7. "You're no fun anymore."

Variation: "Nobody likes to eat with you now." "Your diet is ruining my appetite."

Why it's unhelpful: Criticism of any kind undermines progress. And when commentary on diet becomes a commentary on personality, too, it's just plain rude.

Better: Remember that the comments we make to others about their weight-loss efforts tend to highlight our own insecurities, says Caring.com's Reardon. Ask yourself why you think the person is "no fun." Is it because you feel guilty about your own food choices or lack of willpower? Because food was central to your friendship, and your friend or loved one has moved past that?