First of all a home cooked meal on average is going to have a lot less sodium and processed sugar in it so it is a lot healthier. There is also on average less fat and preservatives in a home cooked meal.
The other difference is the cost. A home cooked meal can cost as little as $2.00 per person while eating at a fast food restaurant costs and average of $4.00 per person. That's double!!
Studies have also shown that people are a lot less likely to get food poisoning when they eat at home than when they eat out. Generally your kitchen is less contaminated than those of the average restraint.
Last but not least, I don't know about you but I am often disappointed at the food I receive from restaurants, especially fast food places. It never looks or tastes as good as it should.