How to help my obese mum and big brother?

When people emotionally eat its not really a problem that is easliy solved without some sort of counseling. With any addiction whether its drugs or food nobody will ever change unless they want to. You simply cant help someone who doesnt want to be helped. Maybe if your family saw how upset it made you then they would see the big picture. You need to make them understand its not about vanity its about their health. Don't stress yourself out trying to fix other people even if they are your family because it might just be a fruitless endeavor.