Yesterday, I read a fascinating article from the BBC regarding willpower and weight loss, exploring why some people find it harder to lose weight than others. Based on that piece and supplementary research, it becomes clear that the traditional narrative around obesity requires a major update.
For decades, the cultural understanding of obesity in the UK has been deceptively simple: it is viewed as a failure of character. The prevailing logic suggests that if you are overweight, you simply lack the discipline to “eat less and move more.” This view is pervasive; a recent study found that 80% of people in the UK, US, and Australia believe obesity is entirely preventable through lifestyle choices alone. Yet, the reality on the ground paints a starkly different picture. In England, 64.5% of adults are now overweight or living with obesity, a figure that has risen steadily over the last decade. As millions can attest, if weight loss were solely about willpower, these statistics would look very different. Consequently, a growing chorus of medical professionals, geneticists, and dietitians are now dismantling the “eat less, move more” mantra, arguing that framing obesity as a choice is not only scientifically inaccurate but actively harmful.
The most profound challenge to the idea of personal responsibility comes from our own biology. Professor Sadaf Farooqi, a consultant endocrinologist at Cambridge University, notes in the BBC article that while our genes have not changed in the last few decades, they dictate how we survive in the modern environment. She explains that weight gain is significantly influenced by genetic variants which make certain individuals feel hungrier and less likely to feel full after eating.
Three key biological players stack the deck against weight loss. First is the MC4R gene; a mutation carried by roughly 20% of the population disrupts the brain’s ability to sense fullness, creating a drive to eat that is not born of greed, but is an imperative as strong as thirst. Second is the “thermostat” effect described by bariatric surgeon Andrew Jenkinson. The brain defends a specific weight range (a “set point”); if you diet below this, the body interprets it as starvation, slowing metabolism and ramping up hunger hormones like ghrelin. Finally, the microbiome plays a vital role. Recent research suggests that the gut flora of individuals with obesity may be more efficient at extracting energy from food, meaning two people eating the exact same meal might absorb significantly different amounts of calories.
If biology loads the gun, the environment pulls the trigger. Public health experts describe the UK as “obesogenic” – engineered for over-consumption. As noted in the BBC article, the visual bombardment of food cues, such as passing numerous takeaways on your daily commute, triggers a physiological reaction to the food. This is compounded by a stark economic reality: healthier foods are now more twice as expensive per calorie than less healthy alternatives. Consequently, obesity is not distributed equally, being significantly more common in deprived areas (37.4%) compared to affluent ones (19.8%). The psychology of poverty creates a “scarcity mindset,” creating a focus on immediate survival that makes the gratification of cheap, energy-dense food difficult to resist.
Perhaps the most damaging aspect of the “willpower myth” is the stigma it generates. Framing weight loss as a matter of discipline is unrealistic and unfair. Societal judgment does not just hurt feelings; it harms physiology. Research shows that weight discrimination triggers the release of cortisol, the body’s primary stress hormone, which is linked to increased abdominal fat storage and cravings for high-sugar comfort foods. Furthermore, sleep deprivation – common in our high-stress society – disrupts the hormonal balance even further by lowering leptin (the satiety hormone) and raising ghrelin (the ‘hunger’ hormone.
Does this mean willpower is irrelevant? Not entirely, but its definition needs an update. In the BBC article, Dr Eleanor Bryant, a psychologist, distinguishes between “rigid” and “flexible” willpower. Rigid willpower sees things in black and white; eating one biscuit is viewed as a total failure, leading to “disinhibited eating” where the person consumes the whole packet. This phenomenon is known in psychology as the “abstinence violation effect,” where a minor lapse leads to guilt, shame, and self-blame, causing the individual to abandon their plan entirely. Conversely, flexible willpower acknowledges the slip-up but stops there. While flexible willpower is statistically more successful, relying on it alone is difficult because biology eventually takes over.
So, what actually works? No single diet works for everyone. While calorie restriction, Mediterranean-style diets, and increased plant intake can help, long-term adherence is tough. Exercise is vital for health and maintenance, but rarely enough for significant weight loss on its own. Behavioural therapies – like cognitive-behavioural therapy – are proven to boost success, especially when they focus on flexible, realistic goals. Crucially, even if exercise does not move the scale, it improves heart health, longevity, and quality of life.
The landscape of treatment is shifting towards pills and policy. The NHS is beginning to utilise new medications, such as GLP-1 receptor agonists (like semaglutide), which mimic fullness hormones. On the policy front, the government is attempting to intervene with bans on junk food advertising before 9pm. This has sparked fierce debate between “interventionists,” who argue you must remove the environmental traps that make healthy living impossible, and “libertarians,” who argue that obesity remains an individual problem and that bans merely make life more expensive.
In conclusion, the science is clear: obesity is not a simple choice, but a complex, chronic disease driven by genes, hormonal signals, and environmental pressures. If you have made losing weight your New Year’s Resolution, do not get disheartened if healthy eating and exercise do not yield the large weight loss you were hoping for. Weight is not a perfect marker of health; it does not reflect body composition, cardiovascular fitness, or metabolic health. Improvements in physical health and function and mental well-being occur independently of changes on the scale. Healthy eating and exercise improve your life in ways a simple number cannot measure, and these outcomes matter far more than your weight.
Focus on eating a healthy, balanced diet and engaging in regular physical activity/exercise for the genuine improvements they bring to your health and quality of life. If these habits also help you shed a few pounds, consider it a welcome bonus.
Links
The BBC article can be found here: https://www.bbc.co.uk/news/articles/c2084q9079po
Przybyłowski, A., Górski, M., Gwioździk, W. & Polaniak, R. (2025) ‘Redefining obesity: A narrative review of diagnostic evolution, therapeutic strategies and psychosocial determinants’, Healthcare (Basel), 13(16), p. 1967. https://pmc.ncbi.nlm.nih.gov/articles/PMC12385716/#:~:text=Obesity%20is%20increasingly%20recognized,multifactorial%20disease%20requiring%20individualized
Westbury, S., Oyebode, O., van Rens, T. & Barber, T.M. (2023) ‘Obesity stigma: Causes, consequences, and potential solutions’, Current Obesity Reports, 12(1), pp. 10–23. https://pmc.ncbi.nlm.nih.gov/articles/PMC9985585/#:~:text=obesity%20stems%20from%20a,are%20outside%20an%20individual%E2%80%99s
