At 20,I couldn't gain. Could polish off half a large pizza and follow it up with half a gallon of ice cream and not think twice.
After 40, forget it....thinking about half a gallon of ice cream causes me to gain! Enjoy the high metabolism while you have it.
Mini-rant: you don't turn fat into muscle. You gain muscle which replaces the fat in the areas it accumulated. Always hated that misguided phrasing.
When you stop working out, the muscle shrinks back down and the fat, which doesn't ever completely go away as a cellular entity, grows again.
Ok, I'm better now
