Don’t say “fat people.” You might insult someone. Rather, say “gravitationally challenged.”
Au contraire, my friend. Perhaps a “gravity overconsumer” is more appropriate, but that connotes overeating. I leave it to you to find a more sensitive term, but one that properly conveys the condition.
As an aside, we should all be looking to conserve gravity when possible. I know that the ASCG has been making strides to raise awareness of this.