This is an interesting result, even though it seems to have arrived at the (edit: not!) same place sports nutritionists have been at for decades when it comes to the general population edit: 1g per kg. The things it says that I mostly hadn’t thought about or didn’t know:

1) older people are less efficient converting dietary protein into muscle, so they need 1.25g/kg

2) pregnant and lactating women obviously have higher needs, so they should eat up to 2g/kg!

3) children are doing a lot of growing, so they need 1.55g/kg

Americans get a lot of protein already in their diet (edit: for a sedentary lifestyle).

For the non-sedentary, I can say from experience (160lb, 5’10”, somewhat lean male) that eating 160g of protein spaced out in 4 meals (sports nutritionists also recommend spacing your protein intake out so that it’s consistently available) is actually pretty hard. You end up needing to eat a lot of chicken and eggs, unless you’re willing to go full-on body builder and start eating supplement shakes. Of course that’s while trying to keep a small calorie surplus — a lot of Americans are very overweight, and likely do eat more protein than they need because they eat more than they need of all the macronutrients.