And this is why it matters:
New research shows highest adult heart risk for 'invisible' primary school children
Research published today indicates that the risk of heart disease in adulthood is more strongly related to how quickly children gain weight between the ages of two and eleven than their actual body weight at any particular age. Scientists believe this is linked to differences in insulin processing in later life.
The British Heart Foundation (BHF) funded research, which is led by Professor David Barker of the University of Southampton, is published in the New England Journal of Medicine.
Professor Barker commented: "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. Those children that may be most at risk from later heart disease are effectively invisible - 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."
The research team looked at the medical records of more than 8000 people in Finland. Their analysis 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.
A path of growth that combined these factors was associated with the greatest risk of later heart disease. People who were small and thin up to the age of two and gained weight more quickly than their peers thereafter, catching up with, or even surpassing them by 11 years were most at risk. Adults that developed in this way were resistant to the effects of insulin and were most likely to later develop heart disease.
Conversely, greater growth in babies of all sizes in the first two years was associated with a lower incidence of coronary events.
"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," added Professor Barker.
Professor Barker and his colleagues at the Centre for the Developmental Origins of Health and Disease at the University of Southampton have pioneered the relationship between low birth weight and later heart disease. In this study the research team has been able to examine for the first time the long term effects of growth between birth and the age of two. They analysed the extensive medical records of 8760 Finns born between 1934 and 1944. Each individual in the study had 11 measurements of height and weight recorded between birth and 2 years.
The Southampton team worked closely with Professor Johan Eriksson in Finland, whose team examined more than 2000 of the group alive today, checking their glucose, insulin and cholesterol levels.
Peter Weissberg, Medical Director of the BHF said "This is interesting and important data that feeds into an evolving picture of how nutrition and early life may affect our adult health.
"Although this picture is not yet complete, this study tells us something about the way fat cells are laid down in this period of childhood, which seems to leave some of us at risk in later life.
"In the future, as we understand more about the biology, studies like this one will contribute to guiding healthcare advice and services from the womb to the grave."