f everyone in the United States simply adopted the U.S. Dietary Guidelines of 2005 (http://www. cnpp.usda.gov/GAs2005Guidelines .htm), obesity would be on its way out. Exercising 30-90 minutes a day, eating at least half of our grains as whole grains, and eating four servings of fruits and five servings of vegetables 'a day are simple prac­ tices that are advised because of their ability to improve energy bal­ ance, keeping us from gaining weight and helping us to lose weight if we need to.