Feeding children plain meat, fish or vegetables can significantly boost their mental performance. Children fed meals rich in nutrients and vitamins saw their IQ rise, whereas children under the age of four eating a diet of processed food, fat and sugar have lower brain power.  The brain grows fastest in a child’s first three years and a poor diet, associated with increased intake of processed foods, fat and sugar in early childhood may be associated with lower IQ at the age of 8.5 years.

A healthy diet may be associated with higher IQ and it is possible that good nutrition may encourage optimal brain growth.