Low or Adequate Carbohydrate Diet and Aerobic Exercise Decrease Cardiometabolic Risk in Overweight Women: A Randomized Controlled Clinical Trial

Abstract

Aims: To evaluate the efficacy of a low carbohydrate diet on body composition and cardiometabolic markers in overweight women undergoing endurance physical training. Subjects/Methods: A randomized, controlled clinical trial included 24 overweight women, 8 of whom consumed low-calorie diets containing an adequate carbohydrate content, while 16 consumed a low carbohydrate diet. The women regularly performed semi-supervised physical exercise (walking/running) for 12 weeks. Body composition (weight, abdominal and hip circumferences) and cardiometabolic parameters were analyzed. Data were analyzed using a two-way analysis of variance with the Bonferroni post-hoc test. A p value < 0.05 indicated statistical significance. Results: After 12 weeks, both groups exhibited significant reductions (p < 0.05) in body mass (A-CHO: 9.86%; L-CHO: 8.48%), abdominal (A-CHO: 7.48%; L-CHO: 8.05%) and hip circumferences, fat percentage (A-CHO: 7.32%; L-CHO: 9.15%), and liver function marker levels (AST: A-CHO: 12.24%; L-CHO: 11.26%; ALT: A-CHO: 6.48%; L-CHO: 11.93%), as well as improved lipid profiles. However, no differences were observed in the anthropometric and biochemical variables regarding to the carbohydrate content (p > 0.05). Conclusion: The combination of a hypocaloric diets with jogging effectively promoted weight loss and improved cardiometabolic risk parameters, regardless of the carbohydrate content of the diet. Brazilian Clinical Trials Registry (Registration No. RBR5n9g5f). *Corresponding author: Marzo Edir da Silva Grigoletto, M.E., Center of Biological and Health Sciences, Department of Physical Education, Federal University of Sergipe, Cidade Universitária Prof. José Aloísio de Campos, Av. Marechal Rondon, s/n Jardim Rosa Elze, 49100-000, São Cristóvão, Sergipe, Brazil ISSN: 2469-5718 DOI: 10.23937/2469-5718/1510146 • Page 2 of 8 • Mendes-Netto et al. Int J Sports Exerc Med 2019, 5:146 effects, such as an improved body composition and cardiometabolic parameters, remains controversial. Therefore, we presumed that defining a dietary macronutrient distribution protocol would strengthen the nutrition strategies for overweight/obese patients, thus allowing greater control over their treatment and preventing deterioration of their conditions. This study aimed to evaluate the effects of dietary carbohydrate reduction on body composition and cardiometabolic markers in overweight women undergoing endurance physical training. Materials and Methods Sample This randomized controlled clinical trial included adult women enrolled from among the students, professors, and staff of the university. Although we identified 361 interested potential participants, only 106 met the inclusion criteria of an age between 18 and 59 years, sedentary status, body mass index between restriction (carbohydrate intake < 20 g/day or < 5% of the daily intake), unsatisfactory effects such as a lack of enthusiasm for physical activity, subsequent weight gain, and low adherence to dietary follow-up, have been observed [6,15-19]. Other studies have shown that compared with other types of diets, a reduction in dietary carbohydrate intake and corresponding increase in saturated fat intake could damage the cardiometabolic profile, leading to increases in the levels of markers such as low-density lipoprotein cholesterol [20]. In contrast, other studies have demonstrated improvements in the cardiometabolic condition, as indicated increased high-density lipoprotein cholesterol levels, decreased C-reactive protein levels, and increased adiponectin levels [12,13]. For adults, the Dietary Reference Intake for macronutrients suggests a minimum daily carbohydrate intake of 130 g per day and/or 45-65% of the total dietary energy intake [21]. Given this wide range, the minimum amount of carbohydrates required to confer positive Women under follow-up A-CHO (n=8) Women under follow-up L-CHO (n=16) Group with low dietary carbohydrate intake L-CHO (n=25) Eligible (Continuous training) (n=57) Excluded (n=250) Abandonment (n=5) Demonstration of interest in joining the program (n=361) Group with an adequate dietary carbohydrate intake A-CHO (n=32) Concluded the 12-week continuous exercise (n=22) Concluded the 12-week continuous exercise (n=19) ALLOCATION