When you pre-cook your meals you are much less apt to make unhealthy choices. I find that when I do some preplanning I save time and money for the week. What I will usually do is buy chicken breasts in bulk (which is usually cheaper). I will also buy some fish and vegetables (fresh and/or frozen), which ever is on sale.
On Sunday afternoons I will set some time aside to cook for the week. I will usually throw some chicken on the grill (which helps keep the house cool during the summer months). While that is grilling I will either bake or put the fish on the grill at the same time. While those are grilling I will steam about 2-3 cups of brown rice in a rice steamer. Doing this small preparation enables me to have healthy choices and some much needed free time during my hectic week!