Ketogenic diets, which are high in fat, very low in carbohydrate and moderate in protein content, have surged in popularity. Traditionally used to manage medical conditions such as epilepsy, ketogenic diets are commonly used to facilitate weight loss and treat obesity.

On a normal diet, blood ketone levels are very low and the brain uses glucose as a fuel. During prolonged fasting or diets very low in carbohydrate, ketones are formed in the liver to provide an alternate fuel for the brain, greatly prolonging the amount of time humans can survive in states of starvation. Weight reduction is difficult to maintain because the sustained reduction in energy intake triggers a strong physiological drive to increase energy intake to maintain weight. Weight maintenance on a ketogenic diet may be facilitated because the high blood ketones reduce hunger.

Some nutritionists may not recommend ketogenic diets for long-term use, as their long-term safety is unclear. However, recent research suggests that ketogenic diets may have health benefits, including therapeutic potential for diabetes and cancer, among other conditions.

There are several types of clinical trials that can be used to support ketogenic food products:

Equivalent Glycemic Load (EGL)

EGL trials measure postprandial glycemic response to foods that are very low in carbohydrate content. EGL trials demonstrate whether foods marketed for a ketogenic diet have a low glycemic impact.

Maintenance of Nutritional Ketosis

Achieving nutritional ketosis takes several days and careful attention to foods consumed. A clinical trial determines if a food product will maintain nutritional ketosis to substantiate product claims.

Weight Loss

Ketogenic diets are commonly used to promote weight loss and treat obesity. Long term weight loss trials demonstrate the effect of a ketogenic diet using specific food products to promote and maintain weight loss.

Satiety Trials

Products that promote feelings of satiety help people adhere to weight loss plans. Acute trials assess the satiating effects of specific food products to support their use in weight loss programs.