Being the eldest child has many advantages, such as having your parents full attention and avoiding cast-off clothes.
But researchers have warned being the first out the womb also brings its own health woes.
For according to a study from the University of Auckland, firstborns are at greater risk of developing diabetes and high blood pressure.
First-borns like HRH The Duchess of Cambridge (right) are more likely to be taller and slimmer than their siblings (Pippa, left). But scientists suggest they may also have a higher risk of diabetes, at least during childhood
This may be because younger children benefit from physical changes in their mothers' uterus that take place during the first pregnancy.
As a result of these, the nutrient flow to the foetus tends to increase during later pregnancies.
The researchers found that insulin resistance was 21 per cent lower in firstborn children when compared to their younger siblings. This meant they had greater difficulty absorbing sugars into the body. Eldest children also had a higher daytime blood pressure on average.
Study author Wayne Cutfield said: 'Although birth order alone is not a predictor of metabolic or cardiovascular disease, being the first-born child in a family can contribute to a person's overall risk.'
The research findings may have significant public health implications for countries with a one-child policy like China, and western societies where family sizes are shrinking.
The team studied 85 children who were aged between four and 11. The 32 youngsters who were first borns had a 21 per cent reduction in insulin sensitivity and a 4 mmHg increase in blood pressure.
However, the oldest and only children tended to be taller and slimmer than their later-born counterparts. These findings remained true even when their parent's BMI - a height and weight measurement - was taken into account.
The researchers focused on children because puberty and adult lifestyle can affect insulin sensitivity.
'Our results indicate first-born children have these risk factors, but more research is needed to determine how that translates into adult cases of diabetes, hypertension and other conditions,' Cutfield said.
The article will appear in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).
Read more: http://www.dailymail.co.uk/health/article-2278154/First-born-children-likely-diabetes--taller-slimmer-too.html#ixzz2KtcNnVbT
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