There are several sayings in fitness circles that are similar to this: "You can't outrun your fork." Diet is the primary reason people are obese, not lack of exercise.
I can.
People who can't outrun their forks aren't running hard enough.
Hunting down a lot of calories and eating them is part of being a mammal. I bicycled across North America one fall on a mostly mountain route. Four times a day I ate full meals and added as many Dove bars as I could without being sick in between. I biked up and down hills with 30kg of gear all day. And I lost a lot of weight.
Sure it hurts to work that hard, but it's supposed to hurt a little. Being comfortable all the time isn't part of being a mammal.
By the way, if anyone wants to attempt an unsupported hike of the John Muir trail, send me an email and I will be happy to give you some advice.
The first time I came to China, I didn't know how to find palatable food. (Yes, this was something I worried about beforehand.) Over the course of three months, I lost 15 pounds.
I had been variously described, before that point, as "thin", "stick-thin", and "skeletal".
When my dad picked me up at the airport afterwards, he was shocked. He said I looked like I was literally starving to death, which in a limited sense was true. I spent a lot of those three months visualizing pizza.
Was it the perfect diet? I'm sure the approach (just refuse to eat what's available) works. But it was a truly awful experience. Not recommended to anyone.
Your anecdotate is just a silly brag that adds nothing to the discussion.
Not sure if it's true, but it's at least as scientific as "can't outrun your fork".
I haven't bothered to check if there's scientific literature that proves ingesting calories is easier than burning them, but I think you'd struggle to find a scientist or sane person who doesn't feel that generally it's orders of magnitude easier.
With this interpretation, exercising and eating adequately are very strictly related, I'd say they have the same root.
But also from a more physical point of view, nutrition is also a function of exercise, since there are many needs of the body which are function of it. So it goes both ways, I wouldn't say one of them is primary.