What I do is buy what everyone likes to eat. I usually need to cook 2 or 3 different meals. I like healthy food, and the others don't so much.
If you want to eat healthy, I would go with protein, like chicken, and fish. Fresh vegetables, and fruit are best. Frozen fruits, and vegetables, are better for you, then the canned vegetables. Canned food has a lot of sodium in it. If you like hamburger, I would go with the ground turkey. Turkey is healthy. Red meat has a lot of fat in it. If you use butter, get low fat butter. Oil use olive oil. If you use regular oil it doubles the calories on your food.