What credibility or scientific backing does 1g protein per 1lb of body weight have for its applications?

Question

Say you're of an average weight, not really fat, just skinny and want to put on pounds. People who want to add muscle but are not yet serious bodybuilders(if that's even their goal)are advised to consume 1 gram per lb of body weight to bulk. Bodybuilders are typically advised 1.5-2g/lb.

Now, even overweight people who are trying to lose fat weight are also told the same thing:1g/lb.

But one thing that always intrigues me when I see it(StrongLifts report comes to mind)is when someone claims that consuming excess protein isn't necessary.

One common argument that comes from that stance is that people way back in the olden days(think 1100-1800s) didn't need 1g/lb of protein to put on mass or to get cut. Hell, who even knows if they knew anything about cutting or bulking. Most men were just naturally lean, probably from daily physical labor that was just apart of living back then, and probably due to a lot of natural and unprocessed foods(well, this could still be another question of credibility but it's not the purpose of this post).

And then the assertion is followed up with some drivel about how the ratios are just propagated through things like marketing and broscience to increase the volume of sales of whey and other protein powders. The skeptic in me wants to be like "Yeah, that does make sense actually, these industries are huge cash cows, etc., etc.", but, I'd rather have an informed opinion.

So I'm wondering, if you want to add on lean weight or lose fat weight is there really any credible research or studies showing that consuming 1gb of protein per pound of body weight has any significant impact on trying to reach your goals?

And how much protein should an individual who is resistance training for fat loss consume per lb of body weight?

Answer 1

Well, you've kind of asked the million dollar question, as there haven't been any really definitive studies (That I am aware of) specifying exactly how much protein is needed for training, and especially when related to fat loss, as that can be highly individual specific.

This study examined nitrogen balance and lean body mass preservation related to protein intake, and found that when not training, bodybuilders needed little more than sedentary to maintain mass, while protein needs did increase during training, and endurance athletes needed more than bodybuilders, being 1.12 x sedentary control levels for bodybuilders, and 1.67 x sedentary control for endurance training. (They do not note sedentary levels in the summary).

An article in JAMA talks about the protein needs from the RDA perspective, which does not include training needs, concluded .8g per kilogram for adults older than 18. This somewhat fails, however, in that it doesn't consider females vs. males, and elderly and/or middle aged.

They do note, however, that there is no upper limit for protein intake (i.e. more won't necessarily hurt you), so if you take their .8g/kg rate, and multiply that by the 1.12, you come out just shy of .9g/kg. So 1g/kg should easily put you in the ballpark, and you could consume a little more without repercussion.

This article (Sorry, but it is behind a paywall) discusses metabolic needs of athletes, and suggests that a diet that is at 30-35% of calories from protein (compared to the general recommendation of 15%) should be sufficient. (It also suggests greater fat loss and a couple of other effects, but again, many of these are not yet proven.)

tl;dr

There is some evidence to suggest that 1.0g/kg is a good target, and more than that probably won't hurt in any way, with addition of endurance exercise or very intense activity increasing the need for protein.