18-24 year olds at highest risk of weight gain

Being a young adult aged 18 to 24 is a more important risk factor for weight gain than sex, ethnicity, geographic region, or socioeconomic area characteristics, according to a new study.

The study, published in The Lancet Diabetes & Endocrinology, found 18-24 year olds were at highest risk of becoming obese in the next in the next decade of their life than any other age group. The researchers said obesity prevention policies should target this group and they have published for the first time an online tool for the public to calculate their risk of weight change over the next 1, 5, and 10 years based on an individual’s current weight and height, age, sex, ethnicity and socioeconomic area characteristics. The online tool is available at


The study led by researchers at UCL, the University of Cambridge, and Berlin Institute of Health at Charité –Universitätsmedizin Berlin (BIH) also found the risk of gaining weight is not only highest in the youngest adult age group, but steadily decreases with age.

Researchers looked at anonymised primary care health records from more than 2 million adults (with more than 9 million measurements of BMI and weight) in England between 1998 and 2016 to investigate the risk of weight changes at different ages and among different groups.

They found that people aged 18 to 24 were four times more likely to become overweight or develop obesity over the next 10 years than those aged 65 to 74. Young adults classed as overweight or obese were also more likely to move to a higher BMI category (from the overweight category to obesity or from non-severe obesity to severe obesity) than those classed as overweight or with obesity in any other age group.

Speaking about the online tool, co-senior author Professor Harry Hemingway (UCL Institute of Health Informatics and BIH Fellow) said: “Calculating personal risk of transitioning to a higher weight category is important as the Covid-19 pandemic collides with the obesity pandemic: people are exercising less and finding it harder to eat healthy diets during lockdowns.”

Lead author Dr Michail Katsoulis (UCL Institute of Health Informatics) said: “Our results show clearly that age is the most important sociodemographic factor for BMI change. Young people aged 18 to 24 have the highest risk of BMI gain, compared to older people. We also found that among individuals with obesity, those aged between 35 and 54 had the highest risk of not losing weight compared to other adults.”

The authors provide a YouTube video explaining the findings at https://www.youtube.com/watch?v=4JefRvdHSqs.

Image by New Africa | Adobe Stock