> You left out the key word in that sentence, which should have appeared after “vastly”. I assume you mean easier, but in fact that’s not true for a lot of people.

Not sure I agree with that. I think it's probably true that adopting even a minimal exercise regimen is easier than adjusting diet, for most people.

But actually turning that new exercise regimen into a calorie deficit is significantly harder. Not only do you have to exercise probably quite a bit per week to get you into a deficit, you have to actively work to not eat more. If you start an exercise regimen, I guarantee you're going to be hungrier, and unless you're very strict with yourself, you can easily eat enough extra to wipe out most or all of the new calorie "savings".