Let's say you're an 18 year old male who runs every other day, logging 12 miles a week.
Now fast-forward to your late 40's.
Your eating habits are the same.
To maintain your high school weight, how many miles a week would you need to run?
Believe it or not, you'd have to multiply your weekly mileage 4 and 1/2 times, increasing it from 12 to 54 miles a week!
So, unless you take up weekly double marathons in middle-age, it's impossible simply to “outrun” middle-age spread.
That's because metabolism decreases with age.
At 50 you just don't burn as many calories as you did at 18.
Luckily, there are other factors in this equation.
Gradually eating less is one way to make up the difference, since metabolism slows by about 100 calories every ten years.
减少食量是一种弥补差额的方法 。因为新陈代谢的过程每隔十年就会降低100卡路里的消耗 。
That's equivalent to a tablespoon of butter.