Medical science is constantly finding that humans are omnivores who need a wide variety of foods in order to function properly.
The ideal eating plan for a human includes healthy fats, animal and plant proteins, moderate grain intake and a large selection of fruits and vegetables.
Our modern lifestyles tend to ignore these findings and trade them for convenience products that cater to our hectic schedules and desire for comfort.
So while we all know that we need to eat a balanced diet (admit it, you know it!), we generally do not do it.