You don't say..."heavy"

Don’t say: “Wow, you’ve lost a ton of weight!” 

Why: To a newly trim person, it might give the impression that they used to look unattractive. 

Instead say: “You look fantastic.” And leave it at that. If you’re curious about how they got so svelte, add, “What’s your secret?”


I agree.  Otherwise it seems like one of them there back-handed compliments.