What products should I introduce into my diet to eat healthier meals?
Hard to say without knowing what you currently eat. A semi decent rule (although not without some criticism) is roughly 1/3rd fruit and veg, 1/3rd carbs and 1/3 protein/fat in your general diet.
You should speak to a nutritionist after a blood test. Nutrition should be individually fitted to maintain a balanced nutrition that fits your needs and abilities ( I mean allergies and stuff).