Skip to main content

The question:

My preteen son – a hockey player – wants to bulk up and has asked me to put protein powder in his smoothies. Is this safe in a young physique? What's the difference between vegetable, whey and soy protein? What about his older brother, who is well past puberty but not yet an adult?

The answer:

Protein supplements are popular with many young athletes who want to become bigger, stronger and faster. Before you start adding protein powder to your son's smoothies, determine if he really needs it. Consuming protein above and beyond his daily needs won't build more muscle and, in some cases, can be harmful.

Increasing muscle size to gain power and speed on the ice requires extra protein and a training program. But there's one caveat: Neither will produce larger muscles if your son hasn't gone through puberty yet. Light resistance training can, however, improve his muscle tone and strength.

Your son does need extra protein to fuel his workouts because his body is still growing and uses more protein in general. According to the U.S.-based Institute of Medicine, 9- to 13-year-old boys require 0.95 grams of protein per kilogram of body weight per day. Anaerobic sports that require short bursts of intense energy, such as hockey, may also add another layer to your son's protein needs.

Protein requirements have not been specifically evaluated for young athletes, but some experts suggest active boys need 1 to 1.5 grams of protein per kilogram of body weight per day (0.45 to 0.68 grams per pound of body weight per day). For a boy who weighs 100 pounds (45 kg), that translates into 45 to 68 grams of protein.

That may sound like a lot but it's very doable to get it all from food. Two egg whites, 3 ounces of tuna, 3 ounces of chicken and 2 cups of milk, for example, provide a total of 65 grams of protein. Swap one cup of milk for ¾ cup of Greek yogurt to get 75 grams of protein.

Even so, there may be a place for protein powder in your son's diet. Busy kids who don't always have time to sit down to a balanced meal may be shy of hitting their daily protein target. Young vegetarians as well as kids who fill up on carbs might also be light on protein. In these cases, the judicious use of protein powder can fill the gap.

For older teens, taking a protein supplement can help build muscle, particularly if it's consumed shortly after a workout and when combined with a source of carbohydrate such as milk, almond milk or fruit. The carbohydrate replaces lost energy and triggers the release of insulin, a hormone that allows muscle cells to take up nutrients.

If you decide a protein supplement deserves a place in your young hockey player's diet, choose a protein powder rather than a ready-to-drink protein shake. Many premixed protein drinks contain fillers and added sugars that kids don't need. And some may contain ingredients that could be unsafe for teens.

A homemade smoothie made with protein powder, fruit and milk/yogurt or a non-dairy beverage such as soy or almond milk delivers protein along with plenty of calcium, potassium and antioxidants.

Don't overdo it, though. Excess protein can be hard on the kidneys and liver and cause unwanted weight gain, calcium loss and dehydration. Athletes who are training hard shouldn't consume more than 2 to 2.5 g of protein per kg of body weight per day.

My advice for your 12 year-old: Stick to whole foods for protein and, if needed, bridge the gap with a protein powder.


Protein powders typically deliver 15 to 30 grams per 30 gram serving, depending on type. Look for one without artificial sweeteners and flavours.

Whey protein:

Removed from milk during the cheese-making process, whey protein is a complete protein, meaning it contains all nine essential amino acids, protein building blocks the body can't make on its own. It has little fat, no lactose and is quickly digested. Whey protein may cause bloating and stomach upset in some people.

Soy protein:

Made from defatted soy flour, soy protein powder is an alternative for vegetarians. Products typically contain soy protein isolate, a highly purified form of soy that has the carbohydrate removed, leaving 90-per-cent protein. Like whey, soy protein contains all essential amino acids.

Brown-rice protein:

It contains B vitamins, iron and a little calcium and while it's not a complete protein, as long as you eat a variety of protein foods during the day, you'll get all the amino acids you need. It's sold on its own or blended with hemp and pea protein.

Hemp protein:

This protein contains all essential amino acids and it's a good source of fibre, B vitamins, iron and omega-3 and omega-6 fatty acids.

Leslie Beck, a registered dietitian, is based at the Medisys clinic in Toronto. She can be seen every Thursday at noon on CTV News Channel's Direct;

Report an error

Editorial code of conduct