A new study suggests that adults should eat significantly more protein than national guidelines currently recommend, and that portions should be split evenly throughout the day.
The high-protein diet, outlined in a by the University of Mississippi and researchers at McMaster University, could help stave off muscle and strength loss in aging adults.
Researchers say the sweet spot is 30 grams to 45 grams of protein eaten one to two times per day -- but one researcher suggests a person could see benefits with three to five meals at that amount. (For scale, an average chicken breast contains about 25 to 30 grams of protein.)
鈥淭hat鈥檚 a pretty big dose of protein,鈥� said researcher and professor Stuart Phillips, who studies protein and physical activity at McMaster University.
鈥淏ut the more times people consume that dose, the greater their retention of muscle and the greater their strength that they measured using at least their legs, which is arguably the most important muscle that you want to preserve.鈥�
The findings are based off information from 1,081 Americans between the ages of 50 and 85 collected from 1999 and 2002 by the National Health and Nutrition Examination Survey, or NHANES.
Researchers zeroed in on the relationships between participants鈥� leg strength and how much protein they consumed. From that, they found a positive relationship between protein consumed in multiple meals and overall leg lean mass and strength.
'A big jump' from the norm
The conclusion may sound obvious -- more protein, more strength -- but the amount of protein researchers recommend far exceeds today鈥檚 national guidelines.
For example, a man weighing 80 kilograms (176 lbs.) requires 64 grams of protein under the recommended dietary allowance (RDA), a common benchmark in the U.S. and Canada. But Phillips suggests that such a person would benefit by boosting that protein intake to between 90 grams and 135 grams across three meals.
That鈥檚 more than double the national standard, but Phillips insists the suggestion isn鈥檛 鈥渞adical.鈥�
鈥淚 think that it might shock some people and it鈥檚 definitely a big jump from the RDA, but I think that 鈥� there鈥檚 enough science now that鈥檚 beginning to emerge that challenges the adequacy of the RDA for older persons,鈥� he said.
The study itself did not consider the type of protein consumed, but Phillips says the diet could be followed with either plant- or animal-sourced protein.
And the message isn鈥檛 simply that more protein is better, Phillips insists.
鈥淚t鈥檚 that you should probably distribute it in a balanced fashion. So take some of the protein that you鈥檙e eating at dinner and maybe consume a smaller portion there and consume more protein at breakfast and lunch time meals.鈥�
The study did not specify the timing between meals, but Phillips suggested at least three hours.
He also point outs that the research is a step forward, but it鈥檚 not the final word on protein.
鈥淭his is a hypothesis generator rather than bona fide as fact,鈥� he said.
Works for 鈥榓nybody鈥�
Phillips says the diet could work for 鈥渏ust about anybody,鈥� and it becomes increasingly important for people to eat more protein in their forties and fifties when they may begin to lose muscle mass.
But people who don鈥檛 exercise often may experience muscle loss sooner in life and require a high-protein diet earlier.
鈥淚f you assume a fairly sedentary lifestyle and you have a fairly sedentary workplace, then you鈥檙e going to lose muscle mass at an earlier and probably more rapid rate than somebody else,鈥� Phillips said.
Phillips compared muscle loss to bone mass loss in women going through menopause. Rather than fight the problem when it strikes, Phillips says it鈥檚 better to prepare with the appropriate diet.
鈥淚t鈥檚 definitely preventative. There鈥檚 no question,鈥� he said.
Too much protein?
There are a couple 鈥渕yths鈥� associated with high-protein diets, Phillips says, including an increased likelihood of kidney failure or that it causes bones to 鈥渄issolve鈥� by leeching calcium.
鈥淣either of those have any scientific basis,鈥� says Phillips, whose research pertains particularly to protein. 鈥淚 don鈥檛 see the smoking gun.鈥�
But eating more protein could tip the scale on consumption of other nutrients, like carbohydrates and fiber, so Phillips says it鈥檚 important to keep a balanced diet and not 鈥渂lindly鈥� eat more protein.
Maintaining an active lifestyle is just as important as eating a balanced, protein-rich diet, Phillips says.
鈥淚 won鈥檛 say that one trumps the other 鈥� but I think you can cure a lot of evil from a disease and poor diet standpoint from a lot of good exercise,鈥� he said.
The study will appear in the international journal Clinical Nutrition in the next few weeks.
