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Vegan protein

I saw a comment on HackerNews (HN) today that claimed “[g]reen leafy vegetables also [have] a lot protein (Kale, Broccoli and Brussels).” In the context of the thread, I didn’t feel like it was really appropriate to point out that this is not really the case, but for my own curiosity I did look up some numbers and felt they were worth recording somewhere:

Food Protein
Kale (raw) 4.3
Broccoli 2.8
Brussels 3
Eggs 12.6
Chicken 24.7
Lentils 9.0

All of the protein values are from Wikipedia and in units of grams of protein per 100 grams of the food. Each food but the Brussels sprouts had a nice nutrition info panel with precise protein values, but the sprouts only said “3% protein.”

As you can see from the table, leafy greens are emphatically not a good source of protein. As a “bodybuilder”1, I’m probably a bit biased in that I (usually unsuccessfully to be honest) try to eat ~1 g of protein per pound of bodyweight, ideally in four ~50 g of protein meals per day. To achieve that goal for a single meal would require me to eat more than a kilogram of raw kale. The protein value for cooked kale is even lower at 1.9 g per 100 g. In contrast, I could eat 200 g of chicken or ~8 eggs (using 50 g as the size of a large egg according to Google). The HN poster also mentioned lentils and other legumes first, which are a more reasonable source of protein if you want to avoid animal proteins. However, another food I consider to have negligible protein, one slice of Wonder bread (28.5 g) contains 2.5 g of protein for a whopping 8.8 g of protein per 100 g. So you could eat 3.5 slices of white bread and get as much protein as 100 g of lentils.

Obviously there are other dietary considerations than just the amount of protein per gram of food, but it was a good excuse to find a few hard numbers to check the claim on HN.