We get up in the morning and become more and more active. Then we get to a point when, it seems, the sun gets stuck high in the sky, so we can have either activity or stagnation. What we choose for lunch determines whether we become more active in the afternoon or stagnate. Now many people have hypoglycemia and become useless in the afternoon. They have to start out in the morning and do as much as they can, be as productive as possible until they get to that point, and that is it for the day. Then they just kind of coast and try to get a good start the next day.
If you want to be active in the afternoon, there are two key points; beginning lunch at noon rather than at one or two, and eating a simpler rather than more elaborate meal. The sandwich is the lunch food which has conquered the world. It is very unique, very ingenious and good for lunch. Of course this depends on the filling, how much, the type of bread, etc. Some good sandwich ideas are humus or steamed tofu. You can come up with many bean or vegetable based sandwiches. In macrobiotics we have introduced rice balls, brown rice with some umeboshi plum in the center and toasted nori wrapped around the outside. That is very good and very simple. We should look for things that are more simple and light but also nourishing and complete.
If you want to have a leisurely afternoon, then have an elaborate lunch.
The meal is a natural cycle, like the sun or the moon.