The examine.com article discusses this - 0.8g is also the RDA in the US. The RDA is considered a bare minimum: This is considered to be the minimal amount of p

The examine.com article discusses this - 0.8g is also the RDA in the US. The RDA is considered a bare minimum: This is considered to be the minimal amount of protein a healthy adult must consume daily to prevent muscle wasting when total caloric intake is sufficient. According to recent studies, however, the RDA for protein may not be sufficient for healthy young men, older men, or older women. These studies point to 1.2 g/kg as the minimum intake before the body starts downregulating important non-essential processes, from immune function to muscle protein synthesis. Even a reanalysis of the data used to establish the RDA suggests the minimum intake should be at least 1.0 g/kg. They cite a study there where they shut subjects in a metabolic ward for 8 weeks and fed them a 40% caloric surplus. Those subjects eating near the RDA for protein lost muscle mass, i.e. it's not even sufficient to maintain lean weight when overeating.