GLASWEGIANS in 1405 had a better diet than the citizens of 2005, eating their "five-a-day" 600 years ahead of its time.
Even their light beer was healthier than sugar-laden fizzy concoctions that are today's favourite, according to new archaeological evidence.
It reveals a diet of porridge and small amounts of pork and fish made medieval mealtime more nutritious than a visit to the chippy, the pizza parlour or the ubiquitous American fast food joints.
And an absence of sugar in the diet meant medieval Glaswegians had better teeth. In addition, they could not smoke, a major cause of diseases that killed 119 out of every 100,000 men in the city last year.
Experts agreed yesterday we could learn from our predecessors' eating habits as revealed by the council's new history and archaeology strategy.
Glasgow is developing a mapped medieval trail from Glasgow Cathedral to the Clyde, the medieval hub of the city.
By analysing cesspit material, archaeologists discovered medieval citizens ate a healthy diet of fruit, vegetables, cereals and fish. It is a long way in time and culture from modern Glasgow, where obesity is so commonplace because of a junk food diet of pizza, burgers and fish suppers that the Scottish Executive is considering opening an NHS-funded stomach-stapling clinic in the city.
Professor Stephen Driscoll of Glasgow University's archaeology department, said: "Around 100 bodies examined showed good health and the teeth were worn rather than decayed.
"The diet was healthier than today, with porridge, a little meat, fish, milk, cottage cheese and vegetables and fruits."
At one excavation, in Bell Street, cesspit material revealed large quantities of seeds and fish remains.
Councillor Catherine McMaster, on the working group for the medieval project, said: "It seems they were into 'five-a-day', 600 years before the rest of us. We modern Glaswegians could learn from it.
"We hope to reveal more of the city's rich tapestry of history by the medieval trail, and it is ironic that it is already revealing that they probably ate better then."
The "Glesca diet" is notoriously unhealthy, provoking the joke that whole generations were brought up on "chips and lemonade".
In some areas, 80 per cent of children develop tooth decay by the age of five because of a high consumption of fizzy drinks.
Recent research also showed that 63 per cent of schoolchildren in some areas were "less healthy eaters".
Dr Frankie Phillips, of the British Dietetics Association, said: "There wouldn't have been too many obese people in medieval times.
"We could certainly learn from some aspects of the diet that was uncovered."