
  2. No soda is allowed (containing sugar or sugar-free)
  3. No other fruit is allowed in the grapefruit diet except one glass of tomato juice as a bedtime snack
  4. Breakfast must consist of two hard boiled eggs and two slices of bacon as well as the grapefruit or grapefruit juice
  5. You may substitute the lunchtime and dinner salads for red or green vegetables cooked in butter
  6. No sugar is allowed and starch is restricted, although if you experience extreme hunger you may have a very small amount of whole grain pasta or cereal.

The Importance Of Water On The Diet

There are many Grapefruit Diet advocates that recommend drinking eight to ten glasses of water a day, as well as the grapefruit juice and tea or coffee at dinner.

This can reduce the feeling of hunger and well as hydrating the body, decreasing the risk of headaches from hunger.

Grapefruit is low in sodium and has a high water content so this assists in ensuring that dieters do not retain excess water weight.

Do You Need To Exercise While Following The Grapefruit Diet?

Exercise is always important while you're on a diet, both for the purposes of supporting fat metabolism and overall longevity. While following the Grapefruit diet, we would only recommend followers introduce some LISS (Low Intensity Steady State) cardio and light weight training into their daily routine - anything high intense would likely not be a great idea.

As the Grapefruit diet plan is extremely low in calories, most dieters will very likely find themselves too fatigued to partake in any sort of strenuous exercise - keeping it slow and steady will make things easier, but may also prevent you from burning out.


This is a fad diet that is not backed by science and any weight loss associated with following the grape fruit diet is due to the extreme calorie deficit and not "special enzymes" within grapefruit.

Yes, grapefruit is a food rich in water and vitamin C, and can be incorporated into a health diet for weight loss or weight maintenance, but the diet does not provide creative solutions or long term guidance for proper nutrition or maintaining a healthy body weight.

On the positive side, the foods suggested within the diet plan are everyday items that require no specialist knowledge of nutrition or cooking, which means the program could be a possible consideration for people wanting to quickly lose weight over a very short period of time.

When dieting, you should also consider your general health - it is certainly not something you should sustain for a long period of time, as it simply doesn't contain enough of the nutrients your body requires to function properly.

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