DS1 was 8lb10 and 61cms at birth. He was a very chubby toddler but lost it all around 2. He then chunked up again at about 9 years old. He is now 11 years old, 6 feet tall and 60kgs (135lbs), so perfectly proportioned.
DS2 was 8lb5 and 59cms at birth. He was a MASSIVELY fat baby and toddler. He was very solid but not fat until he turned 7 when he started getting taller and slimmer. He's now 8 and is extremely tall, solid but not an ounce of fat on him.
DD was 5lb11 at birth she was the fattest baby you have ever seen. She didn't overeat and although we were worried had nothing wrong with her. She is now 5 and still slightly chubby but not overly so. I expect her to go the way of her brothers and lose all that baby fat by the time she's 7.
My kids do naturally hold their weight, so we do have to be careful with what they eat. They have to do lots of physical exercise to keep them at good weight/height ratio and not overweight. I know I am the odd man out on this thread, but I do see some correlation between my much heavier than average babies and their weight as they have gotten older.
Given we are not a family who eats fast food, my kids don't drink soda or juice (just water or low fat milk), it's obviously just in the genes (I was a humungous baby and toddler but slimmed out and stayed that way since I was 8/9).