Tummy bug Walliams struggles to eat
David Walliams has been struggling to hold down any food as the funnyman remained in the grip of a stomach bug which is hampering his mammoth Thames swim.
And his ongoing battle with illness was causing his trainer concern, with the TV star consuming a tiny proportion of the 8,000 calories he needs daily.
Little Britain star David had eaten only a piece of toast, a flat cola and some glucose tablets to keep his energy levels up on Thursday.
It is a far cry from the non-stop cake diet he talked about before setting off on the 140 mile swim from Gloucestershire to London.
The comedy actor, 40, was hit by the bug on Wednesday, causing vomiting, diarrhoea and high temperature.
The exhausted star said he was determined to battle on with his small reserve of energy. "I'm still feeling ill and getting cramps, so am not great. I can't face food really either so that's a worry," he said.
"But I can still put one arm over the other and that's what I need to do and keep doing."
The bacterial bug has meant David's pace during the fourth day of the BT Sport Relief Challenge has slowed markedly.
His plan to stick to the eight day schedule is now looking doubtful.
Trainer Greg Whyte said: "David is burning upwards of 8,000 calories a day but his stomach problems are meaning he can't get the fuel in him he needs. It's a vicious circle which means his pace is slowing - but he's ploughing on."