There is confusion over portion sizes
People know a healthy lifestyle is important, but most are still baffled by guidelines on fruit, exercise and alcohol, a report shows.
Most adults knew they should eat five portions of fruit or veg a day, but few knew what constituted a portion, the Health Survey for England found.
Over two thirds did not know or under-estimated how much exercise to do.
And less than a third of adults knew the maximum amount of alcohol they should be drinking each day.
Only 14% of men knew that four units was the recommended daily maximum for a man and 6% of women knew that three units was the recommended daily maximum for a woman.
Overall, 42% of men and 31% of women had drunk more than the recommended maximum on at least one day in the last week.
Despite the confusion, the figures published from the annual survey, which monitors the health of the nation, suggest people are leading healthier lifestyles by eating more fruit and veg and doing more exercise.
WHICH FRUIT OR VEG PORTION HAS THE RECOMMENDED 80G?
2 cherry tomatoes - NO (less)
1 apple - YES
1 melon - NO (more)
4 grapes - NO (less)
1 jacket potato - NO (potatoes do not count)
2 tablespoons of carrots - NO (less)
Overall, 27% of men and 31% of women met the recommended guidelines of eating five or more portions of fruit and vegetables per day.
But only 14% of men and 11% of women knew what constituted a portion - 80g.
From a list of varying portion sizes of fruit and vegetables - two tablespoons of carrots; two cherry tomatoes; one apple; one melon; one jacket potato; four grapes - few identified the apple as the only correct one.
Yet obesity is still on the increase in adults - 24% of men and women in 2007 were obese up from 13% of men and 16% of women in 1993.
In children, however, obesity rates may be beginning to level out.
The survey of nearly 7,000 adults and over 7,500 children also looked at the impact of the recent smoke-free legislation introduced in July 2007.
It found no evidence that fewer people smoked as a result of the ban.
Exercise: Adults should do 30 mins of moderate or greater intensity activity on at least five days a week
Alcohol: Daily intake should not regularly exceed three to four units for men and two to three units for women
Fruit and veg: Eat at least five 80g portions of a variety of fruit and vegetables per day. Rice, pasta and potatoes do not count. Fruit juice, pulses and dried fruit count as one portion, regardless of how much is consumed in a day
However, cotinine levels in people's saliva - an indicator of recent nicotine exposure - showed that, since the introduction of the ban, smokers may be smoking less.
Medical director of The NHS Information Centre Dr Mark Davies said: "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."
Betty McBride of the British Heart Foundation said: "It's really worrying that people aren't clear how much exercise you need for a healthy heart."
Alcohol Concern said drinks manufacturers should be forced to put labels on bottles and cans of alcoholic drinks showing the unit content and safe limits.
Health Minister Dawn Primarolo said: "It's good to see that more people are taking steps to live more healthily.
"But too many people are overweight. In the new year we will launch our ambitious Change4Life movement. Change4Life will help families to move more, eat well and live longer."
Shadow Health Secretary Andrew Lansley said: "Labour's neglect over issues like obesity and alcohol abuse will leave a terrible legacy for the next Government to try and fix. We urgently need action now to tackle Britain's ticking obesity time-bomb."
Liberal Democrat health spokesman, Norman Lamb, said: "Childhood obesity is rocketing and it is horrifying that one in three children are overweight or obese by the time they leave primary school. The time for effective action is long overdue."