Mark Hyman

Related Terms

Functional foods, Mark Hyman, nutrigenomics, Ultrametabolism, weight loss.


Ultrametabolism is a diet book written by Dr. Mark Hyman that aims to help individuals obtain an optimal state of health by consuming foods that will improve wellness and prevent disease. The author claims that eating a healthier diet will improve the individual's likelihood of staying well and losing weight by changing the body's expression of genes.
The key concept of Ultrametabolism is nutrigenomics, a concept created by Hyman. Though the specifics of his theory are vague, the author claims that certain foods will cause the genes present in better health to be expressed more often, while the genes predisposing an individual to health problems (such as obesity, which is in part a trait inherited from one's parents) will be expressed less often.
Hyman bases his theory for weight loss on the theory that foods humans have eaten over the past 2,000 years before the rise of fast food culture in industrialized nations were healthier. Though the diets of people throughout the world have always been incredibly varied and their availability and quality is usually based on a complex equation of resource availability and distribution, Hyman does not delve into specifics. Regardless, Hyman claims that such information has been passed down as "folk knowledge."
Hyman explicitly advocates his diet as a means of primarily achieving weight loss, although an optimal state of health supposedly achieved by consuming the food regimen outlined in Ultrametabolism is necessary to reach this goal.
The author developed his diet plan by working with over 2,000 patients in private practice to help them achieve weight loss. Although the Ultrametabolism website claims that there is scientific research to support this diet plan, no citations or consensus statements are cited. Although the diet has been featured in many popular magazines and talk shows, no available higher quality human trials have been conducted on the Ultrametabolism diet.
The popularity of Ultrametabolism rides on the trend of diets that encourage people to eat a balanced diet recommended by the U.S. Department of Agriculture (USDA), rather than discarding commonly accepted principles of nutrition to lose weight.

Theory / Evidence

The author of Ultrametabolism claims that eating the foods he advocates and practicing a low stress lifestyle will "program" the body to regain health and lose weight. Hyman claims that food and behavior tell genes how to behave.
Although environmental and behavioral factors are known to have some influence on gene expression, no higher quality trials have shown these aspects of day to day living to exert complete and simultaneous control on all aspects of gene expression.
Ultrametabolism claims that the reader should be more aware of the purported lifestyle and diet modifications that may result in complete control over health and body size. Because he believes that government and medical organizations do not do enough to educate the consumer on the benefits of some sorts of food and exercise, Hyman urges individuals to adopt a healthy lifestyle.
Assessment of weight involves evaluating body mass index, waist circumference, and the patient's risk factors.
BMI=weight (kg)/[height (m)]2
Overweight is defined as a BMI of 25-29.9 kg/m2
Obesity is defined as a BMI of ?30 kg/m2
Waist circumference for men >40 inches or women >35 inches indicates an increased risk for those with a BMI of 25-34.9.
Coronary heart disease or other atherosclerotic diseases, type 2 diabetes, and sleep apnea are factors associated with a very high risk of developing disease complications and mortality.
Weight loss is recommended for those who are obese (BMI ?30kg/m2) and for those who are classified as overweight (BMI of 25-29.9kg/m2) or have a high waist circumference and two or more risk factors.
A 2007 article in the Mayo Clinic Proceedings stated that treatment of obesity requires the physician and patient to address diet, physical activity, and behavioral issues. In some cases, medication and surgical treatments not discussed in Ultrametabolism may offer other options.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (


Functional Medicine: Find a Physician.
Thompson WG, Cook DA, Clark MM, et al. Treatment of obesity. Mayo Clin Proc. 2007 Jan;82(1):93-101; quiz 101-2. Review.
United States Department of Agriculture (USDA).


Hyman advocates for patients to consume a greater number of functional foods. Functional foods, also called nutraceuticals (a combination of the words "nutrition" and "pharmaceuticals"), are considered to be any food that possess beneficial health and wellness properties beyond the well proven nutritional benefits a person might find on the food label. The supposed benefits of functional foods go beyond the dietary needs listed on the USDA's food pyramid. Functional foods are reported as one of the fastest growing segments of the food economy in United States.
Readers are instructed to entirely avoid so-called "junk food," including fried foods, highly sugared foods, and non-organic foods. These diet suggestions are more stringent than those advocated by the USDA, which created the food pyramid as a diet guideline for Americans. Refined sugars and carbohydrates from white flour are to be eliminated. When possible, Hyman suggests the reader buy organic foods or cook meals from fresh ingredients. Whole, unrefined, unprocessed plant foods are broadly advocated over food in packages or foods with many artificial ingredients. Additives, according to the Ultrametabolism diet, will only exacerbate difficulty with weight loss.
Hyman suggests strict adherence to an eating schedule. Ultrametabolism instructs individuals to eat three solid meals a day, with very little snacking in between. Further, the book states that readers should not try to starve themselves in order to loose weight. To this end, counting calories as a means of achieving weight loss is not encouraged.
Ultrametabolism tells its readers that stress puts the body into a "fight or flight" mode. To this end, the body stores more fats and taxes the endocrine system in order to prepare for survival. Hyman proposes that eating a lower-fat diet will help the endocrine system regulate itself more effectively.
Hyman advocates for an increased integration of antioxidants into the diet. The author links free radicals to a variety of health concerns, including difficulty in losing weight. Antioxidants are found in a variety of fruits and vegetables.
Ultrametabolism claims that up to 20% of Americans have undiagnosed thyroid disorders. Because thyroid disorders affect metabolism and hormones in the body, Dr. Hyman claims that they interfere with weight loss. To this end, a part of this diet involves visiting a doctor for screening of a thyroid problem.
Liver detoxification is suggested, although the details on this process are not articulated. In general, individuals may detoxify their livers through a variety of practices, such as taking milk thistle or engaging in an at-home procedure known as "liver flushing."
Although there are no doctors licensed to practice the Ultrametabolism diet, the website provides a link to an integrative medical doctor search function.