Doctors and other health professionals discuss what we know and what don’t know.

To write that “we know surprisingly little about the science of nutrition” is wrong. Most people do not need personalized diets.

A whole foods, plant-based diet naturally low in fat and sugar has been scientifically proved to prevent and even reverse a wide variety of chronic diseases, including heart disease, Type 2 diabetes, hypertension and early-stage prostate cancer, especially when combined with moderate exercise, social support and stress management.

Why? Because these illnesses share the same underlying biological mechanisms.

Even if there are individual differences — how efficiently a person metabolizes dietary refined carbohydrates or fat — these don’t matter if a person isn’t eating too much of these. It’s why countries like China had such low rates of chronic diseases despite individual genetic variations until they started to eat like us, live like us and die like us.

To say that artificial intelligence is needed to design a diet based on your microbiome is incorrect since a healthy diet can quickly change your microbiome in beneficial ways.

Recommending foods like red meat and bratwurst, which the World Health Organization defined as potent carcinogens, shows how flawed A.I. can be.

Dean Ornish
Kim Allan Williams Sr.
Dr. Ornish is a clinical professor of medicine at the University of California San Francisco and co-author of “UnDo It!: How Simple Lifestyle Changes Can Reverse Most Chronic Diseases.” Dr. Williams is a former president of the American College of Cardiology.

As a registered dietitian and a health educator who has been working in the field for more than 30 years, I have come to the conclusion that we know both so much and so little about nutrition as it relates to health. The bottom line is that diet’s effect on health is multifaceted, and blood glucose level is only a fraction of the important information for health outcome predictors.

Individual variability is based on genes, environment, stress levels and so on. While I strongly believe that the future of dietary recommendations should be based on an individual’s needs, we are a long way from being able to do this in an accurate and comprehensive fashion.

Elizabeth Schwebel Wind
White Plains

Diet is one of a collection of lifestyle factors, including physical inactivity, poor sleep, tobacco use, stress and non-adherence to medical regimens that account for 80 percent of chronic disease. These behaviors are driven by complex interactions between biological, environmental and social determinants of health.

The broad focus on behavior, its determinants and disease describes the scope of the field of behavioral medicine. We have subsisted for 40 years on less than 3 percent of the National Institutes of Health budget. No substantive progress will be made in tackling preventable disease until we can understand and control the forces driving the public toward unhealthy lifestyles, including but not limited to diet.

Sherry Pagoto
Storrs, Conn.
The writer is president of the Society of Behavioral Medicine and a professor of allied health sciences at the University of Connecticut.

To the Editor:

Re “We Need Better Answers on Nutrition”:

We need real food, preferably, food not grown with cancer-causing agents. It should be affordable. Instead, taxpayers subsidize the corn growers and other commodity crops. Corn gets turned into high-fructose corn syrup, which sweetens foodlike substances, which are cheaper because of those subsidies.

The fake-food companies make fortunes off that addicting, cheap and convenient fake food because busy people working several minimum-wage jobs can’t afford real food and don’t have time to cook it anyway.

We know what makes people healthy, but the political will to change public policy to get us to a healthy society isn’t there. It’s ironic that this article was written by a hedge fund manager, a former commissioner of the Food and Drug Administration and a former agriculture secretary.

The alliance between Wall Street and our government has produced a food and economic culture that is a recipe for ill health.

Judith Dasovich
Springfield, Mo.
The writer is an internist.

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