Your editorial on cancers in under-50s ( 8 October ) rightly names food among the culprits. But the confrontation it calls for should be aimed less at obesity than at what produces it. Obesity is the intermediary; the exposure is a food system engineered for profit.

The Lancet's series on ultra-processed foods showed these products displacing traditional diets worldwide and driving chronic disease, and documented more than 200 interconnected lobby groups through which the industry organises its influence to block regulation.

I was diagnosed with bowel cancer at 51, narrowly escaping these statistics; the generations below me have eaten ultra-processed diets from birth.

Governments know what works: marketing restrictions, warning labels, fiscal measures, schools and hospitals free from ultra-processed food, and policymaking protected from industry interference.

Yvette Cooper should treat the companies that shaped our diets in the same way that her predecessors eventually treated tobacco: not as partners to consult, but as an industry to regulate. Prof Kent Buse hair, policy and prevention committee, World Obesity Federation The worrying rise in early-onset cancers underlines the urgency of government intervention on obesity. Our food system is broken when high-fat, -salt and -sugar options are consistently the most accessible and affordable.

Advances in cancer research and weight-loss drugs will play a key role in managing diet-related illness, but treatment alone cannot solve a public health crisis. We must fix the food environment driving obesity in the first place. That requires changing the incentives for large food businesses that make and market the food we eat.

The government's proposed healthy food standard sets out the most ambitious action for reforming the food environment to date, but progress has stalled since its announcement. It has the potential to reduce national obesity rates by about one fifth in adults and a quarter in children. Nothing else on the table comes remotely close to that.

The first step is establishing mandatory health reporting so that companies can no longer mark their own homework. Then we need clear targets for major food businesses to improve the health of what they actually sell. Ultimately, we cannot protect future generations from preventable diet-related disease until healthier food is the easiest and most affordable option. We cannot let our strategy be "wait for people to get sick and then put them on the drugs".

Hugo Harper Director, Nesta Cancer has become the greatest cause of death among people with type 2 diabetes in England and the problem of metabolic risk and cancer is one of the great threats to health. However, this is not known by health professionals or the 4 million patients with this condition.

Cancer screening programmes work effectively with informed participation. GPs and their practices can use the annual diabetes check to highlight the cancer prevention. Screening programmes and primary care can work together to prevent cancer, if resources are targeted in the best way. The World Cancer Research Fund report has added urgency – let's use it effectively. Dr Pawan Randev Former Cancer Research UK GP I read with interest Anna Bawden's article ( Cancer rates rising more quickly among younger people, international research finds, 6 October It seems that "lifestyle choices" are largely responsible for this, but I wonder just how much of a choice is open to us nowadays.

We can choose to drink less alcohol, not smoke, exercise more and eat more healthily, but our choice of healthy food is limited, as products become increasingly industrialised with the addition of chemical additives, and we have little or no control over environmental or agricultural pollutants. To all this we might add the stress of the increasing cost of living and difficulty in finding jobs.

I believe it is perhaps not so much a question of poor lifestyle choices, but a lack of lifestyle choices. Patricia Hampton Milan, Italy