Toddlers who have a diet high in processed foods may have a slightly lower IQ in later life, according to a British study described as the biggest research of its kind. The conclusion comes from a long-term investigation into 14,000 people born in western England in 1991 and 1992 whose health and well-being were monitored at the ages of three, four, seven and eight and a half. Three dietary patterns emerged: one high in processed fats and sugar; a “traditional” diet high in meat and vegetables; and a “health-conscious” diet with lots of salad, fruit and vegetables, pasta and rice. When the children were eight and a half, their IQ was measured. Results show that children whose diet was predominantly based on processed food at age three tended to have a lower IQ at eight-and-a-half years, regardless of whether or not their diet had improved in the meantime. In contrast, a healthy diet at three years of age was associated with a higher IQ in later childhood. The type of food the children ate between the ages of four and seven did not seem to affect their IQ.