If you've been trying to lose weight for much of your adult life, you're not alone. Excess weight is the No. 1 nutrition problem. The statistics are alarming: Of the ten leading causes of death in the United States, being overweight is a risk factor for half; and the number of Americans who are overweight is increasing. It's estimated that 55 percent (or 97 million) American adults and 15 to 20 percent of American children are overweight today. Dieting...