Ross Smith, 27, Renuga Veeran, 26, and Glenn Warfe, 28, were struck down with the illness on Tuesday while taking part in training preparation in Derby.
The team arrived in the city on Monday to spend a week training at Etwall Leisure Centre before the start of the Olympic Games later this month, and are staying at a local hotel.
Michael Tancred, from the Australian Olympic Committee, said: "We hope they'll be back in training tomorrow. The public health authority is investigating the cause of the food poisoning.
"The players are improving, they've eaten this morning and have taken part in some light exercise."
He confirmed that two other members of the team, Leanne Choo and Victoria Na, were not affected.
A spokeswoman for South Derbyshire District Council, which is hosting the Olympic teams, said: "Our environmental health officers are investigating and we cannot yet say what is the nature of this illness."
Players from the Canadian badminton team are also training in Derbyshire ahead of the Olympics.
The two teams are due to take part in a special match at Etwall Leisure Centre on Saturday, where they will team up to compete with a GB All Stars team which will include Derbyshire Olympian Donna Kellogg, her former doubles partner Gail Emms and Nathan Robertson.