Unbalanced meals that are high in carbohydrates, proteins, and fats have all been associated with post-meal sleepiness. Foods that are highly processed and contain lots of simple sugars are also common culprits. Unbalanced meals that are high in carbohydrates, proteins, and fats have all been associated with post-meal sleepiness. Foods that are highly processed and contain lots of simple sugars are also common culprits.