You may use a juice fast as a detox diet or for short-term weight loss, but in the end, a juice fast does not lead to healthy fat loss. Much of the weight you'll lose on a juice fast will be water weight -- and quickly regained when you resume your normal eating habits. Beware of fad diets that promise unrealistic results -- if you can lose 10 lbs. in a week, its not fat you're losing.
Talk to your doctor before beginning any type of juice fast or detox diet.
There is very little medical evidence that a juice fast can help detox your body. Your lungs, skin, kidneys and liver are your built-in detoxification system that filter waste and eliminate any compounds your body doesn't need. Juice fasts and cleanses may rob your body of vital nutrients, weaken your immune system, upset your electrolyte balance and flush beneficial bacteria from your digestive tract. One of the side-effects of a juice fast is weight-loss; but the drastic reduction in calories, lack of protein and liquid-only nature of the diet won't help you lose fat.
True weight loss really refers to losing stored body fat. Your body fat percentage may be a better indicator of your health and risk of obesity-related disease than your overall weight. Losing body fat takes time. The Weight-control Information Network says that you can't lose more than 2 or 3 lbs. of body fat per week. If you lose weight faster than that, you may be losing water weight or lean muscle mass. Losing muscle mass is not good and slows your metabolism; at rest, muscle tissue uses more energy than fat.
Calories, Energy and Metabolism
A juice fast is low in calories -- and calories are what your body uses for energy. When you need more energy, your body can either break down stored fat or convert lean muscle into energy, forcing your body to use stored energy. Ideally, you'll break-down triglycerides in your fat cells and covert them to energy. But if you don't consume the minimum number of calories to keep your metabolism functioning, your body will find it easier to convert muscle tissue rather than fat to energy -- especially in the absence of protein. If you eat protein when you reduce your caloric intake, your body won't cannibalize lean muscle tissue. The American College of Sports Medicine recommends that women eat at least 1,200 calories each day -- 20 percent of those calories should come from protein.
Healthy Fat Loss
Healthy fat loss comes from making diet and lifestyle changes that you can sustain long-term. Eat a variety of foods, limit added sugars and foods high in empty calories, watch your portion sizes and add regular exercise into your daily routine. Stay away from fad diets that eliminate entire food groups and aren't nutritionally safe. Because a juice fast could potentially slow your metabolism, it may be easier to gain weight once you've finished your cleanse. Set realistic weight-loss goals and remember that your overall health is more important than the number on the scale.