Pediatric sports nutrition: an update

Nutrition for Children and Adolescents Who Practice Sport: A Narrative Review

At a developmental age, adequate physical activity is fundamental to overall health and well-being and preventing obesity. Moreover, establishing active behavior can help children and adolescents meet their growth and neurodevelopmental goals. Nutritional requirements vary according to intensity, frequency, and practiced physical activity or sport; therefore, pediatricians should give children and adolescents and their families adequate counseling, avoiding both nutrient deficiencies and excessive or inadequate supplement intake. The focus should be not only on sports performance but also on the child's well-being, growth, and neurodevelopment. Our narrative review aims to discuss the nutritional needs of children and adolescents who practice physical activity, non-competitive sports activity, and elite sports activity while also analyzing the role of food supplements and the risk of eating disorders within this category of subjects.

Primary Care Considerations for the Pediatric Endurance Athlete

PURPOSE OF REVIEW

This study aimed to provide an overview of some of the medical concerns surrounding the care of the pediatric endurance athletes and add to the limited literature specific to the pediatric endurance athlete.

RECENT FINDINGS

Endurance athletes are at risk for overtraining, relative energy deficiency in sport (RED-S), overuse injuries, nutritional deficiencies, and sleep dysfunction. Youth runners and female endurance athletes are particularly high-risk populations for RED-S; nutritional deficiencies and their care should involve thoughtful mitigation of modifiable risk factors. The growing endurance athlete may experience slightly different cardiac adaptations than the adult endurance athlete with the long-term implications of these changes still unclear. Endurance sports are common among youth athletes. Multidisciplinary care that includes screening and early intervention for high-risk areas is critical to optimize their care and promote, safe lifelong sport participation.

Nutritional Considerations for Sport Participation in Children and Adolescents With Obesity

There is a high prevalence of children with obesity who are participating in sports. Appropriate nutritional considerations are important to optimize health and training adaptations. This review focuses on macronutrient recommendations and their effect on weight management and/or benefits for athletic training for children ages 5 to 18 years. Equal distribution of protein intake throughout the day (~25-30 g/meal) and during postexercise recovery is recommended. Special attention should be given to increasing protein intake during breakfast because it is often the meal with the least protein intake. Both postexercise recommendations for protein (~0.3 g/kg of body weight) and carbohydrate (~1.0-1.2 g/kg/h) were not determined in children with obesity, and require future verification. Individual carbohydrate needs of training to meet fuel costs are recommended, but ~200 to 500 g/day of carbohydrate may be required depending on a child's level of sport participation and competition. Fat intake should follow general recommendations to meet the accepted macronutrient distribution range in children (25% to 35%) and reduce saturated fat intake. No evidence suggests that additional dietary fat modifications would improve training adaptations in children. Longitudinal studies are required to further our understanding of age and sex effects and confirm the appropriate quantity of macronutrients for active children with obesity.

Nutritional Considerations for Performance in Young Athletes

Nutrition is an integral component to any athletes training and performance program. In adults the balance between energy intake and energy demands is crucial in training, recovery, and performance. In young athletes the demands for training and performance remain but should be a secondary focus behind the demands associated with maintaining the proper growth and maturation. Research interventions imposing significant physiological loads and diet manipulation are limited in youth due to the ethical considerations related to potential negative impacts on the growth and maturation processes associated with younger individuals. This necessary limitation results in practitioners providing nutritional guidance to young athletes to rely on exercise nutrition recommendations intended for adults. While many of the recommendations can appropriately be repurposed for the younger athlete attention needs to be taken towards the differences in metabolic needs and physiological differences.

Sports Nutrition Advice for Adolescent Athletes

Adolescents participating in sport have high demands for nutritional adequacy to meet their needs for growth, development, wellness and athletics. Nutritional risk can be quite high in this population due to their unique needs, low access to credible information and nutrition professionals, and misinformation in the media and marketplace specifically targeting athletes. Physicians and other health professionals have an opportunity to communicate nutrition facts and make evidence-based recommendations about healthy eating in the setting of their ongoing interactions with adolescent athletes and their families. The purpose of this review is to describe the nutritional needs of adolescents participating in sport and highlight the potential for nutritional risk. Endorsed by professional organizations, our recommendations emphasize a balanced eating pattern that includes a wide variety of fresh, minimally processed whole foods. Our approach is to empower and teach adolescents to take responsibility for planning, preparing, and providing themselves consistent access to foods and fluids that deliver nutrients needed for proper fueling and recovery. Specific talking points that health professionals can use in brief interactions with patients and families are provided to endorse key behavioral strategies that young athletes can adopt to achieve peak athletic performance and optimal nutritional status.

Hydration status and fluid intake of urban, underprivileged South African male adolescent soccer players during training

Background

Poor hydration compromises performance and heightens the risk of heat stress which adolescents are particularly susceptible to as they produce comparatively larger amount of metabolic heat during exercise. This study determined the hydration status and fluid intake of socio-economically disadvantaged, male adolescent soccer players during training.

Methods

A pilot study was conducted among 79 soccer players (mean age 15.9 ± 0.8 years; mean BMI 20.2 ± 2.1 kg/m²). Hydration status was determined before and after two training sessions, using both urine specific gravity and percent loss of body weight. The type and amount of fluid consumed was assessed during training. A self-administered questionnaire was used to determine the players’ knowledge regarding fluid and carbohydrate requirements for soccer training.

Results

Players were at risk of developing heat illness during six of the 14 training sessions (60 - 90 minutes in length). Although on average players were slightly dehydrated (1.023 ± 0.006 g/ml) before and after (1.024 ± 0.007 g/ml) training, some were extremely dehydrated before (24%) and after (27%) training. Conversely some were extremely hyperhydrated before (3%) and after training (6%). The mean percent loss of body weight was 0.7 ± 0.7%.

The majority did not consume fluid during the first (57.0%) and second (70.9%) training sessions. An average of 216.0 ± 140.0 ml of fluid was consumed during both training sessions. The majority (41.8%) consumed water, while a few (5.1%) consumed pure fruit juice. More than 90% stated that water was the most appropriate fluid to consume before, during and after training. Very few (5.0%) correctly stated that carbohydrate should be consumed before, during and after training.

Conclusions

Approximately a quarter were severely dehydrated. Many did not drink or drank insufficient amounts. The players’ beliefs regarding the importance of fluid and carbohydrate consumption did not correspond with their practices. A nutrition education programme is needed to educate players on the importance of fluid and carbohydrate to prevent dehydration and ensure appropriate carbohydrate intake.

Body fat measurements in elite adolescent volleyball players: correlation between skinfold thickness, bioelectrical impedance analysis, air-displacement plethysmography, and body mass index percentiles

BACKGROUND

Determination of body composition is an essential parameter in training athletes because low fat-muscle ratio might improve physical performance in many types of sports. Since training is often conducted in the field, it is important to determine whether simple field measurements of body composition assessment correlate with laboratory measurements.

OBJECTIVE

Examine the correlation of body fat content as measured using skinfold thicknesses (SF), air-displacement plethysmography (BOD POD), bioelectrical impedance analysis (BIA) and body mass index (BMI) age and gender adjusted percentiles.

METHOD

Body mass as measured by SF, BOD POD, BIA, and BMI percentiles were examined in 29 elite, national team level, male and female volleyball players (age range 13 to 18) at the beginning of the training season.

RESULTS

Body fat percent measured by SF, BIA and BOD POD were highly positively correlated (r > 0.83). Measurements of body fat by SF, BIA and BOD POD were weakly correlated with BMI percentiles (r < 0.45).

CONCLUSIONS

Results suggest that BMI percentile is not a good measure for body fat in adolescent elite male and female volleyball players. SF and measurements of body composition by BIA and BOD POD are essentially interchangeable.

Hormonal and metabolic effects of nutrition in athletes

Competitive sport and strenuous physical activity make demands on our body above the usual physiological range. Measurable muscle damage and accumulation of metabolic products cause pain and other effects that can be demonstrated. From the medical point of view we have to provide athletes with adequate nutrients and energy for the maintenance of homeostasis and to cover their higher energetic and nutritional needs as compared to sedentary people. Some athletes may need supplements to replace essential nutrients missing from their regular (especially if unbalanced) diet, or to restore special needs, such as fluids and salts, while exercising in extreme climatic conditions. Overload of additives is frequent in both professional and amateur athletes. Very often, the proposed mechanism for the rationale of using these additives, 'supplements' or 'ergogenic compounds', is related to their possible effect on the endocrine-metabolic system, in many cases without solid evidence-based research. Yet it needs to be remembered that there is still disagreement on what are the required physiological needs of athletes for amino acids and other supplements. Different surveys on the use of supplements report that 40-60% of athletes take food additives, and the numbers are rapidly increasing. A more alarming fact is that about 50% of the recommendations to use these supplements come from non-professional people. Since some additives may change the endocrine and metabolic homeostasis in an unexpected way--as an extreme example of close to 50 deaths reported from the use of L-tryptophan supplements--it is important to study carefully the effects of additives given to athletes, and to increase awareness of the lack of knowledge in this field.