Many popular fad diet plans recommend fasting or eating little except cabbage soup, juice, or some other liquid for several days as a way to jump-start weight loss. But do they work?

Hardly, and here’s why. Not so very long ago, humans lived in a feast-or-famine world. Food was difficult to come by and sometimes was not available at all. To ensure survival, the human body coped with these cycles by going into starvation mode when calories were few and far between.

Fast forward to today, where many people try and fail to lose weight because they cut calories and inadvertently trigger this ancient survival mode. The body responds to a cut in calories by lowering metabolism, burning muscle instead of fat, hunkering down to preserve all the fat storage it can, and converting the few calories that do come in into more fat stores in case the famine will be a prolonged one.

When someone starts a fast, they may indeed drop a number of pounds very quickly, but the weight loss is most likely in the form of water and muscle, which is exactly the opposite of the long-term goal of losing fat.

Of course, nobody can subsist on such limited calories for long, and as soon as one gives up on the fast and goes back to regular eating, his or her now slower metabolism makes burning those calories that much harder. At the same time, body fat stores have increased, and muscle stores (which are what fuels metabolism) have decreased, leaving the person in a worse position than before the fast.

Fasting can also send cravings and hunger through the roof, as the brain sends out the signal that the top priority is to find food, preferably high-calorie food, at all costs. Bingeing is often the result.

Like a snowball going downhill, the more times the cycle is repeated, the quicker the momentum builds and the weight lost during fasting quickly returns, and then some. Without realizing it these people on fasting diet plans are setting themselves up for long-term weight gain, not weight loss!

It’s true that some patients on The Center for Medical Weight Loss plan do follow a liquid diet initially, but it is a far cry from fasting. The liquid diet is nutritionally balanced and high in protein, unlike cabbage soup or fruit juice. Even though calories are reduced drastically, the body does not perceive it as a famine because its nutritional needs are being met.

On such a plan it is possible to drop weight as quickly as with a fasting diet, but without triggering the starvation mode and subsequent slower metabolism, muscle loss, fat gain, out-of-control cravings, and rebound weight gain as soon as one tries to eat normally once again.

So instead of trying to lose weight by going on a fast or fad diet on your own, give the scientifically based medical weight loss approach a try. We can promise that not only will you lose the unwanted weight quickly, but you’ll also put an end to the yo-yo dieting cycle for good. Best of all, you’ll also have help, support, and encouragement every step of the way.