Fasting is an age-old practice, often done for religious reasons, but fasting for weight loss is still capturing the public imagination. You can find dozens of do-it-yourself plans touting the unproven benefits of fasting, ranging from flushing "poisons" from the body to purging 30 pounds of fat in 30 days.
Typical Fasting Weight Loss Plans
Fasting regimens vary, but the basic premise usually starts with a strict regimen allowing only water, juice and/or some kind of laxative concoction. Some plans allow a few solid foods, but are still called fasts because they provide so few calories.
Not all fasts are created equal. Some can be perfectly safe, such as medical fasts supervised by a physician. Religious and cultural fasts are typically undertaken as an act of devotion, last from 24-48 hours, and are not intended to promote weight loss.
Dangers of Fasting for Weight Loss
When you dramatically reduce your calorie intake, you will lose weight. But it can also cause all kinds of health problems, including muscle loss. Further, when you start fasting, your body goes into conservation mode, burning calories more slowly.
Keep in mind that the initial weight lost on a fast is primarily fluid or "water weight," not fat. And when you go back to eating, any lost weight usually gets a return ticket back. Not only do most people regain weight lost on a fast, they tend to add a few extra pounds because a slower metabolism makes it easier to gain weight. Worse, the weight that is regained is likely to be all fat -- lost muscle has to be added back at the gym.
Effects of Fasting on the Body
Alternate Day Fast
The 5:2 Diet