Da Vinci's Last Supper was painted in the 15th Century
The food portions depicted in paintings of the Last Supper have grown larger - in line with our own super-sizing of meals, say obesity experts.
The Cornell University team studied 52 of the most famous paintings of the Biblical scene over the millennium and scrutinised the size of the feast.
They found the main courses, bread and plates put before Jesus and his disciples have progressively grown by up to two-thirds.
This, they say, is art imitating life.
Professor Brian Wansink, who, with his brother Craig, led the research, published in the International Journal of Obesity, said: "The last thousand years have witnessed dramatic increases in the production, availability, safety, abundance and affordability of food.
"We think that as art imitates life, these changes have been reflected in paintings of history's most famous dinner."
He says the finding suggests that the phenomenon of serving bigger portions on larger plates has occurred gradually over the millennium.
His team used computer-aided design technology to scan and calculate the relative measurements of items in the paintings, regardless of their orientation.
These included works by El Greco, Leonardo Da Vinci, Lucas Cranach the Elder and Rubens.
Based on the assumption that the width of an average loaf of bread from the time should be twice that of the average disciple's head, the researchers plotted the size of the Passover evening dishes.
The main meals grew 69% and plate size 66% between the oldest (carried out in 1000AD) and most recent (1700s) paintings. Bread size grew by about 23%.
The sharpest increases were seen in paintings completed after 1500 and up to 1900AD.
Craig Wansink, who is a professor of religious studies, says the changes in portion sizes is probably a reflection of culture rather than theology.
"There is no religious reason why the meals got bigger. It may be that meals really did grow, or that people just became more interested in food."
Charlene Shoneye, an obesity dietician for the charity Weight Concern, said: "I'm really not surprised by these findings because the size of our plates and food portions has increased.
"Twenty years ago, for example, most crisps used to come in packs that were 20g. Now they are 30g, 50g or even 60g, and we are still eating the whole pack.
"This super-sizing has changed our perception of normal."
But she said it was not too late to reverse the trend and that individuals, society and the food industry should look to smaller portions.
"Part of the problem is the type of food that has increased in size. Portions of fruit, veg and salad have not grown. They should make up about a third of your plate, with the remaining two-thirds left for protein and starchy foods."