Weight Lost and Quitting Smoking

Something that I found mind-boggling: when someone wants to quit smoking, their friends and family are always supportive, including the other smokers. People respect others choices to quit smoking. Even if they can't help but to smoke in front of them, they don't dangle a cigarette in front of them to tempt them back into smoking. It's a kind of decency. What I don't understand is why can't this kind of decency extend to a person trying to lose weight?

Losing weight is an universal problem. Men, women, fat, thin, we ALL understand how important (and impossible) it is to lose weight. YET people NEVER think it's a bad thing to offer sweets to a person who's on their path to weight losing. There is nothing wrong to offer someone else candies, sweets, cakes, doughnuts. Never mind that the person is borderline morbidly obese. "Oh, here's a box of doughnuts for your trouble," or "here's a large cup of 600 calories Starbucks drink." Never mind if they are already (or well on their way to) diabetes. The most ironic part is: EVERYBODY can tell you that doughnuts are BAD for you, but it's acceptable to offer to a friend. What kind of a world is this?