First five years of a child’s life provide a critical window of opportunity for preventing overweight and obesity, Dutch study suggests
The first five years of a child’s life may be key to preventing overweight and obesity in years to come, say the authors of new research being presented at year’s European Congress on Obesity (ECO 2025).
The study found that a child’s body mass index (BMI) at the age of six is a better predictor of their risk of overweight or obesity at age 18 than their BMI at other points in their childhood.
Every one-unit increase in BMI at age six more than doubled (2.35 times) a child’s odds of being overweight or obese at 18. (BMI was adjusted for age and sex.)
The study also found that if a child with a higher BMI reached a healthier weight before the age of six, they were no longer at a higher risk of living with overweight or obesity in their late teens.
However, if they returned to a healthier BMI when they were six or older, they were still at higher risk of overweight and obesity.
This suggests that the first five years of a child’s life provide a critical window of opportunity for preventing overweight and obesity in young adulthood, says Jasmin de Groot, of Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
Ms de Groot and colleagues used data from an ongoing prospective cohort study1 in Rotterdam, the Netherlands, to track the BMI trajectories of thousands of children in the Netherlands.
Weight at birth (adjusted for gestational age and sex) and BMI at age two, six, ten, 14 and 18 years was available for 3,528 participants, 52.9% of which were female.
A child’s BMI generally increases with age. For this reason, the researchers used reductions at the rate in which BMI was increasing (i.e. a BMI that was growing more slowly) as an indicator of healthy growth – and of reaching a healthier weight – rather than a reduction in BMI.
Some 32.3%, 22.3%, 24.7% and 20.6% of the 3,528 children lived with overweight or obesity at the ages of 2, 6, 10 and 14 years, respectively.
Many of these children were still in the overweight or obese range at the age of 18. Of the children with overweight or obesity at the ages of 2, 6, 10 and 14 years, 32.5%, 53.9%, 57.2%, and 70.3%, respectively, still lived with overweight or obesity at 18 years.
A higher BMI at any point in childhood, regardless of earlier BMI, was associated with a higher chance of overweight or obesity at 18 years.
A high BMI at the age of six was particularly strongly associated with overweight and obesity at 18.
However, when the researchers split each age group into three groups based on their BMI, they found that if a child in the group with the highest BMI slowed down the growth of their BMI before the age of six, their odds of living with overweight or obesity at 18 were similar to those of a child with a stable, average BMI.
Reaching a healthier weight after the age of six did not have the same effect: the children with the highest BMIs were more likely to live with overweight or obesity aged 18 regardless of how their BMI changed from the age of six onwards.
The findings, say the researchers, emphasise the importance of monitoring BMI in early childhood.
Ms de Groot adds: “We need to understand how children grow and develop if we are to help future generations grow up healthier and give every child a chance at a happy, healthy life.
“Our research assists with this by showing that a child with overweight or obesity isn’t destined to live with overweight or obesity as a young adult – and that the first five years of a child’s life provide a fantastic opportunity to intervene and prevent them experiencing overweight and obesity in the years to come.”
Article Publication Date
11-May-2025
Childhood obesity can have long-term consequences on employment and study prospects, Swedish study finds
Individuals who lived with obesity as children are four times more likely to be on sick leave aged 25 than their peers in the general population
Individuals who lived with obesity as children are less likely to be in work or studying in their mid-20s than their peers, new research being presented at year’s European Congress on Obesity (ECO 2025) has found.
They are also more likely to be on long-term sick leave, the Swedish study of the long-term labour market outcomes of childhood obesity found.
“Rates of childhood obesity are higher in individuals from lower socio-economic backgrounds than in those from higher socio-economic positions,” explains Dr Emilia Hagman, of the Karolinska Institutet, Stockholm, Sweden.
“The reasons for this are complex but one contributing factor may be limited ability to afford healthy foods.
“We have previously shown that children with obesity are less likely to complete 12 years of schooling than those in the general population. This made us wonder to what extent that affected later labour market outcomes.”
Estimating socio-economic position in early adulthood is challenging, as income levels are often low when studying. As a result, the impact of childhood obesity on future employment, education, parental leave and long-term sick leave remains unclear.
To address this, Dr Hagman and colleagues used data from the Swedish Childhood Obesity Treatment Register and several national welfare registers to compare labour market outcomes in early adulthood of two groups of individuals: one that had lived with obesity in childhood and one from the general population.
Some 3,514 individuals who had lived with obesity as children were compared with 16,809 individuals from the general population, matched for sex, year of birth and living area. All were born between 1978 and 1996.
The participants were categorised into six groups: working, low-paid (this group earned less than “working” group), studying, parental leave, sick leave (receiving benefits for long-term sickness, early retirement or disability) or welfare recipient/other (this group included those who were unemployed).
At the age of 25, 59% of the childhood obesity group were working or studying, compared with 68% of the general population.
The rates of parental leave (3% vs. 2%) and low-paid work (22% vs. 22%) were similar between the two groups. However, long-term sick leave was much more common among those who had lived with obesity as children.
At the age of 25, 8.1% of the childhood obesity group were not working due to ill health, compared with 2.3% of the general population group. Overall, the individuals who lived with obesity in childhood had 4 times higher odds of being on long-term sick leave than working, compared to the general population comparators.
The study also found the degree of childhood obesity to be important.
Individuals who lived with class 3 obesity (the most severe form of obesity) in childhood were around three times more likely to be on sick leave (2.85 times) or in the “welfare recipient/others” group (2.97 times), rather than working, compared to those with class 1 obesity (the least severe form of obesity).
Dr Hagman says: “We initially expected that those who experienced obesity in childhood would be overrepresented in the low-paid group, as we know that children with obesity are less likely to complete at least 12 years of schooling than others, and so leave school with fewer qualifications. We also know that weight discrimination occurs in the labour market.
“Instead, we found that long-term sick leave emerged as an important contributor for not working. To understand the kind of ill health that contributes to this, more research is needed.
“However, we know from previous research that psychiatric conditions, such as depression, are more common among individuals that live with obesity.
“We have to raise awareness that obesity early in life can have long-term consequences, both for the overall health and for labour market outcomes.
“We know that a good response to obesity treatment in childhood decreases the long-term risk of several obesity-related outcomes, such as type 2 diabetes, hypertension and even premature mortality.
“However, more research is needed to determine if it also improves the children’s employment and study prospects as they get older.”
Article Publication Date
11-May-2025
