Yep, age will. If the average age of an American woman has changed from, say, 30 years to 50 years (aging population, changing demographics etc.) then this coul

Yep, age will. If the average age of an American woman has changed from, say, 30 years to 50 years (aging population, changing demographics etc.) then this could contribute to weight differences because people tend to become more overweight as they age and get less active.