Lack of concentration or the inability to focus is a widespread concern, regardless of age, gender or country. Sadly, the average attention span today is only 8 seconds. Food is the fuel that controls your energy and mood, both of which can significantly influence your ability to concentrate. If you’re struggling to stay alert, then it’s time to start rethinking what you are eating. There are plenty of healthy foods that can optimize your concentration and boost your productivity during the day.