The premise that a ten year old car with 150K on the odometer might be in harder shape than a 15 year old car with 75K is not hard to accept, but I was somehow

The premise that a ten year old car with 150K on the odometer might be in harder shape than a 15 year old car with 75K is not hard to accept, but I was somehow very surprised to realize the analogous fact on bodies. Calories are essentially mileage for your digestive tract - top to bottom. Time-on-earth is easy to measure, but not obviously a good measure. EG, is time-on-earth a better metric than total calorie consumption? Doesn't feel straightforward to me.