Impact of Ketogenic Diet on Body Composition during Resistance Training among Untrained Individuals

Abstract

Background: Resistance training (RT) has been established as the most efficient approach for lean body mass maintenance required for preserving a sufficiently high metabolism during weight loss. Objective: This study aimed to evaluate the impacts of the ketogenic diet (KD) and regular diet (RE) in combination with 8-week resistance exercise (RT), on body weight, body fat mass (BFM), and lean body mass (LBM) of untrained individuals. Methods: Twenty untrained participants were randomly assigned to the RE+RT and KD+RT as control and experimental groups, respectively. Sixty to ninety minutes of diversified resistance exercise were performed by both groups, three sessions weekly, and diet was self-administered with a recommended daily energy and protein intakes. Body composition was measured using a Bioelectrical Impedance Analyzer. One-way Analysis of Covariance (ANCOVA) was applied to analyze the data. Results: The results showed a greater post-intervention adjusted mean for body weight and LBM in the normal dietary group in comparison with the experimental group. After controlling for baseline measurements, there was a statistically significant difference in body weight (p < .0005) and BFM (p =.001) between groups. Conclusion: Resistance training along with a ketogenic diet may decrease BFM without notable changes in LBM, whilst RT on a normal diet might increase LBM without remarkably influencing BFM.

The Effects of a Ketogenic Diet on Anthropometric Parameters, Metabolic Adaptation, and Physical Fitness Performance in Amateur Endurance Athletes: A Systematic Review

“…The difference in the magnitude of these changes could be altered, in part, by the different caloric intake strategies between studies and the amplitude of the restriction in the intake of CH (Table 1). This may explain that studies with daily calorie restriction of CH lower than 5% reported greater losses of fat mass (16,22,29). Nonetheless, these data provide strong evidence that combining LCHF dietary strategies with regular resistance training can help you lose body weight, with the same guarantees as any other proven nutritional planning (3,21).…”

“…Finally, in 6 of the studies that analyzed anthropometric parameters, FFM was not monitored, or no significant effects were observed. In the remaining 5 articles, significant decreases in FFM were identified, averaging a value of 22.88% (8,11,16,18,46).…”

“…Eleven of the 14 articles reviewed collected results on anthropometric parameters in the group that followed a KD. The methods for calculating body composition were varied, with a clear predominance of electrical bioimpedance (8,16,18,36,43), followed by the use of dual X-ray absorptiometry (29,46), digital column scale (22), and skinfolds (with a coefficient of variation of 3.8%) (40). Nine articles identified an average reduction of 4.17% in body weight.…”

“…In the studies that monitored the percentage of fat mass (8,11,16,18,22,29,36,43,46), it was observed that the decreases in this parameter harmonized with the rate of body weight loss, whereas the FFM did not change. Therefore, a KD with adequate planning and control mechanisms can favor an optimization of running economy in endurance sports (14,21), at least at the biomechanical level.…”

“…Aware of the potential of KDs on changes in body composition and metabolism, a wide variety of studies have tried to analyze the impact it would have if combined with endurance sports. Some authors have reported positive adaptations in body composition, because of a reduction in fat mass (16,28) and maintenance of fat-free mass (FFM) (23). This factor is not the only relevant fact for economy of aerobic effort (14), but also to avoid fluctuations in body weight (10,24).…”