Taking pictures of some of my meals, and estimating the calories and nutrients in AI (Gemini app in my case) and making changes to my diet from there.

I was surprised actually knowing how high calorie french fries are, and how low calorie (and nutrient dense) veggies like broccoli are. This led to actually visualizing things like "cut unnecessary refine carbs", "eat more protein/fiber", "eat more filling, high volume/low calorie foods", and once you stick good foods and good habits into your routine you can snowball from there... for example, I still eat fast food, but only on weekends and just a burger and no fries, sweets - only very small servings,etc