Here's what it says:
In a small study published in the Oct. 27 issue of the New England Journal of Medicine, Australian scientists found that after overweight and obese patients followed a low-calorie diet for 10 weeks, their appetite and hunger hormone levels changed. While some hormone levels increased and others went down compared to before they dieted, nearly all of the changes favored the body's efforts to regain the lost weight.It's studies like these that I think demonstrate the most clearly why crash diets don't work. Your body just responds by doing everything it can to put back on any weight you lost.
The scientists used blood tests to measure levels of nine different hormones at the start of the study, at week 10 when the diet period ended, and again a year later.
The hormone levels did not revert to baseline values within 12 months after the initial weight reduction, said study senior author Dr. Joseph Proietto, a University of Melbourne professor of medicine at Austin Health in Victoria.
For example, in follow-up blood tests, one hormone called ghrelin, an appetite stimulator produced by cells in the lining of the stomach, increased after weight loss and continued to do so throughout the study. On the other hand, levels of the hormone leptin, which suppresses appetite, went down.
Making gradual permanent changes to your diet--in the direction of eating less processed food, less meat and more fruits and vegetables--leads to longer term weight loss. It may take a year to lose 20 pounds, but the 20 pounds that comes off, stays off.
Call it the Tortoise diet. The Hare may take off weight faster, but it's the tortoise that keeps it off.