New cases of obesity are rising at the fastest rate among younger adults in England, according to a study published in The Lancet. Between 2019-20 and 2024-25, new diagnoses for individuals in their 30s increased by nearly 20%, while cases for those in their 20s saw a jump of 16%.
While these age groups experienced the most significant acceleration in new diagnoses, the most common ages for obesity diagnosis remained in the 40s and 50s. Experts express concern over this trend toward earlier diagnoses, as obesity is known to elevate the risk of serious health conditions including diabetes, heart disease, and cancer.
Demographic and Socioeconomic Factors
Beyond age, the research also highlighted disparities across ethnic groups and areas of deprivation. Earlier onset of obesity was found to be more common in non-white individuals, and regions with higher levels of deprivation also reported steeper increases in new cases.
Researchers noted that while these patterns in obesity are established, the rapid acceleration among younger adults was unexpected. Lead researcher Robert Fletcher suggested that adults in their 20s and 30s grew up during a period of significant expansion in the unhealthy food market, with increased exposure to takeaways, fast food outlets, and heavy advertising.
Fletcher also pointed to the impact of the COVID-19 pandemic followed by the cost of living crisis, which he believes disproportionately affected younger age groups. The stress of childcare, remote work, and the rising cost of healthy food likely made maintaining healthier lifestyles more challenging.
Sarah Perman from the Association of Directors of Public Health echoed these concerns, stating that unhealthy options now dominate many food retailers. She added that children and young people are continuously exposed to advertising promoting unhealthy diets, and that high-fat, high-sugar, and high-salt foods and drinks are often cheaper and more accessible than healthier alternatives. Research by the Food Foundation indicates that healthy foods can be twice as expensive per calorie compared to unhealthy options.
Katharine Jenner of the Obesity Health Alliance emphasized the significant influence of the environment on habit-forming behaviors for those in their 20s and 30s. She also suggested that the digital landscape, including food apps and social media use, may play a role, alongside pandemic-related disruptions to physical activity and other routines during a critical developmental period.
Study Methodology and Overall Trends
The study, conducted by teams from the University of Cambridge, the British Heart Foundation, and the George Institute for Global Health, analyzed 55 million adult NHS patient records. Individuals already recorded as obese were excluded from the analysis of new diagnoses.
Specifically, among adults aged 30 to 39, there were 24.1 new cases diagnosed per 1,000 people in 2024-25, up from 20.3 per 1,000 in 2019-20. For those aged 20 to 29, new cases rose to 20.3 per 1,000 from 17.5 five years prior. These represented the most rapid increases across all age groups, with rates of new cases actually falling in the 60-79 age bracket.
Researchers suggested this decline in older groups might be linked to the use of weight loss drugs, as these individuals may have greater affordability and access compared to younger demographics, given restricted NHS availability.
Overall, the proportion of people recorded as obese in England rose from 26.2% to 30.3% during the study period. Prof Sir Michael Marmot, a leading expert on inequality, described the findings as concerning and further evidence of widening inequalities since the pandemic.
A spokesperson for the Department of Health and Social Care stated that the government is implementing measures to address obesity, including new restrictions on junk food advertising and targets for healthy food sales.
Steve Lopez is the Editorial Page Editor for News Raise. He covers Health. He has won more than a dozen national journalism awards for his reporting and column writing at seven newspapers and four news magazines.
