Cheung and colleagues studied the psychological health of over 9,000 British adults born in 1958 until age 42 years. Birth weight and growth in childhood was measured and factors such as father's social class and maternal smoking were accounted for.
They found that people who had a higher birth weight and a faster weight gain from birth to 7 years old had a lower level of psychological distress into middle age.
Previous studies could only demonstrate such a relation up to the age of 26 years, they conclude.