London - Health advice to drink eight glasses of water a day is over the top and does not help with weight loss, says a leading nutritionist.
Fruit, vegetables and juices should have a major role in providing the fluids we need, he added.
Spero Tsindos, an academic and public health expert, also argued that the push to encourage people to drink more water was driven by vested interests.
Tsindos said sales of bottled water had risen in tandem with guidance from bodies such as the National Health Service telling individuals to drink large volumes.
He said the NHS had reinforced the notion that two litres or eight glasses of water a day was good for health “without any substantial evidence to support it”. If people drink two litres of water in a hurry to make up their daily allowance it will not hydrate the cells that need it – but simply dilute the urine, he pointed out.
Health and dietary authorities generally recommend two litres a day of fluid for optimal health, but “this has been misinterpreted to mean two litres of water specifically and it has driven a steady growth in the use of bottled water”.
Tsindos says in an editorial in the Australian and New Zealand Journal of Public Health: “Thirty years ago you didn’t see a plastic water bottle anywhere, now they appear as fashion accessories.
“As tokens of instant gratification and symbolism, the very bottle itself is seen as cool and hip.”
While water was now regarded as a slimming aid, tea and coffee were being wrongly shunned as potentially leading to dehydration. Tsindos, of the department of dietetics and human nutrition at La Trobe University, in Melbourne, added: “Drinking large amounts of water does not alone cause weight loss. A low-calorie diet is also required.
“Research has also revealed that water in food eaten has a greater benefit in weight reduction than avoiding foods altogether. We should be telling people that beverages like tea and coffee contribute to a person’s fluid needs and, despite their caffeine content, do not lead to dehydration.”
He said food, juices, fruit and vegetables also contribute to overall intake. “We need to maintain fluid balance and should drink water, but also consider fluid in unprocessed fruits and vegetables and juices.”
Independent dietician Dr Carrie Ruxton said individuals tend not to drink enough. She added: “Drinking water is useful for weight loss, as part of a strategy of eating less and being more active. Research shows a glass of water before meals reduces appetite.
“I agree that caffeine is wrongly thought to be dehydrating, people can drink up to eight cups of tea or four cups of coffee a day and be reassured that it’s healthy.”
A spokesman for British Bottled Water Producers said the World Health Organisation and the British Dietetic Association recommends the average 60kg (9.5stone) adult should drink 1.5 to 2 litres (3.5 pints) of fluid a day.
She said: ‘”t a time when many people are overweight and there is a tendency to drink too much alcohol, it cannot be disputed that water is the safest, simplest route to calorie-free, toxin-free, safe and healthy hydration.” - Daily Mail