Sunday, August 4, 2019

Amount of protein in food

Cleveland Clinic is a prestigious hospital in the US particularly for its heart program. So their newsletters about health are of top quality as well. In the July 26, 2019 newsletter, Which Is the Best Protein Source?, we read

Grams of ANIMAL PROTEIN per 100 grams of:
36.71 veal
36.12 beef
32.08 lamb
28.86 pork
28.74 chicken
25.51 tuna
24.62 sardines
23.63 cheese
22.10 salmon
20.50 crickets
12.58 eggs

Grams of PLANT PROTEIN per 100 grams of:
22.21 peanut butter
20.96 almonds
16.89 oats
9.04 tofu
9.02 lentils
8.86 black beans

This article is adapted from Dr. Hyman's book "What the 
Heck Should I Eat?" (© 2018, Hyman Enterprises, LLC)
On p.37 of Mark Hyman's Food: What the Heck Should I Eat?, we find this list, citing as its source a webpage on wired.com, Know Your Meat—and Bugs. Introducing the Periodic Table of Protein. Unfortunately, the wired.com article does not give the source, which is unusual among articles on a health topic. But it doesn't take long to find that the ultimate source of it (as well as many others such as nutritionvalue.org) to be USDA (US Department of Agriculture), where you can search for very detailed nutrition data, probably too detailed for a non-specialist. Since the amount of protein in 100 grams of eggs is surprisingly low, only 12.58 grams according to wired.com or its downstream book and webpage, let's search for "egg" on the USDA website, and we get (grams per 100 grams of eggs)
Egg, white, dried: 81.10
Egg, whole, dried: 48.05
Egg, yolk, dried: 33.63
Egg, yolk, raw, fresh: 15.86
Egg, whole, cooked, fried: 13.61
Eggs, scrambled, frozen mixture: 13.10
Egg, whole, raw, fresh: 12.56
Egg, whole, cooked, poached: 12.51
Egg, white, raw, fresh: 10.90
Egg, whole, cooked, omelet: 10.57
Egg, whole, cooked, scrambled: 9.99
We can see that wired.com's Periodic Table of Protein or other similar sources quote the protein content of eggs (12.58g) from USDA as probably "Egg, whole, raw, fresh" or "Egg, whole, cooked, poached", not for instance, "Egg, white, dried", which would be too high, nor "Egg, whole, cooked, scrambled", too low. If we search for "veal", the most protein-rich food in the Periodic Table of Protein, on USDA, we get a hundred of entries. I have not determined which of them most closely matches 36.71 grams per 100 grams of veal.

In short, the simple protein nutrition list is a good reference, but it hides a lot of details about whether the food is raw or cooked, which part of the food is measured, and how it is cooked.

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