Four-fifths of middle aged adults are putting themselves at risk of disease as busy lives and desk jobs make it increasingly hard to stay healthy, experts have said.
Eighty-three percent of 40 to 60 year-olds are either drinking too much, are inactive or are overweight, Public Health England (PHE) said.
Officials said that nine in 10 men (87%) and eight in 10 women (79%) are not doing enough exercise, exceeding the recommended limits for alcohol or are either overweight or obese.
Figures taken from the Health Survey for England show that 77% of men and 63% of women in middle age are either overweight or obese - with the rate of obesity shooting up 16% in the last two decades.
The diabetes rate among this age group also doubled in this period in England, PHE said.
Meanwhile, many are also not being physically active and drinking too much.
The health body is encouraging adults to take its One You - How Are You health quiz which may highlight problems and areas for improvement.
People who take the quiz and are flagged as having a problem are directed to apps including Couch to 5K, Alcohol Checker and Easy Meals
"The demands of modern day living are taking their toll on the health of the nation, and it's those in middle age that are suffering the consequences most, as their health reaches worrying new levels," said Professor Sir Muir Gray, clinical adviser for PHE's One You lifestyle campaign.
"Over 15 million Britons are living with a long term health condition, and busy lives and desk jobs make it difficult to live healthily.
"But just making a few small changes will have significant benefits to people's health now and in later life."
Professor Kevin Fenton, director of health and wellbeing at Public Health England, said: "People are busy with work, with families, with the daily grind and sometimes their own health is the least of their priorities.
"The How Are You Quiz will help anyone who wants to take a few minutes to take stock and find out quickly where they can take a little action to make a big difference to their health."
Dan Howarth, head of care at Diabetes UK, added: "We know that people often bury their heads in the sand when it comes to their general health but the consequences of doing nothing can be catastrophic."