A demand for the average American to eat more meat would have to explain, as a baseline, why our already positive trend in meat consumption isn't yielding positive outcomes. There are potential explanations (you could argue increased processing offsets the purported benefits, for example), but those are left unstated by the website.
[1]: https://www.agweb.com/opinion/drivers-u-s-capita-meat-consum...
[2]: https://ers.usda.gov/data-products/chart-gallery/chart-detai...
And even then this rule is not perfect because of individual genetics, metabolism rates, activity level, percentage of lean mass, etc.
Americans (US citizens) really do eat a lot. What the hell