Zone diet

History:

The Zone diet was created in 1995 by biochemist Barry Sears (1). Sears claims this is an anti-inflammatory diet that aids in rapid weight loss and improves the body's performance. The name of the diet refers to three specific clinical markers being “in the Zone” to control diet-induced inflammation. Being in the zone is defined by the TG/HDL ratio, AA/EPA ratio, and HbA1c. These clinical markers indicate the level of insulin resistance in the liver, level of diet-induced inflammation in the body, and blood glucose levels.1 The Zone diet emphasizes a protein to glycemic load balance to promote hormonal and anti-inflammatory benefits. This diet ranked 20 out of 35 in US News Best Diet Overall for 2020.

Purpose:

The Zone Diet aims to make sure your insulin and other inflammatory hormones stay in balance, “in the zone,” by eating a diet with 40% calories from low glycemic index carbohydrates, 30% calories from fat, and 30% calories from protein. Ultimately, by consuming the right proportions of macronutrients at each meal the body will be able to function at peak performance while maintaining a healthy and slim figure (2).

General dietary practices:

This diet supports eating three meals a day and two snacks that fall within the caloric ratio below (3): 

  • 30% calories from lean protein such as egg whites, fish, poultry, lean beef, and low-fat dairy

  • 40% calories from carbohydrates low in glycemic index and low in glycemic load such as fruits and vegetables. However, fruits containing high sugar content and starchy vegetables like potatoes should be avoided 

  • 30% calories from fat such as olive oil, avocado, and nuts, with specific emphasis on omega-3 fatty acids and monounsaturated fats

Additionally, this diet promotes the use of supplements. It is recommended to take fish oil that contains omega-3 fatty acids and polyphenol supplements

Key concerns:

The Zone diet does not favor dairy products, therefore consuming enough calcium on this diet is a concern and may lead to a deficiency. Due to food restrictions, there may be a lack of vitamin C, folate, B vitamins, and fiber in the diet. This diet is higher in fat and protein than the typical American diet therefore is not advised for people at risk for kidney disease, people with high blood pressure, and people who need to monitor their blood pressure. Additionally, this diet is expensive not only because the cost of food is high, but fish oil and polyphenol supplements can be costly. This diet may be difficult to follow for the long-term due to its strict macronutrient composition needing to be met at every meal, restrictions on many common foods, and calorie restriction. There is not enough scientific evidence to support the claims of this diet.

Further Resources:

Books: Enter The Zone: A Dietary Road map, by Barry Sears.

Websites: 

**The information presented provides an overview of the diet along with credible resources to refer to in order to learn more. This is not intended to make any dietary recommendations, rather an education tool for our clients.**

Reference:

  1. Zone Diet: Leading Anti-Inflammatory Food & Supplements. Dr. Sears' Zone Labs. https://www.zonediet.com/. Published 2020. Accessed July 26, 2020.

  2. US News the Best Diet 2020. https://health.usnews.com/best-diet/zone-diet. Published 2020. Accessed July 26, 2020.

  3. The Zone Diet. Dr. Sears' Zone Labs. https://www.zonediet.com/the-zone-diet/. Published 2020. Accessed July 26, 2020