The Grapefruit Juice Diet – What’s It All About?

grapefruit juice

An overview of the grapefruit juice diet

This grapefruit juice diet is far from new, but interest is building and I often get asked about it.  I hope you’ll find the information below both helpful and interesting.

At its heart, this diet is a short-term program that’s intended to promote quick weight loss.  For unknown reasons, it’s sometimes called the “Mayo Clinic Diet” – it has no known connection with that renowned healthcare facility.


There are several different versions, although they all focus on grapefruit and grapefruit juice.  Most involve a 12-day on and 2-day off regimen, but 7- and 21-day programs are also out there.  Many versions claim to deliver at least a 10-pound weight loss over the program’s length.


Please Note:  As with any diet (especially the quick weight-loss types), it’s important to check with your physician before you begin.  Abundant research has shown that grapefruit interacts with a number of medications, and in some cases potentially serious side effects can occur.  According to these studies, grapefruit inhibits an intestinal enzyme that normally helps your body break down and absorb these medications.  When grapefruit (or another substance) blocks this enzyme, the amount of these medications in your blood might build to a potentially dangerous level.  Don’t be scared of grapefruit though, this diet just has so much of it in the program that you should know this.


Grapefruit's role

Proponents of the grapefruit juice diet believe the fruit is a food that’s capable of melting off excess body fat naturally because it contains a fat-burning enzyme.  Recent research at San Diego’s Scripps Clinic indicates that adding grapefruit or its juice to your diet helps with weight loss and lowers blood insulin levels – a result that could lower your risk of developing diabetes.  By incorporating grapefruit juice into all of your meals, you’ll be helping your body eliminate your unwanted fat.  The pounds will drop off quickly.

Foods you can and can't eat on this diet

This diet has several versions, but they all involve grapefruit or grapefruit juice at every meal.  The other foods and beverages you’re allowed to consume are restricted to just a few types.  Generally speaking, the grapefruit juice diet allows you to prepare your food in any way you like – fried foods aren’t taboo like they are in many other diets.  Likewise, unlike many other diets, this one lets you indulge in high-fat foods like bacon, mayonnaise, salad dressing and butter.


In fact, foods with a high fat content are essential to the diet.  This low-carb, high-fat diet uses grapefruit’s ability to burn body fat when it’s consumed with foods that are themselves high in fat.  As a result, the grapefruit juice diet features high-fat, high-cholesterol, protein-rich foods such as eggs and all types of meat.


The diet’s typical breakfast consists of 4 ounces of grapefruit juice (or ½ a grapefruit), eggs, and sausage or bacon.  Lunch includes the same amount of grapefruit juice or grapefruit with unlimited meat and salad of any type.  Dinner is another 4 ounces of grapefruit juice or ½ a grapefruit, unlimited meat (or fish), and red, green or yellow veggies, preferably cooked in or served with butter.  Green or red onions (but not white onions), cucumbers, bell peppers, broccoli, radishes, peas, carrots, cabbage, lettuce and spinach are all acceptable.  The typical bedtime snack is a glass of milk or tomato juice.


Carbohydrates are severely restricted.  So, sugar is a big no-no, as are sweetened cereals, grains, bread, potatoes, sweet potatoes, desserts, white onions, celery and naturally sweet fruits and vegetables.  The grapefruit and grapefruit juice themselves must be unsweetened.  Unsweetened coffee and tea are okay in limited amounts, but you should drink at least 8 cups (64 ounces) of water every day.  Foods and beverages not on the diet are not allowed.

As a general rule, you’re encouraged to eat as much as you want at every meal - feel free to help yourself to seconds or even thirds.  Some instructions go so far as to say you should eat until you’re stuffed.  Never skip the high-fat meats and salad dressings - they provide the dietary fat that allows the grapefruit to burn off body fat.  Snacks aren’t permitted until after dinner, but if you eat the specified foods until you’re full, you won’t be hungry in between meals anyway.

The diets goal + pros and cons

The grapefruit juice diet is used by people who want to burn off body fat and drop weight very quickly.  It is not designed to build lean muscle mass or increase your strength or stamina.

Once dismissed by experts as just another fad, recent research has shown that the grapefruit juice diet really can help people lose weight – especially when it’s combined with regular exercise.  The weight loss might not be as quick or substantial as some proponents claim (“lose 10 pounds in 10 days!”) but it is measurable.  Grapefruit also has insulin-reducing properties which provide three benefits:


  • High insulin levels can interfere with the body’s ability to break down and burn off fat.  Fat will melt off easier when your insulin level is lower.
  •  High insulin levels can make you feel hungry.  You’ll be less tempted to overeat if your blood insulin level is lower.
  •  Lowering your insulin levels may reduce your risk of developing diabetes.


However, stay away from ultra-low calorie versions of the diet (anything below 1,100 or so calories per day).  Those versions can be dangerous because they don’t provide enough daily calories for your body to function properly. 


You should also be wary of any program that asks you to eat a severely restricted, imbalanced diet for more than a few days at a time.  Although grapefruit juice is a superb source of Vitamin C and fiber, your body needs more nutrients than it and high-fat foods can provide.


Finally, there are indications that the grapefruit juice diet only achieves a short-term weight loss.  In other words, the weight you lose might be mostly fluid and easily gained back once the diet program is over.  A sensible, balanced, calorie-controlled but nutritionally complete diet is much healthier and more effective in the long run. And don’t forget the exercise! While I do believe the grapefruit assists in weight loss, I’m not so sure I would do it :)

Return from Grapefruit Juice Diet to Juicing for Weight loss


Lovin' this juicy info? Leave a comment in the box below


Sign up to get free insider juicing secrets - for radical health and beauty through a straw.

You'll also get 10 tasty juices you need to know now, instantly.

"I've been juicing with Vanessa for the past 4 months and I lost 26 pounds. Feeling great!"



Hi Juice Lover!  I'm Vanessa, the Juicing Mixologist. I'll be guiding you to radical wellness and hotness you can chug. Learn more 


My favorite must-have wellness gadgets

Why the Vitamix is the best blender

Lose weight by juicing

Find top juicers that fit your style

The Green Beauty Juice recipe

Fasting to heal and cleanse

How to make green drinks that taste good

The difference between juicing and blending

The need to know steps on how to start juicing

New to juicing?
Juicing books + guides
Juice Club