Why do some people get fat while others don't?There is a strong genetic tendency to obesity. This is why fatness runs in families. Studies have been done of identical twins who were adopted out at birth and they always ended up being almost exactly the same weight even though eating differently and brought up in separate families. People are born with the tendency to be fat or lean. To try to fight against this and be something else is very difficult. If one parent is fat you have a 50% chance of being likewise. If both parents are fat then there is an 80% chance of being fat too.
Appetite and hunger are behind the problem of obesity. It has nothing at all to do with greed or gluttony as some people think. Fat people are just plain hungry even when they have eaten enough for their energy needs. Their stomachs just keep sending messages to the brain that they are hungry and hunger is one of the hardest feelings to ignore. The story about people having bottomless pits is pretty close to the truth and a lot of big people have never had the sensation of fullness – until they have surgery! The bottom line is that obese people eat much more than thin people because they have a much bigger appetite.