It’s all just folklore. Until it happens to you.
Then it’s science.
Which makes better science: Anecdotes or folklore?
I’ve always associated protein powders with weightlifters and bodybuilders. The conventional lore being that weightlifting builds muscle mass and strength faster under a high-protein diet.
But I always assumed that was folklore. I figured that if you ate a reasonably balanced diet, that was enough. Loading up on any one particular nutrient — such as the amino acids in some “complete” protein — was at best unnecessary, and harmful if taken to excess.
Then the following happened to me:
My upper-body strength declined about 12%, over the course of 11 months, during which I lost about 55 pounds, or about 20% of my starting weight. (That estimate of strength loss is based on the settings on the weight machines at the gym, used a couple of times a week.)
This is a typical and expected side-effect of significant weight loss. Some of what you lose is muscle.
A month ago, I radically increased the protein in my diet. I went from accidentally eating far less protein than recommended, to eating 1 gram of protein per kilogram of body weight per day, or 100 grams for a (roughly) 100 kg person. This, with the aid of whey protein isolate powder.
Post #2005: 55 pounds and still a loser. Maybe boring is good.
In the month since I upped my protein intake:
- I’ve stopped losing weight, or nearly,
- I’ve regained all the upper-body strength I lost. Or nearly.
Hmm.
Maybe the muscle heads were right all along.
Turns out, the effect of dietary protein on muscle synthesis is not so large as to be immediately obvious. As a result, the scholarly literature on this subject — controlled trials of protein supplements for building muscle mass — shows mixed results.
That said, based on what Google Scholar tosses up, I’d say the consensus of opinion is that:
- For building muscle mass, weightlifting is far more important than protein supplementation.
- Adding protein to a weightlifting regimen does appear to increase gains in muscle mass and size.
- By contrast, protein alone (without weightlifting) may or may not do much for muscle mass, depending on whom you ask. For sure, the effect of protein supplements alone (not in conjunction with weightlifting) is small, at best, and may be non-existent among the elderly.
One graph, from one review (“meta-analysis”), pretty much sums up my view of what the scholarly literature says. More protein in the diet increases your lean body mass gain from weightlifting, modestly, up to a certain point. Beyond that point, additional protein results in no additional gains.
Source: Red title is mine, graph is from: https://bjsm.bmj.com/content/52/6/376, Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 2018;52:376– 84. doi: 10. 1136/ bjsports- 017- 097608.
To put that in perspective, their interpretation is that the weightlifters with the a high-protein diet (here, 1.6 grams protein per 100 kg body weight) gained about 3 additional pounds of fat-free body mass, relative to those who ate less than half that amount of protein. (That gain occurring over whatever the lengths of the underlying controlled trials were, with a minimum cutoff of six weeks of resistance training, in order to be included in the analysis.)
To understand the magnitude, you have to know how much muscle mass one can typically gain via weightlifting (absent use of drugs). A reasonable guess for that, for body builders, is on order of a pound a month. Call it 12 pounds a year, as a very respectable gain in muscle mass through weightlifting.
(I’ve never even come close to that amount. But I don’t do the sort of intensive weightlifting associated with increased muscle mass. I’m more of a “just trying to stay in shape” weightlifter.)
But the point is that an additional three pounds, of (presumed) muscle mass, from a long-term resistance training (weightlifting) program, just from adding a lot of protein to the diet? That’s material. That’s maybe 25% more gain in muscle mass, over the course of a year, from adding a high protein diet to a weightlifting regimen.
(By contrast, the increase in strength associated with adding protein to a weight-lifting program was somewhat smaller. The single-repetition maximum weight (“the-most-you-can-lift”), averaged across several muscles, was an estimated 9% higher for those with high levels of protein in the diet, compared to those with much lower levels.)
If I were a serious weightlifter or bodybuilder, my conclusion would be that protein supplements are well worth using.
But I’m neither. I’m just a fat guy on a diet. And yet I still conclude that protein supplements are well worth using.
Near as I can tell, a year’s worth of upper-body strength loss due to dieting was restored in a month, after switching from a protein-deficient diet to a high-protein diet, holding daily calories constant. All, in the context of twice-a-week, 15-minutes-per-session, HIT-style weightlifting at the gym.
Based on the research above, I’d likely do even better if I upped my protein intake again, to 160 grams a day (for my roughly 100 kg body weight). But for now, I think I’ll leave well enough alone, and continue to shoot for 1 gram protein/kg body weight/day.
Conclusion
My recent gains in strength are not a product of my imagination, or a faulty memory. For me, switching from a protein-deficient diet to a high-protein diet, along with lifting weights twice a week, resulted in the recovery of the modest (12%) loss of strength that occurred over the past 11 months of dieting.
Addendum: How did I end up protein-deficient?
Finally, I should probably explain why I wasn’t eating enough protein. Just in case anybody else has made the same boneheaded mistake.
You will frequently see guidelines stating that the average person needs at most four ounces of protein a day, and that four ounces of meat (“a piece the size of a deck of cards”) is a serving of protein.
I put those two together wrong, and concluded that, as a meat-eater, I didn’t have to worry about protein intake. If all it takes is a piece of meat the size of a deck of cards, I have that covered.
So I didn’t worry about it.
My confusion is that “meat” is not “protein”. Meat is mostly water. A typical four-ounce portion of meat contains about an ounce of protein. So the guidelines actually tell me that, in order to meet the guideline, I’d need to eat a pound of meat per day. (Or equivalent in protein-containing foods.) That would yield the four ounces (roughly, 100 grams) of protein specified in the dietary guideline.
I was not helped by the repetition of “four ounces” in the most-commonly-cited U.S. guideline.
But I now know exactly why that was stated that way. Turns out, you can’t process more than about an ounce of protein at a time, in terms of absorbing it for building tissues. Anything more than that, in a single meal, ends up being burned for the calories (or turned into fat and stored). To ensure that you meet your nutritional requirement for protein, not only must you eat about four ounces of protein a day, but that protein must be divided up into modest (one-ounce-or-so) portions, consumed throughout the day.
As a corollary, as crazy as it sounds, if you eat a one-pound steak every day, at a single meal, you risk ending up protein-deficient. Which now makes me wonder how one-meal-per-day eaters manage to avoid that.
I believe this is why the nutritional guidelines for protein always state two parts: Daily intake, and portion size. In my mind, I had simply confused the typical portion size (four ounces of meat) with the required daily intake (four ounces of protein).
The upshot is that you need four four-ounce pieces of meat (or equivalent), consumed at different times over the course of the day, to meet the commonly-cited requirement of four ounces of protein a day. Ensuring that much protein intake is kind of a challenge. For sure, I wasn’t coming close to eating a pound of meat a day (or equivalent in protein-containing foods).
