"It means children with this problem are not growing, they are tired and they are not performing on all cylinders."
The report by the Royal Australasian College of Physicians estimated 14,000 New Zealand children needed the operation but were missing out.
Dr Mahadeven said parents often put the tiredness and eating problems down to other reasons and the bigger issue was missed.
Enlarged tonsils and associated sleep apnoea also caused eating problems because food couldn't easily pass inflamed tonsils.
And parents of children who snored often believed it was normal because other people in the family snored.
"Occasional snoring, say when a child has a bad cold, is acceptable," Dr Mahadeven said.
"But if a child is snoring often or when they seem otherwise healthy, I would advise they are checked."
The report also found one in three children who snored had obstructive sleep apnoea.
The implications of OSA were so wide-reaching that children on the waiting list at Starship Children's Hospital received 100 points - the same number as those needing cancer treatment.
Dr Mahadeven said tonsillectomies - where lumps of lymphoid tissue are removed from either side of the throat - had come "in and out of fashion" throughout the decades.
"In the 70s we took a lot out, now we don't do enough. We need to be doing the right amount and for the right reasons," he said.
Auckland mother Nikki Bodde spent countless nights by her son Joshua's bed monitoring his breathing until he had surgery last year.
"He was snoring, gurgling and gasping for air," she said. "We were told it was because he had a cold and a blocked nose."
Joshua was finally diagnosed with enlarged tonsils and adenoids after being misdiagnosed by his doctor as having pneumonia.
Joshua displayed all of the classic signs of OSA, including weight loss and extreme tiredness.
She said these days Joshua, now 3, was a brilliant child who had put on weight, was inquisitive and reaching all the children's milestones.
"He is running circles around me now, whereas before he was in his own little world."
SHE'S FULL OF ENERGY AFTER OP
Little Eilish Johns is a different girl from the one who had her tonsils and adenoids out a month ago.
Happy, energetic and strong are words mum Hayley uses to describe her 4-year-old daughter now she has fully recovered from surgery.
"The change we have seen in her is remarkable," Hayley Johns said.
"She was lethargic and had no stamina. She would chew food but would spit it out because she couldn't swallow it." Now she is eating steak, lamb and beef strognanoff.
"Basically, we open the fridge and she will eat," Hayley said.
Eilish was typically on antibiotics for 10 days at a time, with a week off in between. Last winter she had eight bouts of tonsillitis and was plagued with headaches and fever.
She had enlarged tonsils but was affected mainly by recurring tonsillitis, which had her on antibiotics more often than she was off them.
She would fall asleep on the way to pick up her older brother and sister from school.
Hayley and husband Malcolm said they wanted to get their daughter well before she started school.
"She wouldn't have had the energy to keep up with other kids otherwise," Hayley said. "She has even learned to ride her two-wheeler because she has the energy to do it. She is a completely different child."
