More than 52 million Americans are actively trying to lose weight. One of the best-selling books of all time, “The Dr. Atkins Diet Revolution,” which has attracted more than 30 million American dieters, allows people to eat as much fat as they want, but very few carbohydrates. Dr. Atkins claims that without carbohydrates and foods loaded with sugar, the body is forced to burn fat for energy, which he says takes off pounds. However, last fall the American Heart Association issued an advisory against going on high-fat diets like Atkins', though the diet has never been tested. What's a dieter to do?