A hearty midday meal can power you through the rest of the day. Farmers, construction workers and other people whose jobs require hard physical labor count on a big lunch to give them energy.
If you sit all day at work, you don’t use as much energy as someone with an active job, but you still can benefit by making lunch your biggest meal. You’ll be less likely to snack in the afternoon, you’ll burn off more calories during the day and your dinner can be smaller.
If you do decide to eat a big lunch, you might want to follow it with a walk of 15 minutes or so to counteract the sluggishness that sometimes follows a generous meal.