The amount of weight you lose on a juice fast depends on a number of factors, including how many total calories you take in from the juice, your physical activity level, how long you remain on the diet, and your resting metabolic rate. On a juice fast, you get all of your calories from juice. Dieters follow this plan for a short period, such as three days, and not usually more than seven. Because you get your calories from drinking juice only, your calorie intake drops, and you lose weight. However, this is not a long-term weight loss solution, and it's considered a fad diet.
Weight Loss on a Juice Fast
Juice fasts often promise rapid weight loss, and it's true: You may lose as much as 1 pound per day during your fast. The truth is, though, due to the short-duration and low nutrients, the weight you lose while juice fasting is mostly water and lean mass, not fat.
This means juice fasting is not a good weight-loss strategy. It contains too little calories, much lower than very-low-calorie diets, which causes your metabolism to slow in an effort to conserve energy -- meant to help you survive during food scarcity. Once you return to your normal eating habits, you'll almost certainly regain the weight you lost and maybe even more. A juice fasting diet contains zero fiber, a nutrient essential to your digestive health. In addition, because of the absence of fiber and excess of fruit sugar you're taking in through the juice, you may experience digestive discomfort.
A juice fast provides inadequate protein, a nutrient essential to preserving lean muscle when cutting calories. Without enough protein to maintain your lean mass, the body breaks down much more muscle for energy than fat. This leaves you with a less favorable body composition after you've done a juice fast, since a significant amount of the weight that you do lose will consist of muscle.
Eat This Instead of Juice Fasting
People interested in juice fasting typically have a small amount of weight to lose, such as 10 pounds. It's easy to mistakenly believe juice fasting will get you the quick 10-pound weight loss you're looking for; however, instead of depriving your body of essential nutrients, slowing your metabolism and sacrificing lean muscle through a juice fast, make sensible changes to reduce your calorie intake so you can lose weight and keep it off.
Maintaining a healthy weight is about consistently making nutritious food choices. Look for areas in your diet where you can choose nutrient-packed options. Focus on whole foods including lean meat, fish, poultry, eggs, beans and other legumes, fruits, vegetables and whole grains. Make easy swaps like grilled chicken instead of fried and mixed nuts instead of crackers. Use olive oil in place of butter, swap out white potatoes with sweet potatoes, and have brown rice instead of white.
Beware of Health Food Fake Outs
If you think you've been eating healthy, check for impostors in your diet. Some foods are marketed as health foods that may add extra calories and sabotage your weight loss. Swapping the impostors out for real whole foods is a good way to reduce your calorie intake.
A few of the most common impostors are breakfast bars, frozen yogurt, store-bought smoothies and diet soda. Most breakfast bars are high in sugar and fat, and some health authorities, such as England's Department of Health, feel these bars shouldn't have a healthy image. Cereal bars are also less satisfying due to a higher-calorie density, which refers to the amount of calories per serving size of food.
Frozen yogurt and smoothies are two other common offenders. On the surface, frozen yogurt may seem like a healthier option compared to ice cream, and smoothies may seem like a nutrient-packed morning boost, but this is often not the case. Frozen yogurts often contain more sugar that ice cream and store-bought smoothies are typically high in sugar as well.
Diet soda is another fake. The artificial sweeteners in diet soda fail to trigger brain signals that promote feelings of fullness, potentially causing you to eat more. When compared to regular sugar, the typical artificial sweetener increased hunger, according to a review in the Yale Journal of Biology and Medicine, published in June 2010.
Get Hands On and Homemade
The best way to cut calories in your diet is to make your meals yourself. While it's easy to grab a breakfast bar, it's much more nutritious to have 1/2 cup of whole oats with a 1/4 cup of blueberries and a dash of soy milk. It's convenient to snag a shop-bought smoothie, but much better to make one at home using plain yogurt, soy milk and 1/2 cup of your favorite fruit. If you normally have diet soda, make homemade fruit-infused flavored water by immersing chopped fruit into a pitcher of water. When you want frozen yogurt, make it yourself by blending and freezing plain yogurt, soy milk and fruit.
- Yale Journal of Biology and Medicine: Gain Weight by “going Diet?” Artificial Sweeteners and the Neurobiology of Sugar Cravings
- Family Doctor: How to Make Healthy Food Choices
- NHS Choices: Cereal Bars Don't Deserve 'Healthy Image'
- CNN: The Real Scoop: Frozen Yogurt Only Sounds Healthier than Ice Cream