To give it a car analogy, it feels like the weight loss discussion is asking: "Why are there so many automobile accidents?" Then come a lot of replies in that say "When you hit the brake, the car will slow down!" I feel like there are multiple things going on at different levels that so many people don't/can't hit the brake at the right time. That doesn't make the calorie-in-out statement false, and any solution will certainly involve reducing calories in. But, it suggests to actually get the weight of the overall population down, we need to look a bit more broadly.