Sports Nutrition for Kids & Teens

1. Sports Nutrition for Kids & Teens Leah Esplen, MSc (BPK) lesplen@sfu.ca

2. Why? • Kids and teens are not just smaller adults • They need enough energy and nutrients to sustain growth, development, repair and physical activity • There are periods of rapid growth and development during which needs increase even more • These growth spurts are driven by different mechanisms but the result is the same

3. Early Growth • Velocity ~ 5-15 cm/yr • Driven by Growth hormone (GH) and Insulin-like growth factor 1 (IGF-1) • Early growth spurt then deceleration • 2/3 of children have a growth spurt at age 7-8 • Increased growth velocity of legs rather than trunk

4. Pubescent Growth • Driven by sex steroids • Growth spurt results in an acceleration of trunk length growth velocity rather than legs • 15% of final height is attained • Girls start and attain PHV 2 years earlier than boys • 50-80% of the 1500g of the calcium that is accrued from birth to age 20 is from the 2-4 years of pubertal growth

5. Early and Pubertal Growth Open dots represent average length/height Closed dots represent bone mineralization Bass et al., 1999

6. Assessment • Food intake checklists • 24-hour food recall • An adequate diet provides enough energy for physical activity and to maintain weight over the short term • Weight gain should occur over the long term but increases in muscle mass and height also need to be taken into consideration.

7. Education • Familiarize them with Eating Well With Canada’s Food Guide • Allow them to help prepare meals and snacks • Prepare meals and snacks ahead of time • Talk to them about meal and snack timing • Choose one adventurous meal a week

8. Canada’s Guide to Healthy Eating

9. Meeting Nutritional Needs: Energy for Boys • 3-8 years • Estimated Energy Requirement (EER)= 88.5 – (61.9 * age) + Physical Activity Coefficient (PA) * {(26.7 * weight in kg) + (903 * height in m)} + 20 • 9-18 years • EER = 88.5 – (61.9 * age) + Physical Activity Coefficient (PA) * {(26.7 * weight in kg) + (903 * height in m)} + 25

10. Meeting Nutritional Needs: Energy for Girls • 3 – 8 years: • EER = 135.3 – (30.8 * age) + PA {(10 * weight in kg) + (934 * height in m)} + 20 • 9 – 18 years: • EER = 135.3 – (30.8 * age) + PA {(10 * weight in kg) + (934 * height in m)} + 25

11. Physical Activity Coefficients

12. Meeting Basic Nutritional Needs • Carbohydrate: 45-65% of Energy Intake • Fat: 25-35% • Omega-6 (linoleic): 5-10% • Omega-3 (alpha-linolenic): 0.6-1.2% • Protein: 10-30% • However, this gets a little more complicated when we are dealing with athletes

13. Meeting Nutritional Needs: Carbohydrate • Girls & boys 9-18 years: • 130g/day (minimum) • Athletes: • 7-10 g/kg/day with more CHO for activities that include higher intensity and volume. • Fibre • Girls 9-18 years: 26 g/day • Boys 9-13 years: 31 g/day, 14-18 years: 38 g/day

14. Meeting Nutritional Needs: Carbohydrate • Children & teens rely more on dietary sources of CHO than stored sources. • They also derive more of their energy from fat rather than carbohydrate during moderate intensity exercise and so produce less lactic acid than an adult would, ie. Higher lactate threshold • Children and teens can tolerate short bursts of activity, such as sprints, very well

15. Meeting Nutritional Needs: Fat • No specific recommendations for overall fat intake but… • Omega-6 (linoleic): • Males 9-13 -> AI = 12 g/day, 14-18 -> 16 g/day • Females 9-13 -> 10 g/day, 14-18 -> 11 g/day • Omega-3 (alpha-linolenic) • Males 9-13 -> 1.2 g/day, 14-18 -> 1.6 g/day • Females 9-13 -> 1.0 g/day, 14-18 -> 1.1 g/day

16. Meeting Nutritional Needs: Protein • Girls and Boys 9-13: 0.95 g/kg/day • Girls and Boys 14-18: 0.85 g/kg/day • Athletes may need up to 1.5 g/kg/day • So far, the dangers of excess protein have been associated with the source of protein. Animal sources of protein typically contain higher amounts of cholesterol and saturated fats. • High protein intake may be dangerous in people who have kidney issues.

17. Fluid Needs • Girls • 9-13 years -> 2.1 L/day • 14-18 years -> 2.3 L/day • Boys • 9-13 years -> 2.4 L/day • 14-18 years -> 3.3 L/day • Teach them to take a look after urinating, pale is perfect, dark is dangerous

18. Fluid Needs • If urine is dark, continue hydrating until it is pale • Rehydrate with plain water unless activity was continuous for over an hour • Guideline for young athletes: drink periodically until you’re not thirsty anymore, and then another few gulps (Bar-Or, 1995) • <10 yrs =125 mL beyond thirst, >10 yrs = 250 mL beyond thirst • Avoid vitamin waters and energy drinks!

19. Fluid Needs • Dangers of hypohydration vs. hyponatremia • Hypohydration – under-hydration, includes the classification ‘dehydration’ • Functional losses with only 10% dehydration • Hyponatremia – low blood electrolytes (sodium) • Presents very similarly to dehydration but involves swelling of the nerves – if suspected go immediately to ER and tell them the person was in the water.

20. Meeting Nutritional Requirements: Micronutrients • Generally speaking, since there is an increase in energy intake there will be a corresponding increase in micronutrient intake so there is no need for a supplement in the absence of disease or disorder • Some specific nutrients to watch for: calcium, iron & zinc

21. Meeting Nutritional Requirements: Micronutrients • Calcium: • Girls and boys 9-18 years -> 1300 mg/day • Iron: • Girls and boys 9-13 years -> 8 mg/day • Girls 14-18 years -> 15 mg/day • Boys 14-18 years -> 11 mg/day • Zinc: • Girls and boys 9-13 years -> 8 mg/day • Girls 14-18 years -> 9 mg/day • Boys 14-18 years -> 11 mg/day

22. Glycemic Index • Represents the speed in which glucose appears in the blood • High GI -> glucose appears very quickly • Low GI -> glucose is slowly released over time • Does NOT represent how much glucose (CHO) is actually in a food

23. Glycemic Index • Low GI foods are more sustaining whereas high GI foods allow for faster storage of glucose by the tissues (more dramatic insulin response) • The timing and content of pre & post exercise foods is important to an athlete’s performance

24. Timing & Content for Training • Eat a low GI breakfast 2-4 hours prior to training to help restore liver and muscle glycogen content. • If necessary, eat a medium GI snack in the hour before training. • If training for more than 60 minutes, include small high GI snacks and fluid.

25. Timing & Content for Training • After strenuous training, eat a snack composed of 1 g of protein for every 4 g of CHO. • Drink fluids as necessary. • Resume a regular meal pattern as soon as possible after training.

26. Timing & Content for Swim Meets • Eat a low GI snack at least an hour prior to warm-ups to help restore liver and muscle glycogen content. • After warm-ups, eat a low-medium GI breakfast – if event is less than an hour away, eat a medium GI snack and then have a medium-high GI breakfast right after the race. • If a snack is going to be eaten, it should be high GI and be accompanied by water

27. Timing & Content for Swim Meets • Lunch should be relatively small and eaten right after the last race before lunch time. During meets with a designated lunch break, a larger lunch can be eaten after the last pre-lunch race. • After the last race of the day, snacks with a 1:4 protein: CHO ratio and water should be consumed until parents can get off the deck and a regular meal pattern can be resumed. • Rest and repeat!

28. Examples of food • Low-GI breakfast: fruit smoothie with flax seeds, spinach and tofu, homemade egg & cheese muffins on whole wheat • Small medium-GI food: trail mix with fruit and candy, half a peanut butter sandwich • High-GI snacks: rice cakes, those delicious gummies from the coaches! • 1:4 protein to CHO recovery foods: chocolate milk, smoothie with dairy or dairy substitute base

29. Female Athlete Triad www.fasterskier.com

30. Important References for You • Health Canada Website: http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/index-eng.php#rvm • http://www.swimming.org/swimfit/what-to-eat-during-competitions/ • 7 signs the young swimmer isn’t eating enough: http://www.usaswimming.org/ViewNewsArticle.aspx?TabId=0&Alias=Rainbow&Lang=en&ItemId=6014&mid=11780

31. Thank you and have a great season!