By Rachel Martinez, The Appleton Times
LONDON — As Britain grapples with an obesity crisis affecting more than one in four adults, a new government ban on junk food advertising took effect today, aiming to curb the promotion of unhealthy eats on television before 9 p.m. and entirely online. The move comes amid growing recognition that weight management is far more complex than simple self-control, challenging long-held beliefs that obesity stems primarily from a lack of willpower.
The misconception persists widely. In a study published in the medical journal The Lancet, eight out of 10 people in the UK, Australia, New Zealand, and the US said obesity could be entirely prevented by lifestyle choices alone. Reader comments under a recent article on weight-loss injections echoed this sentiment, with 1,946 responses including phrases like "Fat people just need more self-control," "It's about personal responsibility," and "It's simple, just eat less."
But experts argue this view oversimplifies a multifaceted issue. Bini Suresh, a dietitian with 20 years working with obese and overweight patients, expressed frustration: "I frequently see patients who are highly motivated, knowledgeable and trying consistently yet still struggling with weight." Dr. Kim Boyd, medical director at WeightWatchers, agreed, stating, "Terms like 'willpower' and 'self-control' are the wrong words. For decades people have been told to eat less and move more and they will lose weight... [But] obesity is much more complex."
At the heart of the debate is biology. Prof. Sadaf Farooqi, a consultant endocrinologist treating patients with severe obesity at Cambridge University Hospitals, explained that genetics play a significant role. "The amount of weight people gain is significantly influenced by their genes and those genes are relevant for everybody," she said. Certain genes affect brain pathways regulating hunger and fullness, with variants making some individuals feel hungrier and less full after eating.
One key gene, MC4R, which promotes overeating and reduces satiety, is mutated in about a fifth of the global population. Prof. Farooqi added, "Other genes affect metabolism – how quickly we burn energy. That means some will gain more weight and store fat from eating the same amount of food, than other people do, or they will burn less calories when they exercise." She estimates thousands of genes influence weight, though only 30 to 40 are well-understood.
Beyond genetics, the concept of a "set weight point" complicates efforts to slim down. Andrew Jenkinson, a bariatric surgeon and author of Why We Eat Too Much, described it as the weight the brain perceives as ideal, determined by genetics and environmental factors like food availability, stress, and sleep. "This [set weight] is determined by genetics, but also by other factors, such as your food environment, stress environment and sleep environment," he said.
According to set point theory, the body resists changes like a thermostat. If weight drops below this point, hunger intensifies and metabolism slows. Jenkinson illustrated with an example: "For instance, if you're 20 stone and your brain wants you to be 20 stone and you go on a low calorie diet and lose two stone, your body's reaction to that is just the same as if you were starving." He noted, "It's going to have that reaction of voracious appetite, food-seeking behaviour and a low metabolism. These appetite signals are profoundly strong. They're as strong as a thirst signal, they're there to help us survive… A voracious appetite is something that's really, really difficult to ignore."
Hormones like leptin, produced by fat cells, signal the hypothalamus to regulate appetite and metabolism. However, in modern environments, high insulin levels from frequent eating can dilute this signal, Jenkinson explained. The good news, he added, is that the set point can shift gradually through sustained changes: improved sleep, stress reduction, and consistent healthy habits, akin to slowly resetting a thermostat.
While biology sets the stage, the environment has fueled the crisis. The proportion of UK adults overweight or obese has risen steadily, with a 2025 Health Foundation analysis showing over 60% in that category, including 28% obese. Prof. Farooqi attributed this to an "obesogenic environment" of affordable ultra-processed foods, aggressive marketing, larger portions, and limited physical activity opportunities due to urban design and time constraints. "[As a result] we have become more obese as a population and, of course, those with a greater genetic propensity to put on weight have done so," she said.
Public health officials highlight everyday exposures. Alice Wiseman, public health director for Newcastle City Council and Gateshead, observed from her office: "There are coffee shops, bakeries and takeaways. You can't go to school or work without passing a food place. Visibility matters – if you pass lots of takeaways on your way to work, you're more likely to buy one. Your body's almost reacting to the food around it." In Gateshead, no new hot food takeaway permissions have been granted since 2015, but the national industry is booming, valued at over £23 billion annually.
Advertising exacerbates the issue. The latest Ofcom Communications Market Report shows UK food ad spending dominated by high-fat, high-salt, high-sugar products like confectionery, sugary drinks, fast food, and snacks. A Food Foundation report last year found healthier foods more than twice as expensive per calorie than unhealthy ones, straining low-income families. Wiseman noted, "In families where money is tight it is difficult to afford to eat healthily. I'm not saying personal responsibility doesn't have a role to play. But when you think about it, you have to ask what has changed? We haven't suddenly got less willpower."
Suresh reinforced this: "We're living in an environment engineered for over-consumption. Obesity is not a failure of character. It's a complex, chronic condition shaped by biology and a highly obesogenic environment. Willpower alone is not enough and framing weight loss as solely a matter of discipline does harm."
Not everyone dismisses willpower entirely. Prof. Keith Frayn, author of A Calorie is a Calorie, acknowledged environmental changes: "It is the environment that has changed, not their willpower or anything else." Yet he cautioned, "I worry that dismissing 'willpower' makes it too easy to resign oneself to being at a weight that may not be what is desired, or best for health." He cited the National Weight Control Registry in the US, with over 10,000 participants who maintained weight loss, describing it as "hard," and suggested they would be "quite affronted" if told willpower played no role.
The role of regulation sparks debate. Wiseman supports measures like today's ad ban and curbing promotions such as buy-one-get-one-free deals, which encourage impulse buys. However, Gareth Lyon, head of health and social care at the right-leaning Policy Exchange think tank, opposed further legislation: "You can't legislate people into shape. Bans and taxes on the foods that people enjoy eating are effective only in making life harder, less enjoyable and more expensive for people at a time when Britain is already struggling with the cost of living."
Christopher Snowdon, head of lifestyle economics at the Institute of Economic Affairs, another right-leaning group, viewed obesity as an "individual problem." "[Obesity] is because of choices made by that individual," he argued. "So ultimately, you can't go much beyond the individual. I find it a fairly bizarre idea that it's the government's responsibility to make people slimmer. I'd like to see a serious independent evaluation of these policies and if they don't work they should be repealed."
Psychologists offer nuance on willpower. Dr. Eleanor Bryant of Bradford University said it's not constant: "It's affected by your mood, how tired you are and, in terms of eating, how hungry you are." She distinguished flexible from rigid approaches, noting flexible thinkers recover from slips without bingeing, leading to better success. Exercising willpower around food is particularly tough, she added.
Suresh suggested education empowers: "When these patients understand that their struggle is rooted in biology, not lack of discipline, and are supported with structured nutrition, consistent meal patterns, psychological strategies and realistic goals, their relationship with food improves markedly." As Britain evaluates today's ad restrictions and broader strategies, the conversation shifts from blame to comprehensive support, recognizing obesity's roots in biology, environment, and society for more effective, compassionate solutions.