Few people know and understand the ­government's guidelines on healthy eating, smoking and drinking despite the millions of pounds spent on awareness campaigns, it emerged today.

Data from the annual Health Survey for England revealed that although obesity has nearly doubled in the last 14 years, two-thirds of men and women do not know the amount of exercise they should be taking. Only 27% of men and 31% of women eat the recommended five portions of fruit and vegetables a day.

Less than a third knew the maximum amount of alcohol they should drink a day, the report found. And only 14% of men and 11% of women could always correctly identify a portion of fruit or vegetables.

There was also no evidence that people are smoking less specifically as a result of the ban on smoking in public places introduced in July 2007. However, saliva samples taken to measure cotinine levels (an indicator of exposure to nicotine) suggested fewer people are lighting up.

The survey of data and attitudes in 2007, published by the NHS Information Centre, showed that obesity has steadily climbed over the last 14 years.

In 1993, 13% of men and 16% of women were obese, but by 2007 the figure was 24% for men and women. The proportion of people overweight has remained fairly constant at around 37%. Among children, obesity has risen from 11% of boys and 12% of girls in 1995 to 17% and 16% in 2007.

Despite their lack of knowledge of what the government recommends, people's consumption of fruit and vegetables and exercise levels have gone up, the survey said.

In identifying a portion of fruit and vegetables, 76% of men and 80% of women usually got it right. Nearly four out of five women but only three out of five men (78% and 62%) knew that the recommended number of daily portions was five.

The report pointed out the clear link between unhealthy diet and poor health and premature death, which is costing the NHS more than £2bn. "A government consultation into issues concerning healthy eating (2004) highlighted the need for the population to have sufficient information and knowledge to make informed choices about their diet," it said.

"The subsequent government white paper 'Choosing a better diet: a food and health action plan', identified a number of priorities for action surrounding health and nutrition, and to contribute to a reduction in cardiovascular disease, cancer and obesity, through encouraging the population to adopt a healthy lifestyle."

Mark Davies, a GP and medical director of the NHS Information Centre, said: "It is important that people understand the health implications of the lifestyle choices they make. It is of concern that the ­messages of safe alcohol intake, ­appropriate exercise levels, and healthy eating do not seem to be getting through to all parts of the population. This is ­something the country needs to address if we are to avoid significant health ­problems in the near future."

The public health minister, Dawn ­Primarolo, said that more campaigns were on the way. "In the New Year we will launch our ambitious Change4Life movement. Change4Life will help families to move more, eat well and live longer.

"Thanks to the Know Your Limits campaign more people now know how many units are in their drinks. And the smokefree law is the single most important public health initiative for a generation. Because of the new smokefree law, thousands of lives will be saved and the health of everybody is being protected."