An Interview with Eric C. Westman, M.D., MHS Part 2: Myths and Facts about “Keto”

People are different and so are their responses to diets. If unwanted body fat and/or a state of low-energy are not a problem for you, then congratulations, you have learned what works well for you. Sadly, the majority of people do not share such success in dealing with obesity and metabolic chronic health issues. They are not optimally matching their nutrient input to their genes. The genes of Eskimos are well suited to the traditional Eskimo diet and vice versa. Likewise, indigenous Africans do well on traditional African diets. However, no population has genes well suited for the sugar-laden, overly processed modern diet that is so new to mankind.

If you or your friends have not been satisfied with the responses to trying the same old strategies over and over again, only to be losing headway, then a new strategy is needed. Fortunately, there are a few good choices for healthy diets. For some, it may be a vegetarian diet, for others, it may be a low-carb, high-fat diet. If your genes are showing you that what you are eating now is not giving you the health results you want, then you may wish to look at the health advantages of a low-carb, high-fat diet.

Many people shriek in horror at just the thought of a high-fat diet because they have been told many thousands of times over the past decades that high-fat diets are harmful and the way to lose weight is simply to just not eat fat. Well, how has that worked out for the American public over the last 50 years as the obesity epidemic grew into a pandemic?

As Dr. Eric Westman, M.D., puts it in Keto Clarity (Victory Belt Publishing, 2014), which he co-authored with Jimmy Moore, “(T)he question to ask is ‘what are the health consequences of eating a certain way? What is my health now, and what will my health likely be in the future?’” (1).

Your diet should be based on facts and your body’s responses. Let’s look at facts instead of dogma by continuing our chat with Dr. Westman. Let’s examine the powerful therapeutic health benefits and safety of low-carb, high-fat diets on real people in the real world. We’ll clarify some of the facts about low-carb diets and also discuss the outstanding clinical results obtained by Dr. Westman and his associates at the Duke Lifestyle Medicine Clinic regarding type-2 diabetes, metabolic syndrome, fat loss and more.

Dr. Westman is an associate professor of medicine at Duke University Health System in Durham, NC, and director of the Duke Lifestyle Medicine Clinic. At Duke, he specializes in disease prevention, as well as the treatment of obesity, diabetes and tobacco dependence.

Dr. Westman received his M.D. from the University of Wisconsin/Madison, completed an internal medicine residency and chief residency at the University of Kentucky/Lexington, and completed a general internal medicine fellowship, which included a master’s degree in clinical research.

At Duke since 1990, he has carried out clinical research and clinical care regarding lifestyle treatments for obesity, diabetes and tobacco dependence, and published over 90 peer-reviewed articles.

He is currently the chairman of the board (past-president) of the Obesity Medicine Association (the largest group of obesity medicine specialists in the world) and a fellow of the Obesity Society. He is an internationally known expert on low-carbohydrate nutrition and ketogenic diets.

He is co-editor of the medical textbook,Obesity: Evaluation and Treatment Essentials, author ofA Low Carbohydrate, Ketogenic Diet Manualand co-author ofThe New York Timesbest-sellersThe New Atkins for a New You,Cholesterol ClarityandKeto Clarity.

Passwater:How much weight did your clinic patients lose after a year? What percentage retained their weight loss after a year?

Westman: When carbohydrate restriction (low-carb, high-fat dieting) is used for weight loss, the speed of weight loss is quite variable, but typically is about one to two pounds per week—leading to 50–100 pounds per year of weight loss. The speed of weight loss is faster when individuals stick to the program all the time. Like most medical outpatient treatment programs, about 50% of the people who come through the program will still be in the program after a year.

Our graduates of a four-week program lose an average of 5% of their initial body weight while they are here, and a landmark 80% maintain or continue to lose weight one year later. A striking 85% also report significant health and quality-of-life improvements, such as:
  • Reduced risk of heart disease, diabetes and obesity-related conditions,
  • Reduced disability from arthritis and chronic pain,
  • Improved endurance, mobility, strength and flexibility,
  • A healthier, more balanced approach to eating and activity,
  • Improved ability to manage stress and enhanced mood,
  • A total change of mindset about diet and exercise that works with their lifestyle and enables them to maintain progress at home.
Passwater:Dr. Westman, last month we discussed The New Atkins For A New You (Touchstone, 2010)and also the research done at your Duke Lifestyle Medicine Clinic, but we primarily focused on the diet’s effectiveness and safety (2, 3). Now, let’s clarify what a low-carb, high-fat diet is all about. Are all low-carb, high-fat diets ketogenic diets? Is simply eating a low-carb diet enough?

Westman:Low-carb diets can be categorized by the upper limit of grams of carbohydrates recommended per day. A very-low-carbohydrate diet, or ketogenic diet, typically has fewer than 50 grams of carbohydrates per day, but some individuals need to be even lower than 50 grams. A low-carbohydrate diet is defined as having 50–150 grams of carbohydrates per day. One popular diet today, the Paleo diet, is a type of low-carbohydrate diet and usually has 50–100 grams of carbohydrates per day.

Passwater:Last month, we presented studies that showed ketogenic diets are safe. Let’s go beyond that. Are ketogenic diets natural for humans?

Westman:Yes. Many experts believe that the pre-civilization human diet was ketogenic, at least some times of the year. Being ketogenic just means that the body mainly uses fat and ketones for fuel—not just carbohydrates. The ability to use fat for fuel was extremely important for human evolution.

Passwater:Does a ketogenic diet produce the proper signals to communicate with our DNA for optimal health?

Westman: Many experts believe a low level of ketosis is actually the natural and most optimal state of metabolism for humans. They believe that mankind evolved in a manner that our DNA expresses itself most ideally based upon food sources available for our consumption. Thus, from an epigenetic perspective, many experts believe that the very best way we can communicate with our DNA is to provide it with the signals that, over millennia, it has come to expect.

Passwater:What are ketones and are they toxic?

Westman:Ketones are molecules that carry energy around the body, like glucose. They are healthy under most circumstances, but can also build-up to toxic levels.

Passwater:What is ketosis?

Westman:Ketosis is a metabolic state in which the body is mainly burning fat for fuel. It is called ketosis because the blood levels of ketones are higher than when the body mainly burns carbohydrates for fuel. It happens when you are fasting or when you are consuming a low-carbohydrate, high-fat diet. It is colloquially called, “being in ketosis.”

Passwater:What are some of the health benefits that come from being in ketosis?

Westman:There are many health and well-being benefits from being in ketosis other than losing weight. Most people feel more energetic and have a reduction or elimination of hunger. The therapeutic effects include improvements in obesity, diabetes, prediabetes, high blood triglycerides, low-HDL cholesterol levels, heartburn, fatty liver, irritable bowel disease, polycystic ovarian syndrome and epilepsy.

Some neurologists have noted that ketones stimulate the growth of new neural networks in the brain and increase glutathione levels in the hippocampus, which facilitates the production of mitochondria (2). It can be said that ketosis not only burns off stored fat, but it also powers up the brain. High blood sugar levels damage DNA. Ketosis keeps blood sugar down and thus protects our DNA.

Passwater:Why is it then that so many medical doctors used to think keto-diets were not normal and possibly not good for the body?

Westman:Most medically trained practitioners have only heard about ketosis in the context of ketoacidosis, which is a serious condition that can occur in people with type-1 diabetes. Most practitioners have not been educated about nutritional ketosis, which is the normal state of fat burning.

Passwater:Many diet programs other than low-carb diets cause their followers to be constantly hungry and irritable—a condition often described as being “hangry.” Why do ketogenic diets not cause hunger and irritability?

Westman:Most people in ketosis have much less appetite and feelings of hunger than when they are eating carbohydrates. No one knows the exact mechanism. It is suspected that it is the ketones themselves, but that is one advantage of using a ketogenic diet for weight loss: the lack of hunger. Most other reduced-calorie, high-carbohydrate diet programs make people hungry, which makes them hard to stick to.

Passwater:In Keto Clarity, you mention that low-carb, high-fat keto diets result in most people having more energy (1). Many people are under the impression that energy comes from eating carbohydrates. Yet, there are no dietary essential carbohydrates. There are dietary essential fats, however. There is no such thing as a carbohydrate deficiency, but a deficiency of certain fats can lead to serious health problems. Why do those on keto diets have more energy than those on a high-carbohydrate, low-fat diet?

Westman:When you are in ketosis, your energy (or fuel) comes from fat—not carbohydrates. In fact, if
Vitamin Connection

Eric C. Westman, M.D., M.H.S.

you eat lots of carbohydrates, you will turn off the fat burning! Don’t get me wrong. One can get energy from carbohydrates, but it is not the only way to get energy. If you’ve ever felt sleepy after a meal containing carbohydrates, you’ll see the relationship between carbohydrates and fatigue. I think feeling energized while on the keto diet is caused by not eating energy-reducing carbohydrates.

Passwater:At one time, keto diets were said to only cause a loss of water weight. How did this myth start?

Westman: Keto diets are associated with water weight loss during the first few weeks (if excess water is present to begin with), but then fat loss occurs as well. The myth was started by a two-week study that concluded all of the weight loss was “water weight.” Had the study continued beyond two weeks, then the fat loss would have been seen, too.

Passwater:It seems as if ketone bodies are a superior fuel over blood sugar (glucose.) Is this so? Which organs can use ketone bodies for fuel? Do any systems prefer ketone bodies?

Westman:I think ketones are at least as good as glucose as fuel, and there are some theoretical reasons why ketones may even be the superior fuel. Ketones generate less oxidative stress than glucose, and in laboratory experiments many tissues will use ketones before glucose if the tissue is provided with both options at the same time.

Passwater:I’m fairly familiar with the Inuit (Eskimo) diet and have co-authored a book with Professor Jørn Dyerberg describing the dietary need for the fatty acids EPA and DHA. I joke about the Inuit Food Pyramid being mostly composed of blubber of one kind or another. One surprising thing uncovered by Professor Dyerberg and his colleagues was that not only did the fat-eating Inuit have little heart disease, they also had little diabetes and other chronic age-related diseases. Is the traditional Inuit diet a ketogenic diet?

Westman: Yes, the traditional Inuit diet is a ketogenic diet by the description of the foods. There are several examples of indigenous populations consuming ketogenic diets like the Inuit and several peoples of Africa, including the Masai.

Passwater:What is the mechanism by which ketosis changes the body from being primarily a sugar-burner to a fat-burner?

Westman:One of the mechanisms by which the body is changed into a fat-burning machine is the reduction in insulin levels. Very low insulin levels facilitate the mobilization of fat (triglyceride) from the fat store (adipose tissue). High fat utilization then creates the ketosis, as ketones are made in the liver.

Passwater: What result can be expected from a keto diet in a typical type-2 diabetic?

Westman:The ketogenic diet is an excellent therapeutic diet for someone with type-2 diabetes because the dietary contribution to elevating the blood glucose is basically eliminated. Because there are only five grams of glucose in the bloodstream at any given moment, small amounts of dietary carbohydrate can raise blood glucose levels. If someone is eating 200–300 grams of carbohydrate per day and then changes the diet to 20 grams of carbohydrate per day, there is an immediate reduction in blood glucose of 50–100 mg/dL. Medication for type-2 diabetes must be immediately adjusted to avoid a low blood glucose (hypoglycemia). This kind of powerful diet requires medical monitoring if someone is taking medication for diabetes or high blood pressure.

Passwater: One of the biggest myths about the keto diet is that because it is high fat and cholesterol, it would cause heart disease. As we mentioned last month, the opposite is true. I remember Dr. Atkins being so heavily criticized about his diet and heart disease, yet he was reporting great improvements in his patients’ heart conditions and risk factors. I thought that you and our readers might appreciate this 1975 photo of Dr. Robert Atkins holding my book Supernutrition: Megavitamin Revolution during one of my guest appearances on his radio show (3).


Dr. Westman, please remind our readers about what your experience has been with the heart health of your patients at the Duke Lifestyle Medicine Clinic.

Westman:I’ve observed in our clinic patients the same results that have been found in the research studies: the ketogenic diet reduces cardiometabolic risk factors by lowering inflammation, blood triglyceride levels, body weight, abdominal circumference and raising the good HDL cholesterol. I have not seen an increase in heart disease or stroke, but in all honesty it would be difficult for a clinic to detect small increases in these problems without a formal research study. I am hopeful that this kind of “outcome research” will be done soon.

Passwater: InKeto Clarity, you also discuss several other conditions that have been helped by keto diets (1). We can’t discuss all of them here as it would take a book, but can you list several that should be called to the attention of our readers?

Westman: Keto diets are most known for their use for weight loss, but also are excellent for diabetes, high blood pressure, heartburn, fatty liver, irritable bowel disease, polycystic ovarian disease and epilepsy.

Passwater:Your books can be purchased at any bookseller, but how can people who want more guidance contact your clinic?

Westman:My clinic is located at Duke University in Durham, NC, and I’ve seen people there since 2007. I’m also assisting with two new companies to “get the word out”: Adapt Your Life ( and HEAL Diabetes & Medical Weight Loss Clinics ( Adapt Your Life provides information for general use, and HEAL Clinics provides medical supervision if people have medical conditions or are taking medications.

Passwater:Dr. Westman, thank you once again for informing our readers about the health benefits and safety of low-carbohydrate, high-fat diets. Perhaps, we can continue our discussion next month. WF


1. J. Moore, and E.C. Westman,Keto Clarity(Victory Belt Publ., Inc. Las Vegas, NV, 2014). 2. R.A. Passwater, “The Health Benefits and Safety of Low-Carb, High-Fat Diets. An Interview with Eric C. Westman, M.D. Part 1: The Proven Experience,” WholeFoods Magazine 39 (1), 38–40 (2016), E.C. Westman, S.D.  Phinney and J.S. Volek, The New Atkins for a New You: The Ultimate Diet for Shedding Weight and Feeling Great (Fireside Div., Simon & Schuster, Inc., New York, 2010) 4. D. Perlmutter,, accessed Dec. 17, 2015. 5. R.A. Passwater,Supernutrition: Megavitamin Revolution (Dial Press, NY, 1975).Vitamin Connection

Dr. Richard Passwater is the author of more than 45 books and 500 articles on nutrition. Dr. Passwater has been WholeFoods Magazine’sscience editor and author of this column since 1984. More information is available on his website,




Published in WholeFoods Magazine, February 2016