Kids and Protein Shakes
At what age is it appropriate for my child to have a protein shake?
Nutrition plays an important role in optimizing training outcomes. Exercising stresses the body, and this stress serves as an important stimulus, telling the body to adapt by becoming faster, stronger, more powerful and fatigue resistant. For instance, the first time you lift weights will likely leave you feeling sore afterward. The more you do it, though, you notice that first weight you lifted starts to feel lighter. Your body adapts to the training stimulus by becoming stronger, allowing you to perform the same exercise, using the same weight, with greater ease. Pretty soon, it becomes too easy, and you’re ready to move on to heavier weights. How much benefit we gain from our training sessions can be impacted by how we fuel our bodies before, during and after exercise.
Post-workout nutrition plays a crucial role in helping the body repair muscle damage from exercise. It also stimulates muscle protein synthesis, or the growth of new tissues, enzymes and other cellular structures. Dietary protein provides the building blocks for this new tissue growth in the form of amino acids, and thus becomes an especially important nutrient during the post-workout recovery period. For this reason, protein shakes are a popular option for delivering protein to the body after a hard workout. Many parents wonder, however, if they are necessary or appropriate for children, at what age.
Rather than establishing an age limit for protein shakes, it’s more important to understand how much protein an athlete needs to recover properly and whether that need is great enough to warrant the use of protein supplements. Current scientific literature recommends 0.3-0.4 g of protein per kilogram of body weight, along with 0.8-1.2 g of carbohydrate per kilogram of body weight, within two hours after exercise to optimally stimulate muscle protein synthesis. Other researchers encourage consuming this post-workout snack as soon as 15-30 minutes post-workout to take full advantage of this recovery window. While the protein provides the building blocks to build and repair muscle tissue, carbohydrates help by stimulating the hormone insulin, which facilitates the uptake of amino acids into the muscle cell.
To find out how much your child needs, use the following formulas to determine the athlete’s weight in kilograms and the recommended amounts of protein and carbohydrate:
Weight (lbs) / 2.2 = Weight (kg)
Weight (kg) * 0.3 to 0.4 = Protein (g)
Weight (kg) * 0.8 to 1.2 = Carbohydrate (g)
For example, child who weighs 80 pounds would be about 36 kg. Based on 0.3-0.4 g of protein/kg and 0.8-1.2 g of carbohydrate/kg, this would equal approximately 10-15 g of protein plus 30-45 g of carbohydrate. Considering that most protein shakes contain between 20-30 g of protein per serving, a child this size would not need such a high amount of protein and could meet his or her recovery needs with a whole-food option such as a container of Greek yogurt (12-15 g protein) or 10-12 oz of chocolate milk (10-12 g protein).
Older kids, such as those in middle or high school, may need more protein depending on their body size, and a protein shake containing 15-25 g of whey protein is just one convenient option. Keep in mind that there are plenty of whole-food options that would accomplish the same goal. Here are some examples of snacks containing approximately 15-25 g of protein and 30-60 g carbohydrate that would be ideal for post-workout recovery:
1 cup of Greek yogurt + 1/2 c granola
8-16 oz chocolate milk (dairy or soy milk)
Turkey sandwich on 2 slices whole wheat bread (or 6-inch turkey sub)
2 scrambled eggs with whole wheat toast and peanut butter
Grilled chicken or salmon, sweet potato, and vegetables
Fruit smoothie made with 1 cup of Greek yogurt
1 cup of edamame or tofu with vegetables and brown rice
TIPS FOR CHOOSING A PROTEIN POWDER:
Look for products that have been third-party verified by the National Sport Foundation (NSF), which shows the product has been tested and found to meet the label specifications, and is free of substances that are banned by the NCAA and IOC. Look for the NSF symbol on the packaging or download the NSF mobile app for a list of products that are NSF Certified for Sport.
Whey protein appears to be most effective due to its rapid digestion and absorption, as well as its high leucine content. Leucine is one of the amino acids present in higher concentrations in milk-based products and has been demonstrated in laboratory studies to enhance muscle protein synthetic pathways to a greater extent than products with lower leucine content.
For lactose-intolerant or vegan athletes, plant-based protein supplements that contain a combination of proteins derived from plant-based sources, such as pea and brown rice, are available as an alternative to whey protein.
Check for carbohydrate. Many products are low- or no-carb, so if this is the case, make sure to add a source of carbohydrate such as fruit to the post-workout recovery snack.
Dose appropriately according to 0.3-0.4 g/kg of body weight. More is not always better, and research indicates that there is no added benefit to consuming larger doses of protein in the post-workout recovery period. Use the following chart to quickly and easily determine an appropriate amount of protein and carbohydrates for recovery:
When in doubt, consult a board-certified sports dietitian for specific guidance.
Optimize your post-workout recovery with the 3 R’s:
RE-HYDRATE with 24 oz of water for every pound of water weight lost during training.
RE-FUEL with carbohydrates: 0.8-1.2g of carb per kilogram of body weight.
RE-BUILD with protein: 0.3-0.4g of protein per kilogram of body weight.
FOOD FIRST, SUPPLEMENT WISELY! A protein supplement is meant to do just that – to supplement the diet when the body’s nutritional needs cannot adequately be met through whole foods. It should not take the place of good nutrition, and you can’t out-supplement a poor diet.
1. Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine. (2016). Position of the American Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics, 116(3), 501-528. DOI: 10.1016/j.and.2015.12.006.
2. Campbell, B., Kreider, R. B., Ziegenfuss, T., La Bounty, P., Roberts, M., Burke, D.,…Landis, H. L. (2007). International society of sports nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition, 4(8). DOI: 10.1186/1550-2783-4-8.
3. Dunford, M. & Doyle, J. A. (2012). Nutrition for sport and exercise (3rd Ed). Stamford, CT: Cengage Learning.
4. Jeukendrup, A. & Gleeson, M. (2010). Sports nutrition: An introduction to energy production and performance. Champaign, IL: Human Kinetics.
5. Kerksick, C., Harvey, T., Stout, J., Campbell, B., Wilborn, C., Kreider, R.,…Antonio, J. (2008). International Society of Sports Nutrition position stand: Nutrient timing. J International Society of Sports Nutrition, 5(17). DOI: 10.1186/1550-2783-5-17.
Noel Williams, MS, RD, CSSD, LD is a Performance Dietitian at Children’s HealthSM Andrews Institute Sports Performance Powered By EXOS. She earned both her BS in Nutrition and Dietetics and her MS in Exercise Physiology and Sports Nutrition from Montana State University. She conducted her Master’s research on cardiovascular and metabolic demands of Rocky Mountain Elk Hunting. Noel is a Board Certified Specialist in Sports Dietetics, and has taught workshops on developing positive eating behaviors in children in partnership with Montana Team Nutrition. She is also a part of the following professional organizations:
•Academy of Nutrition and Dietetics
•Texas Academy of Nutrition and Dietetics
•Sports, Cardiovascular, and Wellness Nutrition Dietetic Practice Group (SCAN)
•American College of Sports Medicine