Resistance training in overweight women on a ketogenic diet conserved lean body mass while reducing body fat

Abstract

BackgroundThe aim of the present study was to compare the effects of 10 weeks resistance training in combination with either a regular diet (Ex) or a low carbohydrate, ketogenic diet (Lc+Ex) in overweight women on body weight and body composition.Methods18 untrained women between 20 and 40 years with BMI ≥ 25 kg*m-2 were randomly assigned into the Ex or Lc+Ex group. Both groups performed 60-100 min of varied resistance exercise twice weekly. Dietary estimates were based on two 4-day weighed records. Body composition was estimated using Dual Energy X-ray Absorptiometry. Fasting blood samples were analyzed for total-, HDL- and LDL-cholesterol, triacylglycerols, and glucose.Results16 subjects were included in the analyses. Percentage of energy (En%) from carbohydrates, fat and protein was 6, 66, and 22 respectively in the (Lc+Ex) group and 41, 34, 17 in the Ex group. Mean weight change (pre-post) was -5.6 ± 2.6 kg in Lc+Ex; (p < 0.001) and 0.8 ± 1.5 kg in Ex; (p = 0.175). The Lc+Ex group lost 5.6 ± 2.9 kg of fat mass (p = 0.001) with no significant change in lean body mass (LBM), while the Ex group gained 1.6 ± 1.8 kg of LBM (p = 0.045) with no significant change in fat mass (p = 0.059). Fasting blood lipids and blood glucose were not significantly affected by the interventions.ConclusionResistance exercise in combination with a ketogenic diet may reduce body fat without significantly changing LBM, while resistance exercise on a regular diet may increase LBM in without significantly affecting fat mass. Fasting blood lipids do not seem to be negatively influenced by the combination of resistance exercise and a low carbohydrate diet.

The Ketogenic Diet and Sport

“…It is a form of dietary pattern that has been subject to intense scrutiny especially across the decades since the popularization of the Atkins diet and, apart from its positive effects on weight loss, the shortterm use of energy-sufficient KD has not been associated with any long-term health issues; the few symptoms such as fatigue and headaches disappear after a few days (22). Biochemical, physiological, and observational studies also provide good evidence that an actual KD (i.e., where adherence is checked) can lead to fat loss with little or no loss of muscle mass (13,25). Indeed, it is a common misconception that the KD intuitively is unsafe because it is a ''high-protein, highYsaturated fat'' diet.…”

Fat-Free Mass Changes During Ketogenic Diets and the Potential Role of Resistance Training

“…It is well established that resistance training can increase muscle mass and help mitigate loss of fat-free mass during weight loss (Ballor et al 1988;Delmonico & Lofgren, 2010;Stiegler & Cunliffe, 2006). Only two studies were located that have investigated whether combining resistance training with a ketogenic diet provides superior changes in body composition relative to other diets in combination with resistance training (Jabekk et al, 2010;Wood et al, 2012).…”

“…As detailed in Table 2, these studies were markedly different on a number of factors, including subject age and gender, frequency of strength training, exercise selection, sets and repetitions performed, and method of body composition assessment. Jabekk et al (2010) reported no change in fat-free mass in subjects following a resistance training program in combination with a ketogenic diet, and Wood et al (2012) reported a decrease. However, the results from Wood et al (2012) indicated that, without exercise, a ketogenic diet led to less fat-free mass loss than a low-fat diet and similar losses as compared to a low-fat diet plus resistance training.…”

“…However, the results from Wood et al (2012) indicated that, without exercise, a ketogenic diet led to less fat-free mass loss than a low-fat diet and similar losses as compared to a low-fat diet plus resistance training. The results of Jabekk et al (2010) could also be viewed as positive in regards to the efficacy of a ketogenic diet and resistance training because fat-free mass was not lost, while a relatively large amount of fat mass was lost (-5.6 ± 2.6 kg).…”

Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

“…A study in overweight women suggested that a LCHF diet in combination with resistance training reduced body weight and fat mass while maintaining lean body mass, whereas resistance training in combination with a regular higher-carbohydrate diet increased fat-free mass but maintained fat mass (Jabekk et al, 2010). These changes are at least partially due to reduced anti-lipolytic insulin action and protein-protective action of increased total and free thyroxine index after a LCHF diet (Volek et al, 2002).…”