Sports Nutrition for Young Athletes: What to Eat for Performance, Growth & Recovery (A Dietitian Guide)

Sports Nutrition for Young Athletes: A Dietitan's Guide to Performance, Growth and Recovery

Adequate nutrition is fundamental to both optimal athletic performance and healthy development in young athletes. Unlike adults, young athletes are not only training and competing, but also undergoing rapid physical growth and maturation. As accredited sports dietitians, we see firsthand that adolescence has the highest nutrient requirements of any time across the lifespan.

One of the most common issues seen in youth sport nutrition is under-fuelling or an overreliance on supplements rather than whole foods. A balanced sports nutrition plan should prioritise sufficient energy intake, macronutrient distribution, micronutrient adequacy, and proper hydration to support both performance and long-term health.

Protein for Young Athletes

Protein is one of the most discussed topics in sports nutrition for young athletes, and one of the most misunderstood. Protein plays a central role in growth, tissue repair, and muscle development. When total energy needs are met, young athletes typically require around 1.5 grams of protein per kilogram of body weight per day. This intake supports periods of rapid growth while also compensating for amino acid losses during exercise.

However, total intake is only part of the picture. The timing and distribution of protein intake throughout the day significantly influences whole-body protein balance. Consuming protein at breakfast helps initiate a positive balance early in the day, while spreading intake evenly across meals every three to four hours allows for sustained muscle repair and growth. Research suggests that smaller, regular servings are more effective than large, infrequent intakes. Importantly, consuming protein well above requirements does not confer additional performance or developmental benefits and may prevent consumption of other important nutrients.

Carbohydrates: The Primary Fuel for Sport

Carbohydrates are the primary fuel source for training and competition. Young athletes involved in team sports, swimming, athletics, or gymnastics are particularly susceptible to fatigue if carbohydrate intake is inadequate, as they deplete glycogen stores more rapidly than adults. Without appropriate refuelling, performance declines and recovery is impaired.

During recovery post exercise, easily digestible carbohydrate drinks can support glycogen replenishment while also assisting with hydration (e.g. chocolate milk, sports drinks, fruit juice). Drinks containing fructose (e.g. fruit juice) or galactose (e.g. dairy) replenish fuel stores faster than glucose alone, making them particularly useful during short recovery windows between training sessions or competitions. Carbohydrate requirements should be adjusted to match training demands higher training days requiring additional carbohydrates for fuel. Wholegrain carbohydrates for slow-release energy should be prioritised in main meals, whilst fast-digesting carbohydrates should be utilised for pre-training snacks.

Dietary Fat: An Essential Nutrient

Dietary fat is an essential component of a young athlete's diet. It facilitates the absorption of fat-soluble vitamins, supports hormone production, and is a dense energy source. Vitamins A, D, E, and K rely on dietary fat for absorption, and fatty acids, omega-3 and omega-6 play important roles in inflammatory processes and cellular function. Current recommendations suggest that fat should comprise between 20 and 35 percent of total energy intake. Emphasis should be placed on whole food sources such as nuts, seeds, and oily fish to ensure adequate intake of essential fatty acids.

Iron Deficiency in Young Athletes

Iron deficiency is one of the most common nutritional concerns we address as sports dietitians working with young athletes. Iron is essential for oxygen transport and energy metabolism. Deficiency is relatively common, especially among female athletes, and can significantly reduce endurance and increase fatigue. Iron-rich foods include red meat, legumes, tofu, and fortified cereals. Absorption of dietary iron varies depending on its source, but can be enhanced by consuming vitamin C-rich foods alongside iron-containing meals.

Calcium and Vitamin D for Bone Health

Calcium and vitamin D are critical during adolescence a period characterised by rapid bone development. Calcium supports bone mineralisation, while vitamin D enhances calcium absorption and contributes to immune health. Requirements for calcium are highest during the adolescent growth spurt, yet many young athletes fail to meet recommended intakes. Recommended calcium intake for adolescents is 1,300 mg per day. In Sydney, vitamin D deficiency can still occur despite our sunny climate, particularly among those who train indoors or have limited sun exposure. These deficiencies can compromise bone health and increase the risk of injury if not addressed.

Hydration for Young Athletes

Hydration is another key determinant of performance that is often overlooked. Even mild dehydration can negatively impact endurance, cognitive function, and thermoregulation. Research indicates that a significant proportion of athletes begin training sessions already underhydrated. Maintaining fluid balance before, during, and after exercise is essential. As a general guide for young athletes:

• 250–500 mL 1 hour prior to exercise
• ~150 mL every 15 minutes during exercise
• 500 mL–1 L post-exercise, depending on sweat losses

Should Young Athletes Take Supplements?

A question we frequently hear in our Sydney dietitian clinic is: "Does my child need protein powder or supplements?" The short answer is: usually not. While some supplements are marketed for performance enhancement, most young athletes can meet their nutritional needs through a well-balanced diet. Protein supplements are generally unnecessary, as dietary intake is typically sufficient. Although certain supplements, such as creatine, have shown potential benefits in specific contexts, their use should only be considered under professional supervision due to the lack of long-term safety data in adolescents.

Energy Availability and RED-S in Young Athletes

Meeting overall energy requirements is the most important aspect of sports nutrition for young athletes. Energy intake must account for basal metabolic needs, physical activity, and growth. Because these factors fluctuate, estimating precise requirements can be challenging. The concept of energy availability provides a useful framework for understanding whether an athlete is adequately fuelled. When energy intake is insufficient relative to expenditure, a condition known as Relative Energy Deficiency in Sport (RED-S) may develop.

RED-S is associated with widespread physiological consequences, affecting metabolic function, hormonal balance, bone health, and immune capacity. It can also impair performance, leading to reduced strength, endurance, and concentration, as well as an increased risk of injury. Early recognition and appropriate nutritional intervention are essential to prevent long-term health consequences.

Sports Nutrition Support in Sydney

Ultimately, nutrition for young athletes should focus on consistency, balance, and adequacy rather than restriction or quick fixes. A food-first approach that prioritises whole, nutrient-dense options will best support both performance and development. By ensuring sufficient energy intake, optimising macronutrient distribution, maintaining hydration, and addressing micronutrient needs, young athletes can perform at their best while supporting lifelong health.