The facts about protein

If fat, protein, fibre and carbs were the X-Men of food, then protein would definitely be Wolverine. Think protein and you think bulk, lean muscle, fighting through pain and generally being so much butch-er than the rest (mmm, that reminds me, must remember to go to the butcher). Protein has been presented as the superhero food that will save us from skinniness, fend off flab and be the rescue remedy for mutant-like recovery after wicked workouts. Two questions arise, though:
1. Are all proteins created equal?
2. Is protein’s power unlimited?

Your body on protein

There’s a reason why Rocky chugged down eggs every morning . . .

Guzzling protein is vital for eight amino acids that your body cannot make itself. These are called “essential” amino acids and form the building blocks for muscle repair, building and maintenance. Unfortunately, the formula isn’t as simple as “eat protein, build muscle”. Eating protein beyond the recommended limit for your weight and activity can mean it simply becomes an expensive energy fuel or building block for fat. And it gets trickier . . .

“Recent research suggests that taking any more than 20-30 grams of protein at one time provides no further stimulation of muscle building,” says Dr Gary Slater, national performance nutrition coordinator for the Wallabies and senior lecturer of nutrition and dietetics at the University of the Sunshine Coast. “Typical intake patterns show that Australians get more than a half of their protein intake in their evening meal, with very little at other times of the day.” Do that and you’re robbing yourself of the potential benefits that protein can provide around the clock, because you get the same boost from a 120g (about 25-40g of protein) serve of beef as from a 300-350g piece of steak. “That’s why I try to include a small amount of high-quality protein in each snack and meal for all my athletes,” says Slater.

Protein needs will vary depending on your activity level and body weight. An average, not particularly active man, requires 0.8g of protein per kilogram of body weight, while a male power/strength athlete looking to bulk up may require as much as 2g per kilogram. When it comes to the outer limits, the Dietitians Association of Australia (DAA) recommends an absolute limit of 200g of protein a day, regardless of body weight and activity.

Too much protein cannot only be a waste, it can actually be downright dangerous. The process of breaking down protein into a useable form is more taxing on the body than dealing with carbs and fats. Too much protein can overload the liver’s capacity to convert the excess nitrogen (a by-product of assimilating protein) into urea. “This can cause damage to the kidneys,” warns dietitian Melanie McGrice, a spokesperson for the DAA. McGrice emphasises that although some proteins, such as whey protein isolate, may be more easily used by your body, “protein is still protein – you will still have that stress on the liver and kidneys”. Another reason not to overdo it? Protein can also carry in unwelcome gatecrashers like saturated fat, cancer-causing compounds and cholesterol.