It’s probably not because of the calorie “quality”, but moreso the total macro composition and your activity level. You said you switched from kitkats to protein bars, that’s like atleast 20g more protein and less fats right there. You switched from high sodium ramen, sweet treats and the biggest one alcohol, to lean meats like sardines, and vegetables. You also started having set meal times and started exercising more (walking).
w my new job I needed more sustainable energy, and I needed to incorporate walking more regularly, I switched kitkats for protein bars and started spending more $/effort to eat nutritional foods: sardines/veggies/salads/etc, I also did have to stop drinking cuz it didn’t make sense for me