The number of calories you need to maintain or lose weight depends on a number of factors, including your age, sex, height, and level of physical activity, according to the FDA. To maintain a healthy body weight, the FDA recommends that you balance the number of calories you consume with the number of calories you burn through physical activity and your body’s metabolic processes. As a rule of thumb, the FDA recommends a standard 2,000 calorie diet for the average adult.
The TLC approach, contained in the 80-page manual “Your Guide to Lowering Your Cholesterol with TLC,” recommends less than 7% of daily calories from saturated fat, less than 200mg of cholesterol, 30 minutes of daily exercise, and drug treatment when necessary. However, critics of the low-fat plan point to its shunning of healthy high-fat plants and its ignoring of the fact that it's calories, and not fat, what determines whether or not a person loses weight.
If you’ve been eating fast food for years, get real about your approach: You’re probably not going to stick to an organic, gluten-free, paleo overhaul for very long. "You want to change as little as possible to create calorie deficit," says Dr. Seltzer, who insists the best way to support sustainable weight loss is to incorporate small changes into existing habits. So instead of giving up your daily BLT bagels in favor of an egg-white wrap, try ordering your sandwich on a lighter English muffin. Or say you eat a snack bar every afternoon: Swap your 300-calorie bar for a 150-calorie alternative. "Your brain will feel the same way about it, so you won’t feel deprived," he says.