No, it's scientifically proven that eating too much isn't necessarily the problem; rather, it's the quality of the food you consume that determines obesity. If you eat too much unprocessed food, you won't gain as much weight as you would from eating processed food.

Many Americans visit Europe and are amazed that they can eat a lot without gaining weight.

The human body simply cannot process processed food. It's simply unnatural.

Sounds like you needed more healthy oils in your diet, not UPFs.

how exactly did you struggle with getting calories from vegetables? did you literally just eat lettuce?
Even just carrots have a perfectly reasonable amount of calories, and vegetables are notoriously easy to digest, so the idea of not being able to physically fit more seems wholly made up.