"Maradona travelled to Italy to check into a spa he knows where he will do a diet to lose five kilos," his personal doctor Alfredo Cahe was quoted as saying in Buenos Aires.
"He is fine, a lot better than many people think, he is serene," Cahe told the Argentine news agency Telam.
Italian media said Maradona, whose team are in danger of missing out on next year's World Cup after recent defeats by Brazil and Paraguay, had checked into The Henri Chenot clinic in Merano. The clinic could not be reached for comment.
Maradona, 48, has fought a long battle with weight problems and Italian media reports noted he had used Chenot's services to get fit while playing for Napoli 20 years ago.
Wednesday's 1-0 loss to Paraguay left Argentina fifth in the 10-nation South American group, which would mean a playoff with CONCACAF's fourth-placed nation to reach the World Cup finals.
The twice World Cup winners still have a chance to sneak into the top four and secure automatic qualification but could also slip out of the picture altogether with two games left.
Maradona, a surprise appointment as national coach in November, could also use his trip to Europe to check out a number of Argentine players for October's qualifying games at home to Peru and away to Uruguay.
Argentina have a warm-up match at home to Ghana in Cordoba on September 30.
