Perhaps you've read Tara Parker-Pope's essay, "The Fat Trap" in the January 1st New York Times Magazine. In the article she asks if you have to be superhuman to lose weight because "...in the battle to lose weight and keep it off, our bodies are fighting against us." She cites several studies and examples demonstrating that weight loss results in metabolic and hormonal changes that conspire to make you regain any weight you've lost.
According to the article hormones like ghrelin and peptide YY are involved with hunger and satiety. When you lose weight they go into reverse so that the body acts as if it was starving. As a result if you've lost weight your body works overtime to regain the weight. So someone who has lost weight and is now 150 pounds will need fewer calories than another person whose weight is 150 pounds without dieting. Research cited indicates that after losing weight muscles burn 20 to 25 percent fewer calories. In addition, brain studies show that after weight loss there's a greater emotional response to food resulting in increased cravings.
In the article Parker-Pope describes her own yo-yo attempts to lose 60 pounds. Despite her failure to lose more than 20 lbs. and the pessimism of the studies she cites, she is "surprisingly optimistic." She doesn't detail the reasons for her optimism but I suspect that understanding the biological reasons for her difficulty in maintaining weight loss is a great relief. Instead of seeing weight gain as a result of a character defect - typically laziness or lack of will power - it is liberating to understand that yo-yoing is a result of hormones and brain function.
Consider your own weight loss attempts. After you've invested all the time, effort and frequently money only to regain the weight (often with a few extra pounds), how did you feel? What happened to your motivation? More than likely you were discouraged and angry with yourself. Eventually you abandoned all efforts to regulate your eating and exercise. If, instead, you recognized that you were fighting an uphill battle, would you have been able to maintain some of the eating and exercising changes you had made?
If you're like Parker-Pope you may not reach your weight loss goals without superhuman effort. Still with doable, modest weight loss you will be able to improve your health risks and feel better. As Parker-Pope points out, losing as little as five percent of your current weight, even if it leaves you significantly overweight, confers significant reductions in health risks. Also, a University of Pennsylvania study demonstrated that weight loss, even if it was considerably less than the original ideal goal, resulted in improvements in self-esteem, assertiveness, and sexual attractiveness.
There are practical implications of the findings Parker-Pope discusses. First, if you are overweight you can be absolved of guilt; some weight loss goals may be unattainable. Instead of being ashamed because of repeated dieting failures you can abandon unrealistic weight loss goals. You can set more reasonable goals and make the lifestyle changes that will enable you to reach and maintain a healthier weight. A new book, The Self-Compassion Diet by Jean Fain can help you accomplish this.
A second implication is that resources should be focused on preventing weight gain by getting children to exercise and have a healthy diet. Preventing weight gain in childhood is much easier than losing weight as an adult and has life-long benefits. If you are concerned about your kids gaining weight, let me recommend my new book, It's NOT Just Baby Fat! (http://amzn.to/g9TAhX) for practical suggestions to help your kids develop healthy eating and exercise habits.