Is the Zone Diet Healthy?

The Zone Diet is a weight loss plan that focuses on specific proportions of nutrients that allegedly allow for lasting weight loss and improved health. According to the Zone Diet, all meals and snacks consumed throughout the course of the day should strictly adhere to the ratio of 40 percent protein, 30 percent carbohydrate and 30 percent fat. Some aspects of the Zone Diet are in alignment with a healthy eating plan, while others go against dietary recommendations from national associations such as the American Heart Association and The American Dietetic Association.

Healthy Recommendations

The Zone Diet does caution against the intake of saturated fats and refined grains, both of which you should limit in a healthy eating plan. High dietary intake of saturated fat can lead to heart disease, high cholesterol and some cancers. High intake of refined grains, like white breads and pastas, provides little nutritional value in comparison to the amount of calories supplied. The Zone Diet also recommends filling daily carbohydrate needs with fresh fruits and vegetables, which is similar to the USDA's 2010 Dietary Guidelines for Americans recommendations.

Fat Recommendations

To fill the 40 percent protein recommendation on the Zone Diet, the optimal protein foods from which you can choose include lean beef, skinless chicken or turkey, fish, seafood and soy items. All of these protein sources are low in saturated fat. To fill the 30 percent fat requirement, Zone suggests monounsaturated fat sources as the most favorable option. Foods such as nuts, avocados and healthy oils, like olive oil, are good sources of monounsaturated fats that may help lower total cholesterol, increase healthy HDL cholesterol and lower your risk of developing heart disease.

Low Carbohydrate Diets

A problem with the Zone Diet is that it is essentially a low-carbohydrate, high-protein diet. According to the American Dietetic Association, although a low-carbohydrate diet can lead to weight loss in the first six months of the diet, there is no evidence that weight loss, or the maintenance of weight loss, can be maintained for the long-term. Also, the ADA specifically cautions against the safety of low-carbohydrate diet use in people with specific conditions such as osteoporosis or kidney disease.

High Protein Diets

The standard recommendation for daily protein intake, according to the National Academy of Sciences Food and Nutrition Board, is that protein should comprise 10 to 35 percent of your daily caloric intake. In comparison, the Zone Diet's recommendation of 40 percent protein constitutes a high-protein diet. The American Heart Association does not endorse the use of high-protein diets, as they de-emphasize the importance of eating a variety of foods, a practice that helps meet all daily nutrient needs and protect against malnutrition. High protein diets, like the Zone Diet, also tend to restrict the intake of healthy whole grain sources, which can lead to inadequate intake of the nutrients found in these foods.

Considerations

A healthy, balanced diet is built around fresh fruits and vegetables, whole grains, low-fat dairy and lean meats, poultry and fish. It's important to eat a variety of foods to meet all daily nutritional requirements, as well as limit saturated fat and monitor sodium intake. According to a review article in the February 2003 issue of the "Journal of the American College of Nutrition," there is a body of research that supports this nutritional recommendation as the pathway to optimal health. Conversely, no scientific evidence supports achieving good health through alternative nutritional practices like the Zone Diet.