Children can be prone to ear infections
A history of severe ear infections or tonsil trouble may increase the chances of being obese later in life, according to scientists.
About a third of children get recurrent otitis media and research presented at a US conference suggests a link.
Infections may affect food choices by damaging nerves involved in taste, the researchers said.
However, a number of UK experts raised doubts about the findings, with one saying a link was "extremely unlikely".
Five separate studies aired at the American Psychological Association's conference hinted at an association between either ear infection or tonsil removal surgery and obesity.
In the first, more than 6,000 adults were quizzed about their history of ear infections and the results suggested that those with a moderate to severe history were 62% more likely to be obese.
Dr Linda Bartoshuk, who led the study at the University of Florida College of Dentistry, said that the finding was of "considerable" public health interest.
Another research project found that women who had impaired taste functioning were more likely to prefer sweet and high fat foods and more likely to be overweight.
The study authors suggested that nerve damage caused by severe infections could be to blame for this.
Dr Kathleen Daly, from the University of Minnesota Twin-Cities, presented research which suggested that babies treated with grommets for recurrent ear infections were likely to increase in terms of "body mass index" (BMI).
She said: "Obesity has doubled over the past 20 years among pre-school children.
"The more data we collect on what contributes to this major public health problem, the greater likelihood that we can help prevent it."
Having tonsils removed can be a sign of recurrent infection problems in the ear, nose and throat, and a survey of almost 14,000 people found that those who had had tonsils removed were 40% more likely to be overweight as adults.
However, UK experts raised doubts about the strength of the findings.
Paediatric ear, nose and throat surgeon Ray Clarke, from Alder Hey Children's Hospital in Liverpool, said it was well known that severe ear infections, and operations, could affect taste.
However, he said there was no other evidence that this could play a role in developing obesity.
He said: "There may well be some other common factor in obesity.
"In terms of tonsillectomies, these are frequently given to children with breathing problems such as sleep apnoea, which is certainly linked to being overweight in adults, and may be linked to weight in children."
Tam Fry, from the National Obesity Forum, said: "The potential link as reported leaves us somewhat agog.
"It is possible for there to be a link between otitis externa - a different form of ear infection - and obesity, because of the connection between obesity and type II diabetes, which can contribute to this condition."
Professor Mark Haggard, from the charity Deafness Research UK, said while there was a small chance that there might be an underlying genetic predisposition to both severe ear infections and obesity, the associations found here should not be overplayed.
"A connection is not impossible, but to be frank, is extremely unlikely," he said.