By Dr. Amanda Torres, RD - Sports Nutritionist
Published: [Date] • 10 min read
In collaboration with Dr. Kevin Martinez, MD - Pediatric Sports Medicine
"My 8-year-old plays soccer three times a week and seems exhausted all the time. She's also getting sick more often since she started playing competitively. Could her nutrition be the problem?"
This question comes up frequently in my sports nutrition practice. Many parents assume that if their child eats a "normal healthy diet," that's sufficient regardless of activity level. But active children—especially those training regularly—have significantly different nutritional needs than their sedentary peers.
Understanding these differences can mean the difference between a thriving young athlete and one who struggles with fatigue, frequent illness, and poor performance.
Active vs. Sedentary: The Nutritional Divide
Children who exercise regularly have markedly different nutritional requirements than those who don't.
Caloric Needs Can Double
Active children may need 1.5-2 times more calories than sedentary children of the same age.
Baseline caloric needs by age:
- Ages 4-6: 1,400-1,600 calories (sedentary) vs. 1,800-2,200 calories (very active)
- Ages 7-10: 1,600-2,000 calories (sedentary) vs. 2,200-2,800 calories (very active)
- Ages 11-14: 1,800-2,200 calories (sedentary) vs. 2,500-3,200 calories (very active)
Signs your active child needs more calories:
- Constant hunger, even after meals
- Weight loss or failure to grow appropriately
- Fatigue during or after activities
- Decreased performance despite training
- Frequent mood swings or irritability
- Getting sick more often than peers
Macronutrient Requirements Shift
The balance of carbohydrates, protein, and fat changes with activity level.
Carbohydrate needs increase dramatically:
- Sedentary children: 45-50% of calories from carbs
- Active children: 55-65% of calories from carbs
- Young athletes: Up to 70% during heavy training periods
Protein needs are higher:
- Sedentary children: 0.8-1.0g per kg body weight
- Active children: 1.2-1.6g per kg body weight
- Strength-training youth: Up to 2.0g per kg body weight
Fat remains important:
- Should not drop below 25% of total calories
- Essential for hormone production and nutrient absorption
- Provides sustained energy for longer activities
Micronutrient Demands Increase
Active children deplete vitamins and minerals faster than sedentary children.
Iron needs are significantly higher:
- Loss through sweat, especially in endurance activities
- Increased red blood cell production from training
- Girls entering puberty have additional iron loss from menstruation
- Iron deficiency is the most common deficiency in young athletes
B-vitamin requirements increase:
- Involved in energy metabolism
- Depleted more rapidly during exercise
- Especially important: B1 (thiamine), B2 (riboflavin), B6, B12
Antioxidant needs are elevated:
- Vitamin C and E help combat exercise-induced oxidative stress
- Support immune function, which can be suppressed by intense training
- Help with muscle recovery and tissue repair
Hydration: The Make-or-Break Factor
Dehydration is the fastest way to sabotage young athletes' performance and health.
Why Children Are More Vulnerable to Dehydration
Children have several physiological differences that increase dehydration risk:
Higher surface area to body weight ratio:
- Lose heat (and water) more rapidly than adults
- Sweat more relative to their body size
- Less efficient at cooling themselves
Immature thirst mechanisms:
- Don't feel thirsty until already dehydrated
- Often ignore thirst during exciting activities
- May not drink enough even when water is available
Different sweat composition:
- Lose more sodium relative to water than adults
- May need electrolyte replacement sooner than adults
- Individual variation in sweat rate and composition is huge
Hydration Guidelines That Actually Work
Pre-Activity Hydration:
- 2-3 hours before: 16-20 oz (2-2.5 cups) of fluid
- 15-20 minutes before: 8-10 oz (1-1.25 cups) of fluid
- Best choices: Water for activities under 1 hour, diluted sports drinks for longer activities
During Activity:
- Every 15-20 minutes: 4-6 oz (½-¾ cup) for children under 90 lbs
- Every 15-20 minutes: 6-8 oz (¾-1 cup) for children over 90 lbs
- Hot weather: Increase by 25-50%
- Best choices: Water for most activities, sports drinks for activities over 1 hour
Post-Activity Recovery:
- Immediate: 16-20 oz (2-2.5 cups) for every pound of weight lost during activity
- Within 2 hours: Replace 150% of fluid losses
- Best choices: Water plus a snack, or diluted sports drink
When Sports Drinks Are Actually Needed
Most youth sports don't require specialized beverages, but some situations do.
Water Is Sufficient For:
- Activities under 60 minutes
- Moderate intensity exercise
- Cool weather conditions
- Most recreational sports participation
Sports Drinks May Be Beneficial For:
- Activities over 60-90 minutes
- High-intensity exercise in hot weather
- Multiple games/events in one day
- Children who are heavy sweaters
- When appetite is poor after exercise
Making Smart Sports Drink Choices:
- Dilute commercial sports drinks by 50% for most children
- Look for 6-8% carbohydrate concentration (14-19g per 8 oz)
- Sodium content: 110-170mg per 8 oz
- Avoid: Energy drinks, high-caffeine beverages, drinks with artificial sweeteners
Pre-Activity Fueling Strategies
What children eat before exercise significantly affects their performance and comfort.
Timing Matters
3-4 hours before activity:
- Full meal with carbohydrates, moderate protein, low fat and fiber
- Examples: Oatmeal with banana and a small amount of nut butter; whole grain pasta with lean meat and vegetables
1-2 hours before activity:
- Small snack emphasizing easily digestible carbohydrates
- Examples: Banana with small amount of honey; whole grain toast with jam; sports drink and crackers
30-60 minutes before activity:
- Liquid or very easily digestible carbohydrates
- Examples: Diluted fruit juice; sports drink; banana
15-30 minutes before activity:
- Only if needed for very long activities
- Examples: Few sips of sports drink; small amount of honey
Foods to Avoid Before Activity
High-fat foods: Take too long to digest, can cause stomach upset High-fiber foods: May cause digestive discomfort during exercise Large amounts of protein: Require significant energy to digest Unfamiliar foods: Save new foods for non-competition days Excessive fluids: Can cause bloating and discomfort
During-Activity Nutrition for Long Events
For activities lasting more than 60-90 minutes, fuel replacement becomes important.
Carbohydrate Guidelines:
- 30-60g per hour for activities over 1 hour
- Start early: Begin within first 30 minutes
- Consistent intake: Every 15-20 minutes rather than large amounts at once
Practical Options:
- Sports drinks: 4-6 oz every 15-20 minutes
- Fresh fruit: Banana, grapes, orange slices
- Easy-to-digest snacks: Graham crackers, pretzels, dried fruit
- Homemade options: Diluted fruit juice with pinch of salt
Post-Activity Recovery: The Critical Window
What happens in the first 30-120 minutes after exercise determines how well children recover.
The Recovery Window
Immediate (0-30 minutes):
- Primary focus: Fluid replacement
- Secondary focus: Begin carbohydrate replacement
- Examples: Water plus fresh fruit; chocolate milk; diluted sports drink
30-120 minutes:
- Carbohydrate replacement: 1-1.5g per kg body weight
- Protein addition: 0.25-0.5g per kg body weight
- Examples: Peanut butter and jelly sandwich with milk; Greek yogurt with berries and granola; turkey and cheese wrap with fruit
2-24 hours:
- Continue adequate nutrition: Don't skip meals after exercise
- Focus on whole foods: Balanced meals with all macronutrients
- Maintain hydration: Continue drinking throughout the day
Age-Specific Considerations
Young Children (Ages 4-8)
Developmental factors affecting nutrition:
- Shorter attention spans: May forget to eat or drink
- Smaller stomach capacity: Need frequent, smaller feedings
- Less developed thirst mechanism: Need reminders to drink
- Food neophobia: May reject new sports foods
Practical strategies:
- Visual reminders: Use colorful water bottles, set timers
- Familiar foods: Stick to foods they know and like
- Make it fun: Use fun cups, straws, ice cubes with fruit
- Parent responsibility: Adults must manage timing and amounts
Pre-Teens (Ages 9-12)
Developmental factors:
- Increased independence: Want to make own choices
- Peer influence: May copy teammates' eating habits
- Growth spurts: Appetite and needs change rapidly
- Increased competition: May put pressure on themselves
Practical strategies:
- Education: Teach them why nutrition matters for performance
- Involvement: Let them help plan pre-game meals and snacks
- Flexibility: Adjust portions based on growth and appetite
- Support: Help them resist peer pressure around poor food choices
Teenagers (Ages 13+)
Developmental factors:
- Body image concerns: May restrict calories inappropriately
- Busy schedules: May skip meals or rely on convenience foods
- Independence: Often responsible for own food choices
- Social pressures: Team dinners, social eating situations
Practical strategies:
- Performance focus: Emphasize how nutrition affects their goals
- Practical skills: Teach them to prepare their own healthy meals and snacks
- Body positive messaging: Focus on strength and performance, not appearance
- Professional support: Consider sports dietitian consultation for serious athletes
Common Nutrition Mistakes in Youth Sports
Mistake 1: Under-Fueling
The problem: Many young athletes don't eat enough to support their training Signs: Fatigue, frequent illness, poor performance, mood swings, growth delays Solution: Track intake for a few days, increase portions gradually, add healthy snacks
Mistake 2: Over-Hydrating with Plain Water
The problem: Drinking excessive plain water can dilute electrolytes Signs: Bloating, nausea, headache during long activities Solution: Use diluted sports drinks for activities over 1 hour, add electrolytes as needed
Mistake 3: Relying on Sports Products
The problem: Expensive sports foods often aren't better than whole foods Reality: Most young athletes can meet needs with regular food Solution: Use whole foods first, sports products only when necessary
Mistake 4: Ignoring Individual Differences
The problem: Assuming all children on a team have the same needs Reality: Body size, training load, sweat rate, and metabolism vary hugely Solution: Individualize approach based on child's specific needs and responses
Mistake 5: Focusing Only on Game Day
The problem: Good nutrition only around competitions Reality: Daily nutrition affects training quality and adaptation Solution: Emphasize consistent daily nutrition, not just performance times
Supplements for Young Athletes: When and What
Most young athletes can meet their needs through food, but some situations may warrant supplementation.
Generally Safe and Sometimes Beneficial:
Multivitamin with iron:
- When: Restrictive diets, frequent illness, confirmed deficiencies
- Dosing: Age-appropriate amounts, not megadoses
- Safety: Choose third-party tested products
Vitamin D:
- When: Limited sun exposure, northern climates, indoor sports
- Dosing: 600-1000 IU daily for most children
- Testing: Blood levels can guide appropriate dosing
Probiotics:
- When: Frequent digestive issues, antibiotic use, high stress periods
- Types: Multi-strain products with evidence in children
- Safety: Generally very safe with quality products
Sometimes Appropriate Under Professional Guidance:
Iron:
- When: Confirmed iron deficiency (blood test required)
- Caution: Too much iron is harmful; needs medical supervision
- Monitoring: Regular blood tests to assess effectiveness and safety
Electrolyte supplements:
- When: Heavy sweaters, multiple daily sessions, hot climates
- Types: Products designed for children, not adult formulations
- Alternatives: Often food-based options work just as well
Never Appropriate for Children:
- Protein powders (except specific medical conditions)
- Creatine (no safety data in children)
- Caffeine supplements (can affect developing nervous system)
- Weight loss supplements (can interfere with growth)
- "Performance enhancers" (unsafe and unnecessary)
Red Flags: When to Seek Professional Help
Concerning signs that warrant professional evaluation:
Growth and development issues:
- Weight loss or poor weight gain despite good appetite
- Linear growth slowing significantly
- Delayed puberty beyond normal variation
Performance and health problems:
- Declining performance despite consistent training
- Frequent injuries or slow healing
- Recurring illness or infections
- Chronic fatigue not resolved by rest
Psychological concerns:
- Obsessive food tracking or extreme dietary restriction
- Fear of certain foods or food groups
- Body image issues affecting food choices
- Signs of disordered eating patterns
Building Lifelong Healthy Habits
The goal isn't just optimizing current performance—it's teaching skills for lifelong health.
Teaching Self-Awareness:
- Help children notice how different foods affect their energy and performance
- Encourage them to tune into hunger, fullness, and thirst cues
- Teach them to recognize signs of under-fueling or dehydration
Developing Practical Skills:
- Involve them in meal planning and preparation
- Teach basic nutrition knowledge appropriate for their age
- Help them learn to make good choices in various situations (cafeteria, restaurants, team meals)
Maintaining Perspective:
- Emphasize that nutrition supports their goals, it doesn't define their worth
- Keep the focus on health and performance, not appearance
- Remember that childhood should include flexibility and enjoyment around food
Your Active Child Nutrition Action Plan
Week 1: Assessment
- Track your child's current intake for 3-7 days
- Note energy levels, mood, and performance patterns
- Assess current hydration habits
- Identify biggest gaps between needs and current intake
Week 2: Hydration Focus
- Establish pre-activity hydration routine
- Practice during-activity fluid intake (if activities are long enough)
- Implement post-activity recovery hydration
- Monitor urine color as hydration indicator
Week 3: Fueling Strategies
- Experiment with pre-activity meals and snacks
- Time eating to optimize energy and comfort
- Add post-activity recovery nutrition
- Increase overall caloric intake gradually if needed
Week 4: Fine-Tuning
- Adjust strategies based on what's working
- Address any ongoing issues (fatigue, poor recovery, etc.)
- Plan for upcoming competitions or intense training periods
- Consider professional consultation if concerns remain
The Bottom Line
Active children have significantly different nutritional needs than their sedentary peers, and meeting these needs can dramatically affect their health, performance, and enjoyment of sports.
Key takeaways:
- Caloric and fluid needs are much higher for active children
- Timing of nutrition around activities matters for performance and recovery
- Most nutritional needs can be met through whole foods rather than sports products
- Individual differences are huge—what works for one child may not work for another
- Professional guidance can be valuable for serious young athletes
Remember: The goal is supporting your child's current activities while building knowledge and habits that will serve them throughout their life. Focus on health and performance, maintain perspective, and don't forget that childhood should include joy around both food and physical activity.
Dr. Amanda Torres is a registered dietitian specializing in sports nutrition with 12+ years of experience working with young athletes. Dr. Kevin Martinez is a pediatric sports medicine physician.