Science challenges public attitudes as experts say obesity is not a failure of willpower
Despite widespread belief that weight is simply a matter of personal responsibility, growing evidence shows obesity is shaped by biology, genetics and an environment engineered for overconsumption.
Public attitudes towards obesity in the UK remain dominated by the idea that excess weight is the result of poor self-control, even as medical evidence increasingly contradicts that view.
Comments such as “just eat less” and “take personal responsibility” continue to dominate online discussions about weight loss. Research suggests these views are widely held offline too. A study published in The Lancet, examining attitudes in the UK, Australia, New Zealand and the United States has found that eight out of 10 people believed obesity can be entirely prevented through lifestyle choices alone.
However, clinicians and researchers working in obesity care argue this perspective overlooks decades of scientific evidence. Bini Suresh, a senior dietitian who has spent more than 20 years supporting people living with obesity, says many of her patients are motivated, informed and consistent in their efforts, yet continue to struggle.
“Obesity is often framed as a moral failing,” she says, “but that ignores the biological and environmental forces working against individuals.”
One of the strongest influences is genetics. Professor Sadaf Farooqi, a consultant endocrinologist at the University of Cambridge, explains that genes play a major role in regulating appetite, fullness and metabolism. Variations in these genes can make some people feel hungrier, feel less satisfied after eating or burn fewer calories than others, even when consuming the same foods. One appetite-regulating gene variant is thought to be carried by roughly a fifth of the global population.
Biology also helps explain why long-term weight loss is so difficult. Dr Andrew Jenkinson, a bariatric surgeon, describes the concept of a “weight set point” a range the body attempts to defend. When weight falls below this level, hunger increases and metabolism slows, encouraging weight regain. This process, designed to protect against starvation, can make dieting feel like a constant uphill struggle.
These biological pressures are amplified by the modern food environment. In the UK, more than one in four adults are obese, and over 60 per cent are overweight or obese. Ultra-processed foods are cheap, widely available and heavily marketed, while healthier options often cost significantly more. A report by The Food Foundation found healthier foods to be more than twice as expensive per calorie than less healthy alternatives.
The government has sought to address this through regulation. This includes new restrictions banning television advertising of foods high in fat, salt and sugar before 9pm and a complete ban on online promotions. Ministers argue the measures will help reduce exposure to unhealthy food marketing, particularly among children.
Yet critics say advertising controls alone will not reverse decades of rising obesity rates. Public health leaders point to urban design, time pressures, income inequality and constant exposure to food outlets as additional drivers of weight gain.
Debate continues over how responsibility should be shared between individuals and the state. While some commentators warn against excessive regulation, many experts argue that continuing to frame obesity as a simple failure of willpower risks deepening stigma and undermining effective treatment.
As Bini Suresh puts it: “Obesity is a complex, chronic condition shaped by biology and an environment engineered for overconsumption.
‘‘Willpower plays a role, but it is only one small part of a much bigger picture.”