摘要：Background and Study Aim: One of the strategies for rapid weight loss among fighting athletes is calorie restriction with consequent
reduction of carbohydrate, which despite its efficacy has been an area of controversy. This study aim is the
effects of a low carbohydrate diet on body composition, hormonal profiles and performance task in Brazilian
jiu-jitsu (BJJ) athletes.
Material and Methods: We performed a clinical study of which 18 BJJ athletes were randomised into two groups: a) low carbohydrate (L-CHO
2-3g/kg/day) and b) adequate carbohydrate (A-CHO 4-6g/kg/day). The nutritional status, body composition,
hormonal profile (T3, T4, free-T4, thyroid stimulant hormone (TSH), insulin, cortisol and testosterone), muscle
power of upper and lower limbs, anaerobic fatigue index and aerobic endurance were assessed before and
after 30-days of nutritional intervention. Approved our protocol and we recorded the study in Clinical Trials
Registry (REBEC –RBR-76cd72).
Results: Regardless of the group, 88.9% achieved >3% of a weight loss and a decrement of body fat (>1.6%), however,
A-CHO presented a significative loss of lean body mass (∆ =−3.9 kg). The L-CHO decrease de waist (∆ = −3.5
cm; p = 0.005) and hip circumferences (∆=-2.0 cm; p = 0.009). The L-CHO group increased the blood TSH
(∆ = 0.6; p = 0.046) and T4 (∆ = 0.6; p<0.033) and decrease insulin concentration (∆ = −2.9; p = 0.009).
Conclusions: The main findings showed differences between low and adequate carbohydrate diet evaluated after
30-days of intervention. Both groups reduced the daily intake of total calories and lipids, and gravity of the
urine was remained hydrated before and after the nutritional intervention. After 30 days of training plus low
carbohydrate diet, athletes preserved the lean body mass, reducing hostility, the waist and hip circumferences.
Furthermore, insulin and thyroid hormones levels improved after the diet with low carbohydrates.
关键词：caloric restriction ; carbohydrate ; combat sports ; weight loss ; low carbohydrate ; nutritional status
