MPs have criticised the Department of Health and the NHS in England for being "too slow" to act in preventing and treating diabetes.
A report by the Public Accounts Committee says variations in the care of both type 1 and 2 diabetes mean the annual cost to the health service will continue to rise.
For people aged 16 and over the bill currently stands at £5.5bn a year.
An NHS England spokesman said "diabetes care [was] better than ever".
But he also said the obesity-fuelled jump in type 2 diabetes threatened to "overwhelm GP services".
"...[It] puts the spotlight firmly on the need for no-holds-barred national action on prevention by the NHS, government, employers, schools, and in particular the food industry," he added.
'Not keeping pace'
The committee said the number of adults in England with diabetes has risen to more than 3 million, and was going up by almost 5% every year.
The government and NHS England had portrayed an "unduly healthy picture" of the state of diabetes services, it added.
Most of the £5.5bn-a-year cost is spent on complications from diabetes, such as heart and kidney disease, blindness and nerve damage, leading to amputations.
These can be minimised by catching the disease early, and managing blood glucose, blood pressure and cholesterol.
But the committee said that part of the problem was there were "unacceptable variations" in education, care and treatment of patients.
Moreover, only 60% of patients receive the annual checks recommended to keep them healthy and prevent long-term complications.
The report also said diabetes specialist staffing levels in hospitals "are not keeping pace" with the increasing percentage of beds occupied by diabetes patients.
'Targets not met'
It said: "The percentage of beds in acute hospitals in England occupied by people with diabetes continues to rise, from 14.8% in 2010 to 15.7% in 2013.
"However, the level of diabetic specialists has not significantly changed over this period. In 2013, nearly one-third of hospitals in England taking part in the audit had no diabetes inpatient specialist nurse and 6% did not have any consultant time for diabetes inpatient care.
"NHS England told us that an increase in nursing numbers isn't likely in the next year or two."
Meg Hillier, chairwoman of the committee, said: "The NHS and Department for Health have been too slow in tackling diabetes, both in prevention and treatment.
"The number of people with diabetes is increasing, as is the number of patients who develop complications. It is a very serious condition that can have a huge impact on people's lives."
She said taxpayers must have confidence that support is available when and where they need it, "rather than by virtue of where they live".
What is diabetes?
- A chronic disease, which occurs when the pancreas does not produce enough of the hormone insulin, or when the body cannot effectively use the insulin it produces
- This leads to an increased concentration of glucose in the blood (hyperglycaemia)
- Type 1 diabetes is characterised by a lack of insulin production
- Type 2 diabetes is caused by the body's ineffective use of insulin, and often results from excess body weight and physical inactivity
The government has introduced a new NHS Diabetes Prevention Programme to try to limit the number of people developing type 2 diabetes. The programme will encourage people to lose weight and exercise.
Being overweight is the main risk factor for type 2 diabetes, and 90% of adults with type 2 diabetes are overweight or obese.
But the committee said "by itself, this [the programme] will not be enough to stem the rising number of people with diabetes".
A Department of Health spokesman said "big improvements in diabetes care" had been made, but added: "Any variation in care, as this report highlights, is deeply concerning.
"That's why we are creating a national diabetes prevention programme, the first of its kind in the world, so that we help people avoid developing this devastating condition in the first place."