Which is the Best Diet Plan: Atkins, Ornish, Weight Watchers or the Zone Diet?

Low-fat, high-carbohydrate diets had the official U.S. seal of approval since 1979. Low-carbohydrate diets, such as the Atkins diet, were wildly popular in the 1970's and again during the past five years. Well-controlled studies show that people can lose weight on the Atkins (restricts carbohydrate), Ornish (low-fat), Weight Watchers (low-calorie) and Zone (nutrient intake balanced) diets, but which one is best?

A study of 160 people by researchers from Tufts University New England Medical Center showed no difference in weight loss or changes in cardiovascular disease risk factors such as blood pressure, BMI, cholesterol, LDL, HDL, or C-reactive protein between groups assigned to each diet plan for a year. Each of the diets helped people lose a modest amount of weight after one year (four to seven pounds).

Adherence to the diet was equally poor in each of the groups. The study showed that each of the diets was equally effective at 12 months if you stick to the diet plan so find the one you can stay with.

The Science Behind Low-Carb Diets

Low-carbohydrate, high-protein diets are not as popular as they were last year, even though the science supporting them has increased. Low-carb diets force the body to use fats instead of carbohydrates as fuel. The body prefers to use carbohydrates as fuel and save fats for emergencies.

It's easy to store fat, but very difficult to lose it. High-sugar diets stimulate insulin in response to high blood sugar levels. Insulin is essential for transporting sugar into the cells, but it also promotes fat storage. Low-carb diets keep insulin release to a minimum, which increases fat use for energy and in turn, promotes fat loss. Drs. Jeff Volek and Matthew Sharman summarized nearly 10 years of research on low-carbohydrate diets. Compared to traditional low-fat diets, lowcarb diets consistently caused greater improvements in fat loss, blood fats and insulin resistance. More research is needed to assess the long-term effects of these diets.

Weight Loss Similar in Low and High-Carb Dieters

Most studies show that people lose more weight in six months on low-carbohydrate (LC) than low-fat diets (LF). Critics say people consume fewer calories on LC diets, which accounts for their success. Researchers from the Albert Einstein College of Medicine found that subjects lost the same amount of weight on low-carb and low-fat diets when they consumed the same number of calories and protein. The study showed that people lose more weight on low-carbohydrate diets because they eat less.

Protein and ketones (produced during low-carb diets) suppress appetite and decrease caloric intake. This study examined only four subjects, so the results are just preliminary.