The Health Benefits and Safety of a Low-Carb, High-Fat Diet

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An Interview with Eric C. Westman, M.D., Part One

Here’s wishing you a healthy, happy and satisfying New Year. The New Year is usually a time when many of our friends once again resolve to improve their lifestyle and nutrition. Some of them try once again to shed some unwanted pounds. They may even come to you for advice on healthy dieting. So, this month, I am asking Eric Westman, M.D., past-president of the Obesity Medicine Association and director of the Duke Lifestyle Medicine Clinic in Durham, NC, to discuss what his experience has been.

I have always been amazed at how emotional supporters of various dietary regimes can become and how limited their evidence is. With the official dietary recommendations finally recognizing the errors—actually they were deliberate falsifications—of past decades of guidance, it is time to look at what truly works in real life with real people. For instance, it is now well established that dietary cholesterol and saturated fats are not the villains once erroneously suggested by fudged “studies.”

This column has previously discussed how incorrect and fudged data were used in denigrating saturated fats (1–5).

Now, the proposed official 2015 U.S. Dietary Guidelines may no longer suggest limiting dietary cholesterol nor propose an upper limit for dietary fat (6, 7).

Theory is one thing, but real life is more important. What works for real people in the real world? Results speak for themselves.

Dr. Eric C. 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 co-editor of the medical textbook, Obesity: Evaluation and Treatment Essentials, as well as the author of The New York Times best sellers, The New Atkins for a New You, Cholesterol Clarity and Keto Clarity.

Passwater: Dr. Westman, why did you become a physician?

Westman: It may sound corny, but I became a physician to “help people.” My father was a physician and it was always what I wanted to be.

Passwater: Why did you specialize in internal medicine and obesity medicine?

Westman: While in medical school, I enjoyed figuring out problems, being a detective much like Dr. House on television, which generally leads medical students to internal medicine as a specialty. While in a clinical research fellowship, several of my patients lost weight and improved their medical conditions, which intrigued me to study obesity medicine.

Passwater: Dr. Westman, your clinic is extremely highly regarded internationally for successfully helping people improve their health. You address many lifestyle problems that affect obesity, diabetes and heart disease. Please tell our readers about your history, mission and its success.

Westman: After doing 10 years of clinical research into the safety and efficacy of low-carbohydrate lifestyles, like the Atkins Diet, I established the Duke Lifestyle Medicine Clinic to implement what we had learned through research in a practical clinic setting. I routinely use the low-carbohydrate lifestyle approach to improve diabetes, obesity and metabolic syndrome, which is now regarded as a main contributor to heart disease. Within a university setting, I also use the clinic to teach visiting doctors and dietitians how to implement a low-carbohydrate lifestyle.

Passwater: Which came first: treating obesity, diabetes or heart disease? Was there a natural progression?

Westman: During our first study of the low-carbohydrate lifestyle for obesity, I became aware of the history of using low-carbohydrate diets to treat diabetes in the early 1900s. Then in the early 2000s, the clinical research of Jeff Volek, Ph.D., from Ohio State University made it clear that low-carbohydrate diets could address metabolic syndrome. The progression for me was: obesity, diabetes and heart disease.

Passwater: Is there a particular treatment or diet that you use to achieve this success, or are patients given personalized or individualized regimens?

Westman: Though the approach I use is based upon restricting carbohydrates, patients come up with their own regimens because they choose the food and beverages they like from a list of very low-
carbohydrate foods and beverages.

Passwater: How did you arrive at this protocol? Was there a body of evidence that impressed you, or was it trial and response with patients’ experiences?

Westman: The protocol we use is based upon clinical research studies that we conducted starting in 1998 (8, 9). Our research protocol was influenced by several prominent low-carb clinicians, including Dr. Atkins.

Passwater: The results from your clinic are impressive and stand out. However, your protocols do not seem to be widely embraced. Is this because other physicians have been taught that diets should be low fat or is it because they haven’t looked at the evidence and results? Or, are diet programs such as yours considered “mainstream” now?

Westman: I think researchers generally accept the low-carbohydrate lifestyle as a therapeutic treatment for diabetes, obesity and metabolic syndrome. It takes time for the research to spread into clinical practice. Not everyone agrees that the low-carbohydrate lifestyle is a generally healthy lifestyle—but it is as shown by my clinical experience and the clinical experience of other doctors.

 

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Passwater: Your experience led you and your colleagues to develop what you call “The New Atkins Diet” (10).

Westman: Yes, “The New Atkins Diet” involves the use of “net carbs,” a calculation that subtracts fiber grams from the total carbohydrate grams. “The New Atkins Diet” is a great resource for the low-carb diet and as a general nutritional information guide. We wrote the last two chapters as a research update for doctors and dietitians.

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Passwater: What is the advantage of using net carbs versus total carbs?

Westman: By counting only net carbs, you are only considering the grams of carbohydrate that affect your blood sugar level, not total carb grams, since fiber doesn’t sabotage your body’s use of fat.
“The New Atkins Diet” is a departure from the original Atkins Diet because it uses net carbs instead of total carbs to begin the initial phase of the program. The New Atkins Diet works very well for most people. I still use the original Atkins Diet approach of using total carbs if an individual is extremely obese or has a serious metabolic problem like diabetes or metabolic syndrome.

Passwater: Back in the 1970s, when I was a frequent guest on the Dr. Atkins radio show, his critics were emotional in their unsupported claims that his diet would cause heart disease and was dangerous. He would invite me as a radio guest because of the evidence I presented in my writings about dietary cholesterol not being a significant factor in blood cholesterol levels nor in heart disease risk (11). Dr. Atkins knew that his patients actually reduced their blood cholesterol and blood sugar (glucose) levels on his diet. Now low-carb, high-fat diets have been well-studied and proven very safe and very effective. Could you please point out a few of these studies so that any skeptical readers can check the science?

Westman: There are several studies in major medical journals easily found in most libraries and on the Internet that your readers may find of interest.

Generally, studies comparing low-carbohydrate diets with reduced-calorie diets have shown that weight loss can be greater with a low-carbohydrate diet for durations of six months or less. Similar or better results have been found for durations up to two years (12–14).

A review article published in the American Journal of Clinical Nutrition in 2007 concluded, “Carbohydrate-restricted diets lead to appetite reduction, weight loss and improvement in surrogate markers of cardiovascular disease” (15).

The summary reported, “low-carbohydrate diets improve glycemic control (blood sugar control) and insulin resistance (reduced ability of cells to use insulin) in healthy persons and in persons with type-2 diabetes. In controlled trials for weight loss, the low-carbohydrate diet leads to weight loss, and improvements in fasting triglycerol, HDL cholesterol, and the ratio of total to HDL cholesterol over a 6–12 month period. ”

The report concludes, “Some form of low-carbohydrate diet may be the preferred choice for weight reduction as well as general health.”

The following year, a two-year study was published in the New England Journal of Medicine that randomly assigned 322 moderately obese persons to one of three diets: a low-fat, restricted-calorie diet, a restricted-calorie Mediterranean diet, or a low-carbohydrate, non–restricted-calorie diet (14). The researchers concluded, “Mediterranean and low-carbohydrate diets may be effective alternatives to low-fat diets. The more favorable effects on lipids (fats and cardiovascular risk factors) with the low-carbohydrate diet and on glycemic control with the Mediterranean diet suggest that personal preferences and metabolic considerations might inform individualized tailoring of dietary interventions.”

In 2009, the long-term weight loss and cardiometabolic effects of a very low-carbohydrate, high-saturated-fat diet was compared under isocaloric conditions with a high-carbohydrate, low-fat diet (16).

The low-carbohydrate diet group had greater decreases in triglycerides and increases in HDL cholesterol. This Australian study concluded, “Under planned isoenergetic conditions, as expected, both dietary patterns resulted in similar weight loss and changes in body composition. The low-carb diet may offer clinical benefits to obese persons with insulin resistance.”

 

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In 2010, a study was published in the Archives of Internal Medicine that compared a low-carb diet with a low-fat diet; the latter was also given with a weight-loss drug (17). In this study, 146 men were randomly given either the low-carb diet or the drug plus low-fat diet. Weight loss was similar in both groups. However, those consuming the low-carb diet had better improvement in systolic and diastolic blood pressures than the drug plus low-fat diet group. Both groups had similar improvements in HDL cholesterol and triglyceride levels. Also, glucose, insulin and hemoglobin A1c levels improved within the low-carb diet group only.

The researchers concluded, “In a sample of medical outpatients, a low-carb diet led to similar improvements as a drug plus a low-fat diet for weight, serum lipid, and glycemic parameters and was more effective for lowering blood pressure.”

Passwater: Well, they certainly establish a solid body of science to show the effectiveness and safety of the low-carb diet, as well as prove that the low-carb diet is best for the heart and for controlling metabolic syndrome or type-2 diabetes. This is what Dr. Atkins saw in his patients, but his uninformed critics kept insisting that the low-carb diet would be just the opposite. Dr. Atkins was a physician in private practice and did not have a university clinic to run the randomized clinical trials (RCTs) that everyone seems to need these days. This is where physicians such as you have made great contributions to the health of people everywhere thanks to your RCTs. Besides RCTs, the trend is to look at meta-analyses. Meta-analyses are statistical methods of combining evidence from similar clinical trials. Are any recent meta-analyses of interest?

Westman: In 2012, a meta-analysis published in the American Journal of Epidemiology compared the effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors (18). Twenty-three trials from multiple countries with a total of 2,788 participants were included in the analysis.

Both low-carbohydrate and low-fat diets lowered weight. Compared with participants on low-fat diets, individuals on low-carbohydrate diets had a greater improvement in HDL cholesterol and a greater decrease in triglycerides and improved metabolic risk factors. The meta-analysis concluded, “Low-carbohydrate diets could be recommended to obese persons with abnormal metabolic risk factors for the purpose of weight loss.”

Passwater: Now, how’s this for good timing? Just as we are going to press, an online publication of a new meta-analysis has just appeared (19). The study will be published in The Lancet: Diabetes & Endocrinology. It is a meta-analysis of RCTs comparing the long-term effect of low-fat and higher-fat dietary interventions (such as low-carb diets) on weight loss. The analysis examined 53 studies involving 68,128 participants.

The meta-analysis found that in weight-loss trials, higher-fat (low-carbohydrate) weight-loss interventions led to significantly greater weight loss than low-fat interventions. The average dieter on a low-carb diet lost an average of 33% more weight than the average dieter on a low-fat diet after a one-year follow up.

The Harvard Medical School researchers concluded, “Evidence from RCTs does not support low-fat diets over other dietary interventions for long-term weight loss.”

Visiting your clinic might be a good solution for many with lifestyle health problems. For those who can’t wait, what results could they expect from reading your “New Atkins” book?

Westman: We wrote, The New Atkins for a New You to be a primer for basic nutrition, as well as to be a “how-to” guide to a low-carbohydrate lifestyle. Should someone decide to change to a low-carbohydrate lifestyle, the book is packed with practical suggestions to make that transition as easy as possible.

Passwater: Well, that is encouraging, but what is the science behind the diet? Let’s discuss how and why low-carb, high-fat diets work to safely shed excess body fat and, perhaps more importantly, help diabetics control their blood sugar in future columns. WFdr. richard passwater

Dr. Richard Passwater is the author of more than 45 books and 500 articles on nutrition. Dr. Passwater has been WholeFoods Magazine’s science editor and author of this column since 1984. More information is available on his Web site, www.drpasswater.com.

 

SEE PART TWO OF THIS INTERVIEW HERE.

 

 

References
1. D. Mozaffarian  and D.S. Ludwig, “The 2015 U.S. Dietary Guidelines: Lifting the Ban on Total Dietary Fat,”
JAMA 313 (24), 2421–2422 (2015).
2. L. Nicholson, “U.S. May Lower Cholesterol’s Level of Threat to Health: Report,” Feb. 10, 2015, www.reuters.com/article/2015/02/10/us-usa-health-cholesterol-idUSKBN0LE2GQ20150210, accessed Nov. 13, 2015.
3. R.A. Passwater, “From Pellagra to Trans Fats and Beyond — How a Legendary Nutritional Scientist Is Still Saving Countless Thousands From Premature Deaths,” WholeFoods Magazine, 37 (10), 48–50, 52 (2014).
4. R.A. Passwater, “Why and How To Reduce Trans Fats: Surprising Facts About All Fats,” WholeFoods Magazine, 37 (9), 74–79 (2014).
5. R.A. Passwater, “Saturated Fat Is Not the Major Issue in Heart Disease,” WholeFoods Magazine, 37 (3), 68–69 (2014).
6. R.A. Passwater, “Heart Nutrition and the Great Cholesterol Myth,” WholeFoods Magazine, 36 (3), 43–45, 48 (2013).
7. R.A. Passwater, “The Cholesterol Paradigm: The Greatest Health Scam of the Century,” WholeFoods Magazine, 32 (12), 30–36 (2009).
8. E.C. Westman, “A Review of Very Low Carbohydrate Diets for Weight Loss,” J. Clin. Outcomes Manag. 6, 36–40 (1999).
9. J.S. Volek and E.C. Westman, “Very-Low-Carbohydrate Diets Revisited,” Cleve. Clin. J. Med. 69 (11): 849, 853, 856–858 passim (2002).
10. E.C. Westman, S.D. Phinney and J.S. Volek, The New Atkins For a New You (Touchstone Book, Simon & Schuster, NY, 2010).
11. R.A. Passwater, Supernutrition For Healthy Hearts (Dial Press, NY, 1977).
12. A.J. Nordmann, et al., “Effects of Low-Carbohydrate versus Low-Fat Diets on Weight Loss and Cardiovascular Risk Factors: A Meta-Analysis of Randomized Controlled Trials,” Arch. Intern. Med. 166 (3), 285–293 (2006).
13. M. Hession, et al., “Systematic Review of Randomized Controlled Trials of Low-Carbohydrate versus Low-Fat/Low-Calorie Diets In the Management of Obesity and its Comorbidities,” Obes. Rev. 10 (1), 36–50 (2009).
14. I. Shai et al., “Dietary Intervention Randomized Controlled Trial (DIRECT) Group. Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet,” N. Engl. J. Med. 359 (3), 229–241 (2008).
15. E.C. Westman et al., “Low-Carbohydrate Nutrition and Metabolism,” Am. J. Clin. Nutr. 86, 276–284 (2007).
16. G.D. Brinkworth et al., “Long-Term Effects Of A Very-Low-Carbohydrate Weight Loss Diet Compared With An Isocaloric Low-Fat Diet After 12 Mo.,” Am. J. Clin. Nutr. 90 (1), 23–32 (2009).
17. W.S. Yancy, Jr., et al., “A Randomized Trial of a Low-Carbohydrate Diet versus Orlistat Plus A Low-Fat Diet For Weight Loss,” Arch. Intern. Med. 170 (2), 136–145 (2010).
18. T. Hu, et al., “Effects of Low-Carbohydrate Diets versus Low-Fat Diets on Metabolic Risk Factors: A Meta-Analysis of Randomized Controlled Clinical Trials,” Am. J. Epidemiol. 176 (Suppl 7), S44–S54 (2012).
19. D.K. Tobias, et al., “Effect of Low-Fat Diet Intervention versus Other Diet Interventions on Long-Term Weight Change in Adults: A Systematic Review and Meta-Analysis,” The Lancet: Diabetes & Endocrinology. Pub Online 29 Oct 2015. DOI http://dx.doi.org/10.1016/S2213-8587(15)00367-8

Published in WholeFoods Magazine, January 2016