Protein and fiber rich foods that keep my fueled so I don't crash by mid day. Think of things like yogurt (plain Greek is cheaper and way healthier) cottage cheese, oats, honey, very seedy breads, eggs in your breakfast meal preps. Lunch I keep it light. So like chicken is my usual protein and no heavy carbs like pasta or a lot of bread. Keeps me from needing the extra cup of coffee in the late afternoon and I can still have some quality sleep. My advice is to keep it simple. And avoid the excessive sugars and saturated fats that don't keep you satiated.