Many doctors think we need to get fitter and lose weight to be healthy.
But some people say the pressure to be too slim is as damaging as being overweight.
What do you reckon?
Unfortunately this topic is now closed but there are Comments pages on other subjects on the main Chat index.
I think your weight matters in some ways. If you weigh too much for you height then it means you are putting pressure on your heart and you could end up killing yourself. But I feel the most important thing is that you yourself are happy as a person.
Jodie, 13, Edinburgh
Why should people worry? You are what you are.
Hannah, 13, Ipswich
I think that it's alright to eat junk food once or twice a week, but I don't think you should eat it everyday.
Monordjo, 12, Leeds
I think if your unhappy about what you weigh don't diet but instead of eating junk eat fruit.
Beth, 10, Corby
Most children and lots of teenagers worry about their weight, but you are still growing so you should have fun. All you have to be is healthy.
Sarah, 14, Morecambe
Children and teenagers need to be taught that during your younger years dieting is not the answer to weight problems. A balanced diet and regular, healthy excercise is the way to go.
Eddie, 13, Bury
I think that obeseity is mostly caused by problems at home and not necessarily their lifestyle.
Naomi, 12, Stapleford
I don't think you need to weigh yourself - the most important thing is that you're fit and healthy.