Wow... I can't believe someone actually asked this question. It shows your bias.
Fat people don't stink be cause they are fat. However, anyone that doesn't wash properly will stink. That applies to skinny, regular sized, and fat people.
You might also take into consideration that certain foods can make people smell bad.
I also read a comment that said something like "a skinny guy in a 73F room will be cold, but a fat guy won't feel anything"... That is incorrect. Our bodies are not like those of other animals. Our fat isn't the same kind of insulation that a whale would have (for example). Our reaction to cold has more to do with our skin (and nerves)...not how skinny or fat we may be.
It's sad to see that this is obviously one of the last "acceptable" prejudices. Go out and make a fat friend today. You'll see that they are every bit as human as you are. Remember that everyone has their vices. EVERYONE. It's just that a fat person's may be food. It can be a drug of choice. It's crazy, you don't see alcoholics and coke heads being referred to in such hateful and negative tones... even though the addiction is similar.