Approximately 10% (£10 billion per year) of the UK NHS budget goes towards treating type 2 diabetes and related illnesses. This percentage is expected to rise over the coming years. More info can be found here https://www.nhs.uk/news/diabetes/diabetes-cases-and-costs-predicted-to-rise/
Type 2 diabetes is an entirely preventable disease. It is also largely reversable.
People who have made an effort to look after themselves should not have to pay for those that have not.
The £10 billion spent on treating type 2 diabetes and related illnesses could be better spent on education, infrastructure (electrical vehicle charging network, roads, tunnels, bridges, railways, trams, airports, flood prevention, etc.), other areas of healthcare, research, etc.
In addition to the direct money spent on treating there is the indirect money lost, e.g. lost productivity, lost tax revenue, etc.
The UK government should put the following policy in place.
In 5 years, the NHS will charge patients for the treatment of type 2 diabetes and related illnesses.
This gives people plenty of time to change their lifestyle and reverse any type 2 diabetes related illnesses.
If people chose not to change their lifestyle then they can pay for their treatment or take out insurance to cover the cost of their treatment.
Some may view this as tough medicine, but the current situation is not sustainable.