DAA’s views on Low Carbohydrate Diets
First posted 5.7.2015
I asked Richard Feinman, Professor of Cell Biology at the State University New York Downstate Medical Center and author of The World Turned Upside Down: The Second Low-Carbohydrate Revolution, to comment on statements made by the DAA regarding Low Carbohydrate Diets.
DAA: “Not all “low carbohydrate diets” are the same. These diets vary greatly in quality and in how much carbohydrate, protein and fat they contain. It is important to ensure that the diet information you are getting comes from a credible source.”
Professor Feinman: Credible sources on low-carbohydrate diets are laboratories or clinics that have studied such diets and that have good success and are able to explain how they work and how to implement them in your personal setting. Beware of official organisations that have numerous undocumented warnings and, most of all, little or no interaction with people who have actually done the research.
DAA: “Low carbohydrate and high protein diets have recently been promoted for weight loss. Books have especially focused on people who have the cluster of disorders known as Syndrome X or the Metabolic Syndrome.”
Professor Feinman: Extensive peer-reviewed studies have shown that low-carbohydrate diets are most effective for people with metabolic syndrome.
- Cornier MA, Donahoo WT, Pereira R, Gurevich I, Westergren R, Enerback S, Eckel PJ, Goalstone ML, Hill JO, Eckel RH et al: Insulin sensitivity determines the effectiveness of dietary macronutrient composition on weight loss in obese women. Obes Res 2005, 13(4):703-709.
- Volek JS, Feinman RD: Carbohydrate restriction improves the features of Metabolic Syndrome. Metabolic Syndrome may be defined by the response to carbohydrate restriction. Nutr Metab (Lond) 2005, 2:31.
- Volek JS, Fernandez ML, Feinman RD, Phinney SD: Dietary carbohydrate restriction induces a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome. Prog Lipid Res 2008, 47(5):307-318.
- Volek JS, Phinney SD, Forsythe CE, Quann EE, Wood RJ, Puglisi MJ, Kraemer WJ, Bibus DM, Fernandez ML, Feinman RD: Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids 2009, 44(4):297-309.
DAA: “Low carbohydrate diets are not new and have regularly come in and out of fashion. However, there has been no long-term research into how well these diets work in treating obesity and its associated disorders of high cholesterol, high blood pressure and insulin resistance.”
Professor Feinman: They are not new and have consistently been shown to be effective. As other diets — low-fat, Mediterranean, Low-GI, Vegetarian — come and go and as they fail to live up to their promise, people return to low-carbohydrate diets which continue to work despite the medical establishment coming up with “concerns.” Low-carb diets are best for diabetes and metabolic syndrome, dramatically improve HDL “good cholesterol,” triglycerides and small-dense (atherogenic) LDL. The response of total cholesterol and total LDL is variable but these markers have failed to be any kind of reliable indicator of health risk. Low carbohydrate diets reliable reduce blood pressure and improve insulin resistance. The statement in the DAA guidelines are demonstrably false and indicate ignorance or bias or both.
DAA: “Some low carbohydrate and high protein diets are of concern because they encourage an excessive intake of saturated fat. There is considerable research that links a high saturated fat diet with an increased risk of heart disease and damage to blood vessels.”
Professor Feinman: “Of concern” is not data. The history of saturated fat in the diet is one of refusal of the medical establishment to accept the failure of the considerable research. Whether one considers this a scandal or simple faltering progression of medical history, the record is clear: the Framingham study showed no effect of dietary total or saturated fat or cholesterol on cardiovascular disease. The failure was repeated by the Tuscaloosa study, The Oslo Heart Study, The Western Electric Study, The Minnesota study and, ultimately The Women’s Health Initiative (WHI) which found no effect on heart disease, weight loss or diabetes, of a diet low in total or saturated fat or cholesterol. Characteristically, in response to the WHI, Elizabeth Nabel, head of NHLBI got on the media to say “nothing’s changed.” (The sole study that is claimed to have shown an effect, the Finnish Mental Hospital Study, was so compromised by methodological problems that it wasn’t clear whether it was the researchers or the patients who were confronting the largest cognitive problems). If the “increased risk of heart disease and damage to blood vessels” were as stated in the DAA guidelines not one of these studies should have failed. Not one. But they all failed. The DAA is not alone in voicing “concerns” that have no basis in fact.
Professor Feinman: The evidence for the importance of fiber is very poor if commonly touted by “experts.”
Widely claimed on the basis of anecdotal evidence but never really studied, most people feel that whatever the truth, constipation is easier to deal with than obesity, diabetes and increased cardiovascular risk factors such as HDL, triglycerides and pattern B LDL.
DAA: “A high protein diet is usually not recommended for people with any degree of kidney impairment or renal disease.”
Professor Feinman: Low-carbohydrate diets are not usually high protein except compared to the protein-deficient diets that many adapt in trying to conform to the standard high carb recommendations. The most widely respected researchers in low-carbohydrate biochemistry are explicit that a low-carbohydrate should not be high protein although protein tends to be a stable part of the diet.
People with any disease should follow recommendations of a physician. What the comment is implying is that high protein (again, not a recommended feature of most low-carbohydrate diets) is a risk for people with normal kidneys. This has now been disproved so many times that, unusual for the medical media, the facts actually appear to be taking hold. This is presumably why this devious approach is being taken by health agencies. In people with diabetes or any degree of insulin resistance, it is the hyperglycemia that is the major risk for renal disease. People with diabetes are at risk for CVD because of the diabetes and you improve that by reducing carbohydrate.
DAA: “Recent reviews into low carbohydrate diets indicate that they are effective in reducing body weight for up to six months.”
Professor Feinman: They have been shown to be effective for up to two years and, significantly, always better in comparison to low-fat diets or diets similar to those recommended by DAA for as long as they are compared. If there were any science in organizations like the DAA, they would fund the long term studies whose clear benefits they want to see last longer.
DAA: “There is evidence to suggest that, for some people, low carbohydrate diets are easier to comply with than low fat diets.”
Professor Feinman: All real evidence shows, as one would expect, that low-carbohydrate diets are easier to comply with. This is indicated, first and foremost, by the evidence that the trend in the population has been in the direction of lowering fat and raising carbohydrates as recommended by DAA. The associated increase in obesity means that either these recommendations are not good or that they are hard to comply with, or both.
Most interesting, however, is that in a research setting, in studies where the low-fat diet and the low-carbohydrate diet are compared, the usual protocol is for people in the low‑fat group to be directed to consume an explicitly low calorie diet. They are usually required to eat what they were told. In the low‑carb group, in distinction, participants were allowed to eat anything that they wanted as long as they kept carbs low; even if you were to grant that the diets were really equal, which is more demanding and likely to have worse adherence? Which are you more likely to stick with? That the low-carb diet almost always does better in these circumstances is remarkable. When coupled with the constant discouragement from health agencies like DAA, the superior performance makes a low-carbohydrate diet a near miracle.
DAA: “Also, in the short term, low carbohydrate diets may be more effective in lowering high blood levels of triglycerides than low fat diets.”
Professor Feinman: Thou hast said it. But this is true in the long term as well. Any diminution is usually due to poor ability of the experimenter to encourage subjects to persist.
DAA: “In this era of a worldwide obesity epidemic it is important not to be distracted by quick fix solutions that appear in the popular press.”
Professor Feinman: This is a tip‑off that traditional diets fail (“Oh, no. Keep at it.”). In everything else that we do in life, we shoot for the quickest and most efficient method possible. We recognize that things go wrong and can take longer than we want but only Freudian psychoanalysis and conventional low‑calorie weight loss set out to go slowly by design. Failure is never a problem; you just have to keep doing it.
DAA: “Making a decision to adopt a healthy lifestyle is most effective when it is approached as a long-term change. Smaller changes that can be sustained are most likely to lead to improved health over time.”
Professor Feinman: This sounds good but it is exactly “a healthy lifestyle” that experts have been unable to define. Those who counsel small changes will also point out how common it is for weight and other effects to be regained. Not surprising since small changes over time are discouraging. Smaller changes are never sustained. It is success that encourages persistence. The epidemics of obesity and diabetes that coincide with current diet recommendations tells you where you won’t find success.
DAA: “There is undisputed evidence that the best way to control body weight and excess fat is to balance energy intake with energy output. Choosing foods and an eating pattern that help you to reduce the amount of kilojoules or calories you eat, is the simple key to weight loss when combined with physical activity.”
Professor Feinman: Insofar as there is evidence, it is hotly disputed. The energy balance idea is absurd notwithstanding how often it is quoted. Kilojoules taken in are distributed among work, muscle synthesis, fat synthesis, heat, entropic changes, and reorganization of cell material. The ratio of fat synthesis to the total change is the efficiency (from the standpoint of weight gain). The idea that all metabolic processes have the same efficiency regardless of dietary nutrient distribution is not consistent with undisputed biochemical evidence and, therefore, the experimental exceptions, which, in humans, almost always favor carbohydrate restriction, are to be taken seriously.
Professor Feinman: In the end, the DAA offers the APD and other Australian citizens little guidance on low-carbohydrate diets beyond undocumented “concerns.”
DAA says: “All our information has been written by Accredited Practising Dietitians (APDs), and is reviewed regularly.
DAA says: “So you can be sure this is the most up-to-date and credible nutrition info around!”
Professor Feinman would appear to disagree.