Putting aside the ridiculousness of the Big Agra's bedroom activity with the Government, what's your point? Corn is a type of grass after all. The same rules apply. If there's a problem with how corn in particular is raised and transported for cattle feed, that's really not central to whether raising cattle is bad for the climate in and of itself. Cattle can and are fed on grass all the time, even in cases when the cattle is grain-fed in the months before they are slaughtered.
> It's a fact that Americans eat more meat than they should
According to whom?
CDC, avg american men eats more than 100gm protein perday, CDC recommends 56.
Then read about blue region people who eats much less meat, in most Blue Zones diets people eat small amounts of pork, chicken, or lamb. https://extension.psu.edu/longevity-tips-from-the-blue-zones
How is this ridiculousness? The government heavily subsidizes corn, which makes it cheap to use to fatten up cows. If corn wasn't cheaply produced, it would be used less in beef production.
Government subsidies are why corn is in most products, and why it's being used for a percentage of fuel. The corn being produced is low in nutrients and high in sugar. The subsidies are not a positive thing for the economy or for our health.
Are you familiar with the recent developments in regenerative agriculture including livestock integration?
https://montanafreepress.org/2021/07/06/regenerative-agricul...
Sustainable livestock sounds great. But it won't scale far enough to meet even the current US demand, at least not if grown domestically. So maybe just subjugate a bunch of other countries, and ensure they do it sustainably! Can't be clear cutting rainforests we might need to breath or anything.
As we search out the threshold of unsustainable living maybe we could tap the breaks a bit first? Earth is a nearly closed system we must all share, and cows are a terribly inefficient way to produce protein and calories.
avg american men eats more than 100gm protein perday, CDC recommends 46-56. As you asked, now are you going to follow that? https://www.bluezones.com/2020/07/blue-zones-diet-food-secre...
https://peterattiamd.com/category/nutritional-biochemistry/p...
From what I could find sarcopenia's exact causes aren't fully understood yet.
Regardless of the correct quantities protein does not need to come from animal sources. And if we want to live with less suffering and environmental destruction we'll need to reduce reliance on animal protein.