This is an interesting issue in the Paleo/Low Carb world with a lot of opinions. There is also a lot of BroScience mostly from (Austrian voice on) HUGE (Austrian voice off) men who believe that consuming lots of protein and lifting only odd amounts of weight on even numbered days is the reason they are (Austrian voice on) SO HUGE (Austrian voice off.)
So here it goes.
WebMD says we dudes need about 56 gm/day, women slightly less. This is conventional wisdom of 0.8 gm/kg body weight/day. I’m about 70 kg so that does indeed come out to 56 gm.
Paul Jaminet says we need to eat about 8-16 oz of animal protein/day, and gives a formula of 7 gm protein/oz; so 56-120 or so gm/day. (The Perfect Health Diet, an interesting read!)
Atkins says to eat a portion of protein about the size of the palm of your hand each meal. My palm measures 9x8x2.5 cm which is about 180 cc or pretty close to 180 gm. That is about 6 oz/serving x 3 = 18 oz, a touch more than Jaminet recommends. That calculates out using the 7 gm/oz rule as 126 gm. Google says 139 gm in 18 oz of steak.
There are some people who recommend more like 1.2-1.6 gm/kg/day. For me that’s 84-112 gm/day.
On the low end, Nora Gedgaudas recommends a lower dose of around 5 oz of protein foods/day based on an interesting hypothesis about longevity being better with lower amounts of protein, especially the amino acid methionine.
If you are going ketogenic/nutritional ketosis, Jimmy Moore has found with his large frame body, over six feet and well into the 200’s of pounds, that if he consumes more than about 80 gm/day of protein his body kicks him out of ketosis. Atkins and low carb diets should NOT be “high protein” but “moderate protein.” Eades of Protein Power also warns against too much protein on his blog, to prevent, again, being kicked out of ketosis.
So why would protein kick a person out of ketosis? Isn’t ketosis caused by burning fat instead of carbs? Well, yes, BUT…
Our bodies can store fat (obviously; look at my abdomen two years ago.) Our bodies can store carbs (some in glycogen in the muscles and liver, and the rest as…FAT.) See my previous post about carbs, low carb, ultra low, etc. What we CAN’T store is protein. Excess protein goes to the liver where it is metabolized to glucose and various nitrogen products. Making new glucose out of protein is called gluconeogenesis (gluco, sugar; neo, new; genesis, formation.) That glucose is chemically identical to the nasty glucose from refined flour or sugar and does the same thing to our pancreas, stimulates insulin production. If your goal is to lower insulin and burn more fat, too much protein will stall you out.
Some people think that protein intake is a stronger appetite signal than calories and indeed Volek and Phinney somewhere in their writings reference a study where they tried to put athletes on “low carb” by feeding them lean steak in large amounts. (You can’t feed them FAT for pete’s sake, right?) The athletes said after just a couple of days that they felt, well, bad. We don’t like to eat too much protein.
I personally am trying to listen to the old body on this one. I seem to like protein after my Trufit Body By Science style high intensity weightlifting program (last night, a new personal record on the leg press, 265 lbs with a time under load of 2:17.) Other times a salad is all I need.
One of these days I’ll complete the trifecta with a few thoughts about…the evil…killer…fat!