Does the high-protein craze make sense from a nutritional perspective?
Broadly, yes, says Refaat Hegazi, PhD, medical director at nutritional products giant Abbott Nutrition, although the arms race between some companies competing to add more grams to their respective wares has gotten a little silly, he observes.
"It’s become almost a competition. I’ve got 17g of protein in my bar vs your 16g. Well there is no magic number."
The challenge is that how much we need varies considerably depending on age, weight, physical activity levels and other factors, so while many Americans are likely getting enough protein, others - particularly older people - should probably consume a bit more, he told FoodNavigator-USA.
So does he believe that the RDA for protein should be raised?
“The current RDA is 0.8g/kg/day, but some higher caliber studies and physicians are now asking for it to be raised to 1-1.2 g/kg/day, and I agree with them," he said. "And for patients admitted to hospital, that could be increased to 1.2-1.5g/kg/day or even higher.”
The extent to which you recover lost muscle mass after a period of acute inactivity is very dependent on your nutritional status
We all lose muscle mass as we age - around 1% each year from the age of 30 and twice that from the age of 70, while bouts of illness or injury prompting periods of physical inactivity (eg. a hospital stay) can exacerbate the problem, said Dr Hegazi, who says protein is critical to helping us recover or maintain muscle mass.
“We talk about primary sarcopenia, which is age-related loss of muscle mass, and secondary sarcopenia, which is illness-associated and can occur at any age.
“In general, many of us will have periods of illness and acute episodes of inactivity but the extent to which you recover lost muscle mass after these episodes is very dependent on your nutritional status, and protein is key to the recovery process.
“We also know that protein is important to the immune system,” he said, noting that when the body’s protein and energy needs are not met by the diet, muscle is broken down to provide amino acids, which can impair immune response, increase the risk of infection, slow down or stop healing, and even cause ulcers and other issues - which translates to longer hospital stays, and the increased likelihood of readmission.
Obese people are often malnourished and suffering from sarcopenia, he added.
In hospital settings, and in frail elderly populations, you often see malnutrition and sarcopenia in parallel, but the same is also true for obese people of all ages, he added.
“Around 60-70% of the US adult population is overweight or obese and around 30-50% of them might have some sort of sarcopenic obesity.
“People always jump on skeletal muscle mass [the amount of muscle connected to the skeleton to help us move around], but what I’m talking about is lean body mass [eg. a measure of the ratio of muscles, bones, etc to fat].
“But even the concept of sarcopenia is fairly new in the literature, so people are still debating the definitions.”
When should we eat protein?
So we know that ensuring we eat enough protein is important throughout our lives, and particularly during periods of enforced inactivity due to illness or injury.
But on a day-to-day basis, when should we get our protein? Does it matter if we eat our RDA for the entire day in one sitting (a big steak for dinner)? Or would we be better off spreading intakes throughout the day (eg. more at breakfast and lunch, less at dinner)?
For example, some studies suggest that to maximally stimulate skeletal muscle protein synthesis, the optimal amount is 25-30g of high-quality protein, around three times a day, and packing in more than 30g of protein in one sitting will not deliver any additional benefit.
Said Dr Hegazi: “It’s a very hot area of research at the moment and I’d say it’s not settled yet.”
There's no magic number
So how much protein should manufacturers pack into their products?
Much depends on whether you are selling a meal replacement or a snack, or if your target consumer is an elite athlete or bodybuilder or a couch potato, said Dr Hegazi.
“People look at the protein grams, but tend to forget that these products are consumed as part of an overall diet - and maybe you had eggs for breakfast and steak for dinner, so that needs to be factored in. You can’t look at each product [in isolation].”
