England is a nation of secret boozers, with more than a third of the population drinking unhealthy quantities of alcohol, new research suggests.
The finding released on Wednesday, which also uncovers high levels of binge drinking, is based on the discrepancy between alcohol sales and the amount people say they drink in surveys.
International studies show that self-reported alcohol consumption only accounts for between 40% and 60% of sales.
After taking this into account, an estimated 44% of men and 31% of women in England were found to be drinking more than the Royal College of Physicians' safety guidelines for weekly alcohol consumption.
The RCP recommends limits of 21 units of alcohol a week for men and 14 for women. A unit of alcohol is roughly equivalent to half a pint of ordinary strength beer, or nearly one small glass of wine.
Lead researcher Sadie Boniface, from University College London, said: "Currently we don't know who consumes almost half of all the alcohol sold in England. This study was conducted to show what alcohol consumption would look like when all of what is sold is accounted for, if everyone under-reported equally.
"The results are putative, but they show that this gap between what is seen in the surveys and sales potentially has enormous implications for public health in England."
The missing alcohol intake increases the prevalence of unhealthy weekly drinking by 15% in men and 11% in women.
Three-quarters of the population were said to be drinking more than the limits for daily consumption recommended by the Department of Health. These are set at four units a day for men and three for women.
After factoring in under-reporting, the study also suggests that around half of all English men and women can be classified as binge drinkers.
Binge drinking is defined by the Department of Health as consuming more than eight units of alcohol in a single session for men, and more than six units for women.
The adjustment pushes up levels of binge drinking most among women, those on high incomes, and people living in the south of England.
The research is published in the European Journal of Public Health.
Ms Boniface's team drew on self-reported data from two major surveys on alcohol consumption conducted in 2008.
The General Lifestyle Survey (GLF) recorded average weekly alcohol intake among 12,490 adults in England. Daily consumption was assessed by the Health Survey of England (HSE) which examined reported alcohol consumption of 9,608 adults on the heaviest drinking day of the previous week.
"What's needed now is a detailed understanding of whether some people under-report their consumption more than others: to what extent does this vary between men and women for example, by how much someone drinks, or by what types of drink they prefer," Ms Boniface added.
"Little is known on this at present, but this could reveal groups who under-estimate their alcohol consumption substantially, illuminating areas where targeted alcohol education initiatives should be developed."
Shadow public health minister Diane Abbott said: "This has got to be a wake-up call for the government and the country, because after more than two years of bitter internal rows, the government has got cold feet about its only proposed alcohol harm policy.
"More needs to be done to tackle problem drinking, which costs the country £21 billion - money we cannot afford.
"I'm absolutely clear that we need to see huge change in our hospitals and high streets - nothing short of a political and cultural earthquake.
"Labour support a minimum unit price but it won't work on its own, and the Government has so far resisted stronger action on prevention.
"Educating young people on the risks of alcohol has been removed from the curriculum and the Government voted against our proposals for stronger licensing powers for local councils to take action in their areas."
A Department of Health spokesman said: "We already know people underestimate what they drink and many drink too much. That's why we work to help people make healthier decisions, including the recent Change For Life campaign to help them track consumption and understand the impact on their health.
"We're also tackling excessive drinking through our proposed minimum unit price at 45p per unit, tougher licensing laws, more GP risk assessments, better access to specialist nurses and more specialised treatment."