My understanding of Japanese culture is that it's vitally important to the identity especially of older people (who are being targeted) to maintain a connection with a company, and losing that connection is very humiliating. So by making it the company that "suffers" if a person doesn't make their weight conform, they are putting incredible social pressure on the person. I wouldn't be surprised if a lot of people did end up conforming even if they wind up with eating disorders. Also with the requirement that dependents also be thin, I think child abuse will result.

On the other hand it might be the final death throes of the company culture.