While it will be of little comfort to anyone who has been bullied over their weight, it is suggested that thinner humans have an inbuilt dislike of fat people because of ancient fears that they may be diseased.
Researchers found that the mere sight of someone who is overweight can trigger feelings of disgust and nausea similar to encountering rotten food.
The research, reported in the journal Evolution and Human Behaviour, claims that our brains have evolved to react to outward signs of disease, such as rashes and wounds, because bacteria and viruses are invisible.
Unfortunately, these signals also include excessive body fat.
http://www.dailymail.co.uk/news/article-471711/Scientists-discover-people-dislike-fat-people.html#ixzz4lmrPX7E9 
