The team, led by Professor David Barker at the University of Southampton, has already been influential in showing the long-term impact on health of low birth weight. The scientists' work suggests that undernutrition in the womb and the resulting low weight at birth puts an infant at higher risk of heart disease, diabetes, depression and respiratory problems.
In the new study, they show that this trend is compounded during the early years of childhood as the infant grows rapidly to catch up on its slow growth in the womb.
"Our research shows that it is rate of weight gain, not the degree of fatness at any one time, which is the main predictor of future problems," said Professor Barker.
The researchers looked at the medical records of 8760 people born in Helsinki from 1934 through 1944. Their analysis, published in the 27 October issue of the New England Journal of Medicine (vol 353, issue 17, pp1802-9), showed that small size at birth, thinness at two years, and high body mass at 11 years were all associated with later risk of heart disease.
The findings are likely a result of the impact of early weight gain on long-term insulin processing, say the researchers.
On average, adults who had a coronary event had been small at birth and thin at two years of age and thereafter put on weight rapidly. This pattern of growth during childhood was associated with insulin resistance in later life. The risk of coronary events was more strongly related to the tempo of childhood gain in body mass index (BMI) than to the BMI attained at any particular age.
"Slow early development and undernutrition in the womb may programme a 'thrifty' metabolism, which includes insulin resistance that becomes inappropriate with adequate or excess nutrition in childhood," said Professor Barker.
Conversely, greater growth in babies of all sizes in the first two years was associated with a lower incidence of coronary events.
The study underscores the importance of maternal nutrition, and early infant nutrition.
"Those children that may be most at risk from later heart disease are effectively invisible," added Professor Barker. "You wouldn't be able to pick them out immediately in a primary school classroom as being at risk. You would need to monitor their body weight over a longer period."