Protein requirements in male adolescent soccer players

Abstract

Few investigations have studied protein metabolism in children and adolescent athletes which makes difficult the assessment of daily recommended dietary protein allowances in this population. The problematic in paediatric competitors is the determination of additional protein needs resulting from intensive physical training. The aim of this investigation was to determine protein requirement in 14-year-old male adolescent soccer players. Healthy male adolescent soccer players (N = 11, 13.8 +/- 0.1 year) participated in a short term repeated nitrogen balance study. Diets were designed to provide proteins at three levels: 1.4, 1.2 and 1.0 g protein per kg body weight (BW). Nutrient and energy intakes were assessed from 4 day food records corresponding to 4 day training periods during 3 weeks. Urine was collected during four consecutive days and analysed for nitrogen. The nitrogen balances were calculated from mean daily protein intake, mean urinary nitrogen excretion and estimated faecal and integumental nitrogen losses. Nitrogen balance increased with both protein intake and energy balance. At energy equilibrium, the daily protein intake needed to balance nitrogen losses was 1.04 g kg(-1) day(-1). This corresponds to an estimated average requirement (EAR) for protein of 1.20 g kg(-1) day(-1) and a recommended daily allowance (RDA) of 1.40 g kg(-1) day(-1) assuming a daily nitrogen deposition of 11 mg kg(-1). The results of the present study suggest that the protein requirements of 14-year-old male athletes are above the RDA for non-active male adolescents.

Nutrition for Female Soccer Players—Recommendations

“…In her work, Dolins indicated that, for physically active women, a dose of 1.2 g of protein/kg body mass/day is sufficient to maximize sporting achievements [53]. Boisseau et al stated that the Estimated Average Requirement (EAR) for football players should be 1.2 g/kg body mass/day, while the Recommended Dietary Allowances (RDA) is 1.4 g/kg body mass/day [54]. Although most studies and recommendations have referred to men or are targeted at athletes as a whole, protein recommendations are adequate for both men and women who train football [55].…”

Nutrient Intake and Food Habits of Soccer Players: Analyzing the Correlates of Eating Practice

“…To the best of our knowledge, only two studies have assessed this parameter by determining the nitrogen balance of adolescent male soccer players [31,32]. Those authors concluded that the protein requirements of these adolescents were above the recommended daily allowance of non-active counterparts, and reported a positive nitrogen balance from a mean protein intake of 1.57 g/kg BM.…”

“…The objectives of these guidelines are to optimize performance during training and competition, improve and accelerate recovery, achieve and maintain an optimal body weight and physical condition, and minimize the risk of injury and illness [31,32,33,34,35,36,37]. Recommended macronutrient intake has traditionally been expressed as a percentage of total energy intake (% energy).…”

Dietary Acid-Base Balance in Adolescent Sprint Athletes: A Follow-up Study

“…Boisseau et al . [13] conducted a nitrogen balance study on a group of adolescent soccer players and reported a protein need of 1.4 g/kg·day. Daily recovery and fuel needs for athletes with a moderate volume exercise program requires a carbohydrate intake of 5 to 7 g/kg·body mass [14].…”