It is wrong to tease a fat person but at the same time a person needs to do something about it. If you are young and unable to reduce fat it is totally unacceptable. Only 1% of cases are related to medical condition which can be addressed only by doctor rest it is related to lifestyle. Parents should play a major role in controlling obesity because a fat kid will eventually become fat adult and it is really difficult after few years to reduce it though it is not impossible. Fat people may say that they are comfortable in their own body but the fact is they don't appear comfortable. They have problems in getting up, doing regular tasks. When they walk for few distance they start breathing heavily. So I personally feel fat people should be counseled rather than teased without affecting their confidence and personality.