Young Adults at Highest Risk of Overweight, Obesity over 10 Years

The risk of transition from overweight to obesity and to more severe obesity is highest among those aged 18- to 24-years-old, according to analysis of data from more than 2 million EHRs.

A landmark EHR analysis of data from more than 2 million individuals seen in 400 primary care practices in England found that the greatest risks for becoming overweight or developing obesity were among patients aged 18 to 24 years and that age is the most important sociodemographic factor for BMI change over the lifespan.

More specifically, researchers at the University College London (UCL) Institute of Health Informatics found that people aged 18 to 24 were 4 times more likely to become overweight or develop obesity over the 10 years to follow than adults aged 65 to 74. Younger persons who qualified as either overweight or obese at baseline also were at greater risk for moving to a higher BMI category (ie, from overweight to obesity or from non-severe obesity to severe obesity) than those classed as overweight or with obesity in any other age group.

“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,” said lead author Michail Katsoulis, MSc, PhD, a senior research fellow at UCL, in a UCL statement.

The findings were published in the Lancet Diabetes & Endocrinology.

Katsoulis and fellow researchers believe that obesity prevention policies would benefit significantly from targeting population groups at greatest risk for weight gain but point to wide gaps in understanding of the relative impact of age, sex, ethnicity, geography and “social deprivation” on weight gain. They yapped the emerging "data science opportunity" offered by longitudinal population-based EHRs, which offer valid measurements of weight and BMI changes and have the scale to allow evaluation of combined contribution of many factors.

The study analyzed anonymized primary care health records from 2 396 540 adults from 400 primary care practices with EHRs linked via a collaborative data sharing platform.

Eligible participants were aged 18–74 years, were registered at a general practice clinic, and had BMI and weight measurements recorded between Jan 1, 1998, and June 30, 2016, during the period when they had eligible linked data with at least 1 year of follow-up time. The final group of 2 092 260 eligible participants was 58% women and 76% White. Researchers had access to more than 9 million BMI measurements.

Katsoulis et al calculated longitudinal changes in BMI over 1, 5, and 10 years, and calculated the absolute risk and odds ratios (ORs) of transitioning between BMI categories using World health Organization categories: underweight, normal weight, overweight, obesity class 1 and 2, and severe obesity (class 3). Logistic regression analysis was used to estimate associations of demographic factors with BMI transitions and adjusted for variables including baseline BMI, family history of cardiovascular disease, diuretic use, and comorbidities.


The investigators report that young adult age was the strongest risk factor for weight gain at 1, 5, and 10 years of follow-up. When compared with those in the oldest age group (65–74 years), adults in the youngest age group (18–24 years) had the highest relative risk (OR, 4.22 [95% confidence interval (CI) 3.86–4.62]) and greatest absolute risk (37% vs 24%) of transitioning from normal weight to overweight or obesity at 10 years.

Similarly, when compared with the older age group, those in the 18–24 years age group had the highest relative risk (OR 4.60 [4.06–5.22]) and absolute risk (42% vs 18%) of transitioning from the overweight to the obesity BMI category, and the highest relative risk (OR 5.87 [5.23–6.59]) and absolute risk (22% vs 5%) of transition from class 1 and 2 to class 3 obesity.

A notable finding was that the association between values on an index of deprivation and transition to a higher BMI category was even more pronounced among individuals in the 18–24 years age group compared with older age groups

The association of other sociodemographic factors with weight gain over time was less pronounced, eg, OR of transitioning from normal weight to overweight or obesity for men versus women was 1.12 (95% CI 1.08–1.16); for Blacks vs Whites, 1.13 (95% CI, 1.04–1.24); and for people living in the most socially deprived vs least deprived areas 1.23 (95% CI, 1.18–1.27).

“Health systems, like the NHS, need to identify new ways to prevent obesity and its consequences,” said senior author Harry Hemingway, MBBS, professor of Clinical Epidemiology at the UCL Institute of Health Informatics, in the UCL statement. “This study demonstrates that NHS data collected over time in primary care holds an important key to unlocking new insights for public health action.”

“Young adulthood offers an important, and currently neglected, opportunity for both population-level prevention of the onset of obesity and the identification of individuals at high risk of weight gain for targeted interventions,” concluded the authors.

Reference: Katsoulis M, Lai AG, Diaz-Ordaz K, et al. Identifying adults at high-risk for change in weight and BMI in England: a longitudinal, large-scale, population-based cohort study using electronic health records. Lancet Diabetes Endocrinol. Published online September 2, 2021. DOI: