Our food products used to be different before modern agriculture took over. Food crops and livestock are more energy/calorie dense now than 100 years ago because of hormones, disease management, selective breeding/speciation, fertilizers/feed and other changes we made to agricultural production. It doesn't take processed foods to be the sole culprit here when the components of the modern diet have increased in caloric content by upwards of 500%. People weren't morbidly obese 100 years ago because their diet was extremely limited, less energy dense and they did a lot more manual labor and less eating overall. In some cases people were actually malnutritioned from all those factors combined. Sure processed foods are bad, but we can't lay the problem solely on just that one cause. Lifestyles have changed to be high stress, low sleep, sugar-boosted and caffeine fueled in order to keep up. Those play a huge role in the problem that didn't exist prior to the modern times. It's complicated.