Effect of an 8-week free pre-prepared ketogenic diet and prescribed exercise on fitness, body composition, and blood lipid profile in overweight and obese individuals

INTRODUCTION: Low-carbohydrate diets have become widely known as one of the most effective methods of obesity treatment and weight management (Ebbeling et al., 2018). Whilst evidence support that a successful treatment for overweight and obese adults requires a combination of lifestyle alterations, including daily dietary intake and physical activity (Miller et al., 1997), data are limited regarding the combined effect of exercise and low-carbohydrate diet on metabolic parameters in this population. Therefore, the objective of the current study was to compare the short-term effects of the ‘THR1VE’ protocol (combined effect of commercially pre-prepared meals and structured exercise program) compared to standard dietary guidelines with a structured exercise program on body composition, cardio respiratory fitness and blood lipid biomarker changes.METHODS: This was a randomised controlled trial consisting of two conditions. Over an eight week period, participants in the experimentalcondition (n = 33; 35.3 years of age; BMI 29.8 kg.m-2) were provided with low-carbohydrate pre-prepared meals and participated on a prescribed supervised exercise program. Participants in the control condition (n = 31; 34.2 years of age; BMI 31.2 kg.m-2) were provided with dietary guidelines as developed by the Australian Government (www.eatforhealth.gov.au) and followed the same supervised exercise program. Measurements of cardio respiratory fitness (VO2peak), body composition (DEXA), and blood lipid biomarkerswere performed before and after the 8 week intervention.RESULTS: Baseline characteristics for VO2peak, body composition and blood biomarkers were similar between groups (P>.05). Both groups demonstrated improvements in body composition and blood lipids profile compared to baseline (P>.05).The experimental condition demonstrated significantly greater increase in VO2peak and decrease in Fat Mass Index and blood glucose levels compared to the control group (P < .05).CONCLUSION: Overall, participation in the trial was beneficial for all the participants in terms of cardio respiratory fitness, body composition,and blood lipids profile. However, those in the experimental condition following a low-carbohydrate diet achieved additional benefits in terms of improved fitness, reduced Fat Mass Index, and lower blood glucose levels. Our results are the first which provide some support that a low-carbohydrate diet in combination with a prescribed exercise regime can result in improved health outcomes for overweight and obese individuals.Ebbeling, C.B., Feldman, H.A., Klein, G.L., Wong, J.M.W., Bielak, L., Stltz, S.K., et al. (2018). Effect of a low carbohydrate diet on energy expenditure during weight loss maintenance: Randomized trial. BMJ, 363, 1-14.Miller, W.C., Koceja, D.M., &amp; Hamilton, E.J. (1997). A meta-analysis of the past 25 years of weight loss research using diet, exercise or diet plus exercise intervention. Int J Obesity, 21, 941-947