- A Swedish study of more than 100,000 people found that children with overweight who reached a healthy weight by young adulthood had no extra risk of heart attack compared with those at a healthy weight throughout.
- Overweight at around age 20 was clearly linked to higher risk of coronary heart disease, whether it started in childhood or first appeared during puberty.
- People who developed overweight during puberty had an even higher heart attack risk than those who were overweight all the way from childhood.
Researchers at the University of Gothenburg analysed data from the BEST Gothenburg cohort, which includes school health records for children born between 1945 and 1968.
They looked at height and weight measured:
- in childhood (age 7 for girls and 8 for boys)
- in young adulthood (age 18 for women and 20 for men)
These records were linked to Swedish national registers to track who went on to have coronary heart disease events (fatal and non fatal heart attacks and related diagnoses) in adult life.
More than 103,000 individuals were included and followed from early adulthood into later life.
When childhood and young adult weight were analysed separately, both were associated with higher risk of coronary heart disease.
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But when both were put into the same statistical model, young adult overweight was what really drove risk, not childhood overweight on its own.
The researchers then divided people into four groups:
- normal weight in childhood and normal weight in young adulthood
- overweight in childhood but normal weight in young adulthood
- normal weight in childhood but overweight in young adulthood (pubertal onset overweight)
- overweight in both childhood and young adulthood
Key results were:
- Children with overweight who had a normal weight by young adulthood had no extra risk of coronary heart disease compared with those who were never overweight (hazard ratio about 0.98, statistically no different from 1).
- Those who were overweight in young adulthood, whether or not they had been overweight as children, had a clearly higher risk of later coronary heart disease.
- People who first became overweight around puberty or young adulthood actually had a higher risk than those who had been overweight all along.
In simple terms: carrying extra weight into adult life mattered more for heart attack risk than having been overweight only as a child.
What this means for children, families and services
For children with a higher body mass index, this study brings a hard truth and a hopeful message.
The hard truth is that overweight in young adulthood clearly increases the risk of heart attack in later life.
The hopeful message is that if childhood overweight is reversed before adulthood, the extra heart risk can be wiped out, at least in this large Swedish cohort.
For families, it underlines the value of:
- spotting rapid weight gain early
- supporting children and teenagers to move towards a healthier weight before they reach adult life
- focusing on sustainable habits rather than short term fixes
For health systems, including the NHS, it strengthens the case for serious investment in child and adolescent healthy weight services, particularly around the pubertal years where new overweight appears to carry the highest risk.
