How much protein is too much? A simple question, yet not one that is easy to answer.
Some exercise researchers say more protein is better. It’s filling, beneficial for appetite suppression and weight loss and also helps prevent loss of muscle mass and strength as people age. Animal sources of protein are also loaded with essential nutrients and amino acids, like iron and folate.
For all these reasons, some researchers say we should consume a lot more protein than they probably do; up to 0.75 grams of protein per pound of our body weight every day, says Dr. Stuart Phillips, a professor at Canada’s McMaster University. For a 150-pound person, that works out to roughly the amount you’d find in a chicken breast or similar size cut of meat, a cup of beans, six ounces of Greek yogurt and eight ounces of milk.
However, others take a contrary view. Research by Dr. Valter Longo, a professor of biological science at the University of Southern California, shows cancer rates increase nearly 400% among Americans who get 20% or more of their daily calories from protein; compared to those who restrict their protein intake to 10% of their daily calories. His data shows a risk of mortality of 75% among the heavy protein eaters.
There are a number of important factors here that people who eat lots of protein are probably getting protein from unhealthy sources. But Dr Longo says, even if we cut out fatty, processed meats such as fast food burgers, breakfast sandwiches etc. there is still evidence to suggest protein consumption fuels disease and early death.
Based on his longevity research, he recommends people get no more than .37 grams of protein per pound of bodyweight, roughly half the amount Dr Phillips recommends. For a 150-pound person, that works out to about 50 grams of protein daily.
For people over 65, muscle wasting and loss of strength become important concerns, so much so that eating more protein lowers your risk for both death and disease, Dr Longo says. Once you hit 65, it’s fine to consume a bit more protein if you notice you’re starting to drop weight, lose strength or shed muscle mass.
All of this no doubt seems confusing and convoluted. But you can probably forget about counting protein grams if you do just one thing and that is to adopt a Mediterranean-style diet. Fish contains about half the protein found in chicken or red meat, and the other staples of the Mediterranean diet, olive oil, vegetables, whole grains and legumes, have low or modest amounts of it.
That may be one reason why Mediterranean diets have repeatedly been linked to a longer life and lower rates of disease and it’s just one more reason to adopt the diet convincingly supported by research again and again.
As highlighted in my blog today, the key is moderation.