Comment by zmmmmm

But what if I like pizza?

The thing is, the 300 calories from rowing shouldn't be compared to the absolute calorific requirement (say 2500 calories) but the surplus. So Maybe I'm overweight because I need 2500 and I eat 3000. Thats 500 too much, but take out 300 and that's 60% of what I need to at least reach equilibrium. It makes a huge difference to how much I need to sacrifice out of my diet.