Everybody needs to eat more protein. The RDA is around 10% of your calories. One recent study confirmed that this is too low and the test subjects lost muscle mass on it. That is to say, people who were made to follow the national dietary guidelines lost muscle. These dietary guidelines are probably one reason that the elderly in our country often have partial wasting. (The other is that they are very sedentary.) People who got 20% to 25% of their calories from protein gained muscle mass, even without exercise. Though to be fair, many of them probably had been getting just the RDA and were having a rebound effect from having careful management of their diet to ensure they finally had enough of it in their diet. Hunter-gatherers eat a lot more protein than we do, but much of it is in the form of things like worms, termite grubs and other insects (the only insect product we eat in quantity is honey).
Getting usable protein
There are essential and inessential proteins. Inessential proteins are those made by your body and if eaten, are usually burned for calories. Grains mostly have these. This is a problem with nutritional information in that “protein” refers to all types of protein. Noodles contain 10% protein in the form of mostly gluten (when uncooked) but living only on noodles will make you protein deficient, even though exactly 10% of your diet is protein. Proving yet again that man cannot live by bread alone. Almost the only reason I can see for protein supplements is to offset the misleading labeling of most foodstuffs. (Yes I sometimes use them myself, especially when travelling or if my diet is out of whack due to being busy, but I do try hard to get all of my protein from real sources like meat, cheese, and eggs.) You do have to be careful when buying, since cheaper brands can up the protein with cheap filler, like wheat gluten, which gives impressive numbers but empty calories.
Essential proteins come from animal sources mostly. It is true that soy and some other grains have them, but since soy contains isoflavones which are converted to estrogens in the gut, women can get good benefit from them, but guys can get their hormones seriously deranged and there have been more than a few cases of vegan powerlifters who ended up eating tons of soy sprouting breasts and even some vegan men who started lactating. Most plants have natural defenses against being eaten and in the case of soy, isoflavones chemically neuter any male that feeds heavily upon them, so it is, in effect, a type of pest control. No generation of hungry little bugs will result.
Also soybeans (like lima beans) contain a substance called a trypsin inhibitor which prevents digesting all protein. This can only be broken down by heating, so I do not advise vegetarians to eat too many raw soy products. Need I say that the raw foods movement also gives bum advice? Lima beans contain unacceptable levels of cyanide when uncooked, for instance. In the case of raw foods, the moralizing is about the evils of industrialized agriculture. Suffice to say that the two greatest advances in human history were the switch to an omnivorous diet, which involved growing more brain tissue to hunt (have to be clever enough to predict what prey will do — why do you think cats are so curious?) and later the cooking of food, which allows us to extract enough nutritional value to feed said brain.
|Whole wheat bread||21%|
A useful metric is the NPU or Net Protein Utilization, which is a somewhat older score. Compare this with the more modern PDCAAS or Protein Digestibility Corrected Amino Acid Score. Both measure how much protein (as a percent of what is consumed) is actually used, based on measuring what is eaten against what is excreted. PDCAAS has different corrective factors than the NPU. (To be more blunt, PDCAAS has built in skew for agricultural incentives that have nothing to do with food. Soy gets an elevated score, for instance, based on promoting it as a foodstuff in the Third World rather than simple scientific evidence.) I find from experience that the NPU seems to reflect what works for me. YMMV though, since I might just be a statistical outlier. In this, vegetable sources tend not to fair too well. Again, because their specific proportions are not optimal for animal growth. The best external source is egg whites. Beef gets goodly score at 68 and soy gets a passable one at 48. Wheat and other whole grains get dismal scores of about 20.
This refers, I hasten to add, to the ratio of protein consumed to excreted. Brown rice has a good protein NPU but the quantity is low, at only 2.5% by cooked weight. So to get 100% of the RDA of protein on a 2000 calorie diet, taking the NPU into account requires you eat nearly 5 kg or 11 lbs of cooked brown rice per day. This is about 6,000 calories.
One other gripe about vegetable sources of protein. There are some newer ones, such as hemp and rice protein powders which have passable profiles. These are marketed as vegan, healthful, Earth friendly and natural. The amount of protein naturally ocurring in, say, rice, is low, so huge quantities of it have to be processed by washing off all the starch and collecting the remains. Anyone remember corn oil and how evil it is? Corn has only a tiny amount of oil in it (there’s a reason you butter it on the cob) and the natural foods argument against it was precisely that so much processing was required to get it, that it must not actually occur in a human diet. Fair enough. As by products of large-scale industrial food processing, this makes, sense. I take exception to being told many of these newer foodstuffs are either natural, more healthful or in some intangible way better. (For whom? The carbon foot print for making rice protein is simply huge compared to beef.) This does fit in with my experiences of vegans who are very long on preaching their better-than-you-ness while giving awful dietary advice and, it being a mostly upper middle class phenomenon, require a gigantic industrial base to produce it at the requisite quality. Then it has to be sold in posh little boutiques. These are by and large luxury items being marketed not on their intrinsic value as much on their ethical purity. If you buy into that, fine. Please to not tell me it is nutritional advice.