Losing 50 pounds of weight is a great accomplishment. Regaining 75 pounds is a greater disappointment. Just ask anyone who has lived through the nightmare. Some have lived through the nightmare more than once. This type of yo-yo weight loss and regain is also bad for your health.
Researchers at the University of California at Los Angeles analyzed 31 long-term diet studies and found that about two-thirds of dieters regained more weight within four or five years than they initially lost.
So what are the causes of massive weight loss and regain? In my experience, severe calorie restriction is at the top of the list. We are bombarded with commercials like, “lose 30 pounds in 20 days.” This is a short-term solution to your long-term weight problem.
A study reported in the Journal Of Obesity found that people who followed a very low-calorie diet regained significantly more weight than those on a more forgiving plan. Desperate for quick results in a culture of instant gratification, "women try to lose weight on diets with too few calories," said Judith Beck, Ph.D., director of the Beck Institute of Cognitive Therapy and author of The Beck Diet Solution. "If you lose weight on 1,200 calories a day, the minute you go up to 1,300 is the minute you start gaining weight." My experience has shown me that women will increase calories to much more than 1,300 calories.
Severe calorie restriction also causes your metabolism to slow down because your body thinks it is starving. So, it stores fat as a survival mechanism. Prolonged severe calorie restriction also weakens your immune system, creates hormonal imbalances, agitates the nervous system, generates loss of muscle mass, increases body fat, decreases energy levels and disrupts sleep patterns.
According to Kelly Brownell, M.D., director of the Rudd Center for Food Policy and Obesity at Yale University, "The body may perceive dieting as a threat to its survival. It might not know the difference between Atkins and famine."
What's more, said Brownell, who coined the term "yo-yo dieting" in the 1980s, weight cycling can actually change your physiology.