Invisible fats

You might have heard this from somebody,that 'despite of cutting down all the fats and all the carbohydrate from their diet,they are still unable to get rid of this bulging tummy.You might have cut down the visible fats like ghee,butter,oils,deep fried foods from your diet,but do you know the fat majorly bad fats come in other forms also,which are known as 'invisible fats'. Can you tell me which invisible fats are you aware of ?