The skinny one doesn't like breakfast. The other one usually eats a Leggo waffle plain, or a bowl of healthy cereal and milk.
No one has diabetes. My husband and I were really skinny kids, and we're both still fairly slim.
My tubby daughter almost died of a respiratory illness when she was a baby. She had very severe asthma for her first few years. She was on lots of steroids. She was sick and inactive during that time, and the medicine made her hungry. She still gets very winded, and I think the whole ashthma thing just slowed her metabolism. She weighs about 14 pounds more than her sister. She didn't have to put on that much weight each year, just 1 or 2 pounds a year would do it.
Ever hear of my favorite quote about economic forecasting?