Last updated on May 24th, 2017
An invited, extensive review of experimental studies published in the June 2011 issue of the journal Nutrition in Clinical Practice (vol. 26, no. 3) argues that it is “time to embrace” low-carb diets “as a viable option” in the battle against diabetes, heart disease and obesity, and concludes that “the shift in metabolism that occurs on a LC [low-carbohydrate] diet heralds a shift in our current dietary paradigm.”
An abstract of the review is freely available online. The following account is based on my reading of the complete article.
The article entitled “Low-Carbohydrate Diet Review: Shifting the Paradigm” was authored by Adele H. Hite, MAT; Valerie Goldstein Berkowitz, MS, RD, CDE; and Keith Berkowitz, MD, MBA, and bases its conclusions on 87 published sources about LC diets, starting with Jean Brillat-Savarin’s The Physiology of Taste (1825). The main focus is on experimental studies conducted in recent decades.
The authors define an “LC” diet as one in which the subject consumes between 30 and 130 grams of carbohydrates per day, and a “VLCK” (very low-carbohydrate ketogenic) diet as one in which the subject consumes less than 30 grams of carbs per day. They define an “LF” (low-fat) diet as one in which the subject obtains only 10-15% of daily calories from fat.
They find that an LC diet is a viable way to achieve the widely held dietary goals of increasing the consumption of vegetables and decreasing the consumption of junk food. At the same time, they conclude, reducing carbohydrate consumption can improve glucose control and insulin response, and cardiovascular risk factors. Finally, people on LC diets are able to lose weight by “reducing calorie intake without hunger.” (I will personally testify to that last point!)
The authors reject several “clinical myths” regarding restricted carbohydrate diets.
The first is the myth that high protein consumption will damage the kidneys. The authors note that LC diets are not necessarily high protein diets; perhaps more importantly, it has been established that higher protein diets do not harm healthy kidneys.
The second myth is that fiber intake will fall off in an LC diet, given that many Americans get their fiber from “white flour and potatoes.” The authors respond that most LC dieters increase their consumption of green leafy vegetables, which are a much healthier source of fiber than white flour and potatoes.
The third myth is that LC diets replace healthy carbs with dangerous saturated fat. The authors cite recent research that shows replacing carbs with saturated fat “is, if anything, beneficial for risk reduction.” They also point out that large-scale population studies have failed to demonstrated a link between the consumption of saturated fat and heart disease.
The most carb-restrictive VLCK diets (such as the induction phase of Atkins) are safe; the authors say there may be some people for whom VLCK diets “may not be appropriate,” but even those people may benefit from reducing carbohydrates. Indeed, while the authors view the VLCK diet as a valuable short-term therapeutic approach, they view a more flexible LC approach as a useful “long-term dietary pattern” for most people.
I don’t know much about the journal Nutrition in Clinical Practice in which this review appeared, beyond that it has an impressive title, is in its 26th volume, and is apparently a publication of the American Society for Parenternal and Enteral Nutrition — whatever that is. Nevertheless, it is exciting and encouraging to see a pro-low-carb article based on a sweeping review of the scientific literature appearing in an academic/clinical journal. The facts and arguments given, the conclusions reached, will be familiar to readers of popular low-carb diet books, the low-carb blogs, and the work of Gary Taubes. But it is the setting that is different here. The tone and approach are academic: careful, precise, and a bit dry. The message, though, is clear and electric. Let us hope that the authors are right that a “paradigm shift” is under way!