NEW ORLEANS — Prior research supports the effectiveness of a Ketogenic diet (KD) – based on a reduced carbohydrate intake (less than 30 grams per day or 5% of total energy intake), high fat intake, with adequate protein intake (0.9 grams per kilogram daily) – to facilitate weight loss, improve some metabolic disorders, cardiovascular disease, and type 2 diabetes - under medical supervision.
The KD diet works via ketogenesis, which starts in the liver and is facilitated through the creation of energy in the form of ketone bodies that can be effectively used by other tissues as an energy source via the Krebs cycle. After four-to-seven days on the KD, the main energy source is through lipolysis – the breakdown of adipose fatty acids. In short, fat as fuel.
New research, “Effects of Two Months of Very Low Carbohydrate Ketogenic Diet on Body composition, Muscle Strength, Muscle Area, and Blood Parameters in Competitive Body Builders,” which appeared in the January 2021, online issue of the journal Nutrients, tested the outcome of a KD diet on nineteen experienced, male body builders (BB) between the ages of 20 to 40 who were allocated either to a KD diet or allocated to a control group who followed a western-type diet (WD).
The subjects, after exclusion criteria, were assessed pre and post in this randomized study by blood sampling, after an overnight fast, body composition attained by Bioelectrical Impedance Analysis, metabolic studies (resting energy expenditure and quotient), and muscle strength.
The caloric intake of the dietary patterns provided, commented the Italian study investigators, was calculated by assigning an energy expenditure of 45 kcal/kg of muscle mass, while the protein intake was maintained at 2.5 g/kg/body weight.
The two protocols, as noted in the study, differed in the distribution of fats and carbohydrates; the latter were kept below 5% daily (less than 50 g/day) in the KD group while they represented 55% of the caloric intake in the WD group.
The researchers found that, “a KD diet may represent an adequate dietary approach for BB athletes. Despite the lack of hypertrophic (increase in muscle mass) response in the KD group, muscle mass was maintained, a phenomenon that often does not occur during low-calorie diets. Similarly, although the time of year was not the one that athletes usually dedicate to training for fat loss (“cutting”), KD proved to be a good strategy to reduce body fat.”
It was also referenced that, “KD is not a regime to be followed lightly and independently but requires the presence of a professional; in these circumstances KD represents a fundamental tool in the nutritionist’s baggage to face various conditions and needs, including those of sports.”
One caveat that was reported, and something I’ve been concerned about, is the potential loss of muscle mass while on a protracted KD diet. “KD may be used during body building preparation for health and leaning purposes, but with the caution that hypertrophic (muscle growth) muscle response could be blunted,” as concluded by the investigators.
If you’d like to read this study and much more, check out maxwellnutrition.com.