My grandfather would have loved this story... He would keep a fast food cup in his car just so he could go in and get "free" refills...
It's a conundrum that’s long challenged gluttons and hard-up students.
But now a scientist claims he has worked out how to truly make the most of a buffet bar – by piling food into a 3ft-high tower.
Unfortunately, while it allows you to eat vast quantities, the results don’t exactly look appetising.
Shen Hongrui, a Chinese engineer, advises hungry diners to build strong ‘walls’ with cucumber and carrots, creating a tall container on their plate to fill with their favourite foods.
He devised the set of instructions to get around the ‘one bowl, one visit’ rule at the salad bar in his local Pizza Hut in Beijing.
Next, would-be gluttons must create a layer of carrot sticks radiating from the centre to act as a scaffold.
Banned: Pizza Huts in China have put a stop to the craze by removing all the salad bars in restaurants
Then they should use slices of cucumber or blocks of fruit as bricks to build the tower’s ‘walls’.
Finally, fill the tower with the food you are most keen on eating. All you need after that is a steady hand to carry your heaving platter back to the table.
The art of piling food high on one’s plate has become known as ‘salad bar hacking’, inspiring websites with galleries devoted to towering piles of food.
But Mr Hongrui’s method ended up backfiring – it became so popular that Pizza Hut scrapped all its salad bars in China.
The towering piles of cucumber – too much for a single person to eat – seem likely to end up in the bin and are likely to horrify campaigners against food waste.
Last year, 60 per cent of all food thrown away could have been eaten, according to a recent study – around 7.2million tons a year. The figure is down around 13 per cent on the previous year – possibly because of the economic downturn.
Other scientists have also been fascinated by salad bars.
Brian Wansink and colleagues at the Food and Brand Laboratory at Cornell University noticed that people with a high body mass index (BMI) – a measure of obesity - sit on average 16ft closer to a buffet than those with an average BMI.
They also found that 71 per cent of overweight people sit facing the food, compared to around 26 per cent of people of average weight.