A seven year-old boy has to drink almost a litre of olive oil a week to keep his brain working.
Schoolboy Adam Watson is one of just 300 people in the world who suffer from an extremely rare genetic condition which means his brain cannot receive proper nourishment from normal food.
So he has to drink a glass of oil with every meal, otherwise he might collapse. In fact, he drinks so much that his hands often turn orange.
Now his parents, Stefanie, 35, and Billy, 40, from Arbroath, Scotland, are trying to raise £5,000 to travel with Adam and their six-year-old daughter Evan to a special conference on the condition being held in Indianapolis, US, in July.
They hope that a treatment will be developed that will one day lead to Adam being able to have a relatively normal life.
Shortly after he was born, Adam was diagnosed with cerebral palsy. But doctors later discovered that he was in fact suffering from an incurable illness known as Glut1 deficiency syndrome.
Instead of being fuelled by glucose as is normally the case, Adam's brain relies on energy produced when fat is metabolised to allow him to think, move and socialise like other children.
The only treatment is a high-fat diet which minimises his intake of proteins and carbohydrates.
This means Adam can never have junk food like pizza, ice-cream or chocolate because, although high in fat, their carbohydrate content is also too great.
His meals usually consist of just a few slices of meat and a block of cheese - and the olive oil is one of the only ways for Adam to get the pure fat his brain requires.
Stefanie told the Mirror: "He is absolutely brilliant. He doesn't even flinch when we make him drink the oil.
"He drinks it with every meal out of a small cup, but always uses a straw.
"We give him the oil because it's so rich in vitamins and omegas - sometimes it makes his hands turn orange!"