Obesity cases rising fastest in young adults

A significant story is unfolding on the international scene. Obesity cases rising fastest in young adultsImage source, Getty ImagesByNick Triggle Health correspondentPublished3 minutes agoNew cases of obesity are rising fastest in younger adults in England, a study suggests. Rates of new diagnoses for people in their 30s were nearly 20% higher in 2024-25 than they were in 2019-20, according to the study published in The Lancet. For people in their 20s, new cases jumped by 16%.

These increases were higher than in older age groups - although the most common ages for diagnosis remained the 40s and 50s. But experts said the trend towards earlier diagnosis was worrying given obesity increases the risk of illnesses such as diabetes, heart disease and cancer. Alongside the age-group breakdown, the team also identified significant differences between different ethnic groups - earlier onset of obesity was more common in non-white people - while the areas with the highest levels of deprivation also saw steeper rises.

The Details

These patterns, when it comes to obesity, are well established, but the acceleration in new cases among younger adults was more unexpected, the researchers said. How weight-loss injections are turning obesity into a wealth issue Published29 September 2025Why the rapid rise? Lead researcher Robert Fletcher said while the study did not investigate the causes behind the rise, he felt there were three key factors.

He said adults in their 20s and 30s were ones who had grown up during a period when there was a boom in the unhealthy food market. "They have been surrounded by unhealthy food in their formative years. On our high streets there has been a proliferation of takeaways and fast food outlets and unhealthy food has been heavily advertised as these age groups have been growing up.

"He also said the pandemic followed by the cost of living crisis was likely to have had a bigger impact on younger age groups. "The stress of looking after children, while working from home and then being able to afford healthy food as inflation increased, has made healthier lifestyles more difficult," he added. Sarah Perman, from the Association of Directors of Public Health, agreed.

What Experts Say

She said unhealthier options now dominated "our supermarkets, corner shops and fast food outlets". "From infancy, children and young people are bombarded with advertising that encourages an unhealthy diet. "It is also far cheaper and easier for individuals to consume foods and drinks high in fat, sugar, and salt than healthier alternatives.

"Research by the Food Foundation has found healthy foods are twice as expensive per calorie than unhealthy foods. Katharine Jenner, of the Obesity Health Alliance, said the environment people in their 20s and 30s have grown up with has had a huge influence on "habit-forming behaviours".

The story has become one of the most prominent items on the global agenda.