I think you vastly underestimate soda consumption. There's some folks who legitimately almost don't drink water, and only drink soda instead. Switching to diet soda can easily be 300-800 calories gained back.
It's the same thing with beer, which is roughly the same calorie count as a soda of equivalent size. Folks switching from a 'regular' beer to light beer or (even better) liquor can easily drop weight due to the difference in calories between the two.
A pound of fat is ~3500 calories, so gaining 1 pound only requires you to eat (or, rather drink) ~24 sodas or beers over your maintenance rate of energy consumption.
Ah, you mean diet in the 'weight loss diet' sense. Yeah, I'd agree that generally if you're actively trying to diet full sugar soda is likely not going to be a main component.
Although, I will say that many MANY people have extremely poor education in terms of dieting... so there may not be the knowledge there.
I kind of just mean in general. Because weight loss for most people isn't about a diet that you do for a month or something. It's about what you eat forever.
You might be able to get away with drinking a ton of Coke if you're bulking and lifting in the gym or you're an avid cyclist, but for your average office jockey trying to get 2000-2500 calories in, if you get 500+ from soda you're really limiting what you can eat to meet your protein, fat, micronutrient needs.
It's the same thing with beer, which is roughly the same calorie count as a soda of equivalent size. Folks switching from a 'regular' beer to light beer or (even better) liquor can easily drop weight due to the difference in calories between the two.
A pound of fat is ~3500 calories, so gaining 1 pound only requires you to eat (or, rather drink) ~24 sodas or beers over your maintenance rate of energy consumption.