Image for popular diets articleWhat is the best diet to help you lose weight and improve heart health in the short-term?

a) a low-carbohydrate (carb), high-protein diet

b) a moderate-carb, high-protein diet

c) a moderate-fat diet

If you chose a, b, or c, you’re right—sort of. The best answer isn’t there. It’s "d"—the reduced-calorie diet that you'll stick with. Why? Because according to a study presented at the American Heart Association (AMA) Scientific Session that compared four different diets, ranging from low-fat to high-protein, all the diets resulted in the same amount of weight loss after one year. A 2009 study by researchers at Harvard School of Public Health found similar results. The important factor is not the nutrients (like a low-fat or low-carb diet), but the caloric intake. According to these studies, if you reduce the number of calories that you consume, then you will lose weight, irrespective of what form those calories take.

Returning to the multiple-choice question, it says “short-term” because the AMA study also found that heart risk scores—which are based on findings from the Framingham Heart study and include total and LDL cholesterol levels—improved with all the diets. For long-term health, in addition to an eating plan that you can realistically follow on a daily basis, there are several factors that will to help keep your weight within your ideal range and keep all your body systems healthy. These factors include regular exercise, relaxation techniques, not drinking to excess, and above all, not smoking.

The truth is, most diet plans are built on the premise that reducing calorie intake leads to weight loss. That means that the diet that’s right for you is the one that limits the foods you are most likely to overeat, but still allows you to eat foods you enjoy.

To help you choose the eating plan that’s right for you, here is a brief explanation of four popular diet plans.

The Atkins’ Nutritional Approach

Atkins’ Nutritional Approach stresses dramatically reducing your intake of carbohydrates and replacing them with foods rich in protein and fat. The theory goes like this: “Your body burns carbohydrates and fat for energy. With Atkins’ unique approach, you limit carbs so your body burns fat.”

What’s Involved

The Atkins’ diet has four phases. During the induction phase, you eat no more than 20 grams of carbohydrates per day, mostly from salad greens and other acceptable vegetables. This means no bread, pasta, rice, fruit, milk, yogurt, cereal, juice, cookies, sweets, or potatoes, among other foods. However, you can eat as much as you like from foods that are pure protein and fat, such as meats, eggs, oils, and butter. The induction phase lasts at least two weeks, and usually results in rapid weight loss.

During the next three phases (ongoing weight loss, pre-maintenance, and lifetime maintenance), you will slowly reintroduce carbs until your weight loss slows and, when you reach your goal, stops. Then, you’ll monitor your weight, and if you gain, you take away carbs again until you lose the weight again. This means that your calorie intake (and your weight) is moderated by adjusting your carbohydrate intake. Protein and fat are not restricted. You are also advised to take a multivitamin and drink eight 8-ounce glasses of water each day.

The Research

A study in the May 22, 2003 issue of the New England Journal of Medicine , reported that people following the Atkins’ diet lost more weight than a control group after three and six months, but that both groups had lost approximately the same amount of weight after one year. This is the typical pattern in studies including the Atkins’ diet—quick weight loss, followed by some regain.

The Concerns

The Atkins’ diet is rich in high-protein and high-fat foods, such as bacon, steak, and cheese. While this eating pattern hasn’t been shown to be harmful when followed for one year, many nutrition experts worry that the high levels of saturated and trans fats as well as cholesterol in these foods will increase your risk for heart attack if you follow the diet for an extended period of time. There is also concern that the high levels of protein can overload and damage the kidneys, which is especially dangerous for people with diabetes or kidney disease.

Dr. Phil’s Ultimate Weight Solution: The 7 Keys To Weight Loss Freedom

Dr. Phil’s focus is broader than most fad diets. He begins with the contention that “If you are overweight, you are out of control.” Then, drawing on his specialty in psychology, he outlines the seven keys to taking control of your thought process, environment, eating, exercise habits, and other aspects of your life that contribute to being overweight. This program seems to target people who have a lot of weight to lose, but most people will benefit from the practical advice.

What’s Involved

Dr. Phil’s nutrition advice is not new, just packaged in a new way. His recommendations are similar to those in the Dietary Guidelines for Americans and the Food Guide Pyramid —balance across the food groups, with an emphasis on fruits and vegetables, whole-grain carbohydrates, lean protein sources, and low-fat dairy products. He also provides tips on portion control and reinforces the idea that no food is inherently good or bad, but that some should be eaten more often than others. Dr. Phil stresses rebuilding self-esteem, setting realistic goals, making changes that will last a lifetime, and allowing yourself some flexibility with those goals and changes.

The Research

Dr. Phil refers to his own clinical practice and research as well as nutrition research in general, but does not discuss specific studies. His “7 keys” plan has not been tested in randomized studies. However, he has begun a weight loss challenge consisting of 13 people who are following his program.

The Concerns

Dr. Phil’s recipe for success requires that people take responsibility for their weight, dredge up the issues contributing to their being overweight, and overcome them. Some people may be empowered by these strategies, but others may be turned off by these “get real” methods.

Weight Watchers FlexPoints Plan

Like Dr. Phil’s program, the Weight Watchers FlexPoints Plan stresses better food choices and portion control for long-term weight loss. The claim is: “With FlexPoints, you can eat the foods you love and still achieve your weight-loss goals.”

What’s Involved

On the FlexPoints Plan, you are allotted a daily POINTS range based on your body weight. Every food has a POINTS value (for example, a scoop of ice cream has about four POINTS and an apple has about one POINT). You can eat whatever foods you want, as long as you stay within your daily range. POINTS values are based on the amount of calories, fat, and fiber in a food.

The FlexPoints Plan also emphasizes exercise. When you exercise, you earn Activity POINTS, which can be transferred into Food POINTS.

Weight Watchers recommends an average loss of two pounds a week for safe and sustained weight loss.

The Research

A study in the April 9, 2003 issue of the Journal of the American Medical Association found that people following the Weight Watchers program lost significantly more than those on a self-help, weight-loss program. At the end of one year, the people on the Weight Watchers program lost an average of 9.5 pounds, while the people in the self-help program lost an average of 2.9 pounds. After two years, the Weight Watchers group lost an average of 6.4 pounds and the self-help group lost an average of 0.4 pounds. Again, losing weight, followed by some weight gain, is typical. However, a net weight loss after two years—no matter how much—is desirable.

The Concerns

Overall, the Weight Watchers FlexPoints Plan is a healthful diet. In addition to cutting the amount of calories you consume and encouraging you to exercise, the diet encourages taking a daily multivitamin, drinking lots of water, and eating plenty of fruits, vegetables, and dairy products. But like any diet, the major concern with Weight Watchers is that people won’t stick with it. It takes effort to calculate the POINTS value of every food you eat, and the traditional version of the FlexPoints Plan requires attendance at a weekly meeting.

The South Beach Diet

The South Beach Diet, developed by cardiologist Arthur Agatston, MD, attempts to find a happy medium between low-carb and low-fat diets. It “teaches you to rely on the right carbs and the right fats—the good ones—and enables you to live quite happily without the bad carbs and bad fats.”

What’s Involved

The South Beach Diet has three phases. During the two weeks of Phase 1, breads, rice, potatoes, pasta, baked goods, and even fruit are restricted. You can eat enough meat, chicken, turkey, fish, vegetables, eggs, cheese, nuts, and salads with olive oil dressing to make you feel full.

Phase 2, which you will stay on until you reach your weight-loss goal, is less restrictive. You can add carbs back into your diet, but in moderation. The focus is on whole-grain carbs, but you can now splurge on refined carbs every once in a while.

After you have reached your weight-loss goal, you will enter into Phase 3, “the stage that lasts the rest of your life.” In this phase, you are encouraged to focus on monounsaturated and polyunsaturated fats instead of saturated and trans fats, and whole-grain carbs instead of refined ones.

Although exercise isn’t a main focus of this diet, Dr. Agatston recommends you take a brisk, 20-minute walk each day. Dr. Agatston claims that you will lose 8-13 pounds in Phase 1, and 1-2 pounds per week in Phase 2.

The Research

The South Beach Diet relies on Dr. Agatston’s own research. A randomized clinical trial published in the Archives of Internal Medicine compared the Modified Low Carbohydrate diet (South Beach Diet) with the National Cholesterol Education Program diet. 60 participants were randomized and the study lasted for 12 weeks. Participants in the Modified Low Carbohydrate diet had significantly greater weight loss over 12 weeks. But since the study was small and, more importantly, since Dr. Agatston himself conducted the study, more research is needed to determine whether the South Beach Diet is effective.

The Concerns

While the strengths of this diet are that it focuses on healthful fats and whole grains, Phase 1 is extremely restrictive and may cause many enthusiastic dieters to give up. Also, the promise that you will lose 8-13 pounds during the first two weeks is questionable. Even if it were true, most health professionals recommend no more than a couple of pounds a week for safe, long-term weight loss.