If you are starting out 2013 by trying to lose weight, you are probably interested in finding the “best” diet. Since most of your weight loss will come from changing your eating habits, the right diet can improve your chances for success. In reality, there is no single best diet for everyone. An effective diet should meet two important goals: to reduce calories and to promote sustainable, healthy eating habits. With this in mind, the best diet for you will help you make long-term lifestyle changes to promote losing weight and keeping it off, hopefully forever.

What to look for in a diet

In general, a weight loss diet should: 1. reduce calorie, fat, and sugar intake; 2. emphasize whole grains, fruits, vegetables, low-fat protein sources; 3. incorporate “real” food and teach healthy choices; 4. reduce portion sizes; and 5. include regular exercise. The last two are particularly important since cutting back on portion sizes almost always reduces calories and daily exercise will increase weight loss and help you keep it off.

You should also look for a diet or weight loss program that includes some type of support. Weight loss programs that include a group dynamic, like Weight Watchers, may be beneficial. Many people find that the group support and being accountable to others improves their adherence and success. Less formal groups in the workplace or through community organizations (YMCA Team Lean, for example) can also be effective. Some programs offer support, information, and tracking online or through mobile apps.

The goal of a good diet should be for you to learn how to change your lifestyle for long-term weight maintenance, not just short-term weight loss. The result may be losing weight more slowly, but you are less likely to gain it back.

What to avoid in a diet

Diets and weight loss programs should not: 1. restrict or overemphasize specific foods or nutrients; 2. severely limit calories (less than 1,000 calories per day); or 3. require you to purchase special meals or supplements. Be wary of diets that instruct you not to eat foods that are generally recognized as healthy, like fruits and vegetables, or those that rely heavily on prepackaged meals. If you eat mostly ready-made foods you are missing out on an opportunity to learn how to select foods and prepare meals. These meals, snacks, and supplements are usually included to increase profits, and are not necessary for long-term success. Severe caloric restriction can cause rapid weight loss, but most of it is quickly regained.

Keep in mind that there are no dietary supplements that have been shown to be effective for promoting weight loss, despite what the manufacturers claim. In fact, some could even be dangerous. Be especially skeptical of claims that a supplement can burn fat without changing your diet or exercising and know that words like “flush” and “cleanse” are meaningless.

There are a few prescription medications and one over-the-counter drug (Orlistat) that has been shown to promote weight loss—but only when combined with a healthy low-calorie diet and exercise.

Picking a diet that you will follow is an important first step in losing weight. Since your goal should be to lose weight and keep it off, a diet that teaches you to prepare and choose healthy foods and includes daily exercise is essential.

Next week I will share more advice about making lifestyle changes that will help you achieve long-term success. In the meantime, you can learn more weight loss and exercise tips, included a recommended diet, at my blog: http://drbrianparr.wordpress.com/

Brian Parr, Ph.D., is an associate professor in the Department of Exercise and Sports Science at USC Aiken where he teaches courses in exercise physiology, nutrition and health behavior.