I dunno. For some people, a healthy weight is "skinny". For others, it's "voluptuous". Trying too hard to attain an "unnatural" weight is unhealthy, no matter which "direction" you're trying in.
Ads like this one blanket all women as needing a certain amount of "tits", otherwise men wouldn't be interested in them. Without getting into how bad it is to have women care about their weight because of what some men will think instead of for their own health's sake - lesbians see ads also and should also care about their health despite not caring one bit how attractive they might be to men.