I don't think I ever said it doesn't matter.
If you exercise a great deal, if you're a marathon runner or training for a triathlon, it is possible to outrun your fork. However, on a population basis, that's not the case. A number of studies have looked at this.
For example, if you look at the number of calories you drink in 20 ounces of Coke, an adolescent would have to jog for 50 minutes to wear that off. The balance just isn't there. Is it possible? It's certainly possible, but on a population basis, is it likely? No. It's extremely improbable.
We're looking at what's going to have the biggest influence on a population. When you look at these dietary or lifestyle interventions, like the DIETFITS study I just quoted, the difference there and what caused the weight loss was the change in people's eating habits. Their actual energy expenditure probably increased by 50 kilocalories per day. The calorie intake decreased by around 500 calories per day. That's where the return on investment is.