"But you have to know where sugars come from and eat nutritious meals," says Dr. Freedland. "Patients will tell me that they've given up red meat in favor of fish. Turns out, they are abstaining from grass-fed beef, which is reasonably healthy, and are now eating tilapia, which is anything but healthy. And they're eating fat-free ice cream, which is chock-full of sugar. We've been fat-phobic in the United States for 30 years. I wouldn't tell people to eat all the fat that they want. But when it comes to fighting obesity, sugar is public enemy number one."

That means avoiding the hidden sugars in white rice, pasta, and white bread. Giving up sodas is great, but it's not enough if you're still eating the sugars in carbohydrates such as french fries, cookies, and candy bars. "Even your basic baked potato has a lot of carbs," Dr. Freedland adds. "Many people can scale back on sugar at breakfast, lunch, and dinner, but when they want a snack, they grab that piece of candy. We encourage a handful of nuts or vegetables instead."

