Ira...being healthy is what counts....not the shape of your body. There are many skinny people in this world that have numerous health issues and are not in shape at all.
Focus on staying in shape (internally) and dont worry much about weight and body shape.
AE, i am nothing like my ammi. Ppl tell me i dont look like her daughter at all. I take after my khala who is tall and broad while my ammi is short and petite. Guess who DOES take after her? My skinny sister :(