If you’re trying to convince people that other people who write about food and health are catering to an elite and mostly-already-thin minority, but you are really concerned about poor and middle class fat people, maybe the best way to do that isn’t to refer to them as “the obese masses”, “the less affluent masses”, “the working-class obese”, “the obese public”, “the obese poor”, etc. That’s actually a good way to sound like you’re distancing yourself as much as possible from them.
David H. Freeman has a strong preference for calling people “the obese”, “the obese masses”, etc. rather than “obese people”, “obese Americans”, “obese adults”, etc. I counted 13 versions of the former and 5 versions of the latter.