The BBC has apologised after a Mensa spokesman described anyone with an IQ of below 60 as a "carrot" live on air.
Peter Bainbridge made the comments while being interviewed on BBC Breakfast, sparking complaints from viewers.
A number of parents and carers called and emailed the learning disability charity Mencap saying they found Mr Bainbridge's comments "deeply offensive".
One viewer, an employee of Mencap, said she was "shocked" and "disgusted" by the comments.
Ciara Evans, who has a learning disability, urged Mr Bainbridge to "engage his brain before his mouth".
He was being asked about the effectiveness of IQ tests at judging intelligence when he made the remark, saying: "So most IQ tests will have Mr and Mrs Average scoring 100 and the higher you get, the brighter you are. And if your IQ is somewhere around 60 then you are probably a carrot."
After the interview with presenters Louise Minchin and Charlie Stayt, some of the complaints were read out on air.
The hosts then apologised at the end of the programme and read out a personal apology from Mr Bainbridge.
One of the complaints read out on air came from a Dr Sullivan who said: "As a clinical psychologist who has worked with many people who have an IQ below 60, I find these comments to be offensive and completely incorrect. Such comments perpetuate the stigma around an individual with learning difficulties.
Ms Evans, a campaigns assistant with Mencap said: "As a person with a learning disability, I am shocked that someone has described people like me as carrots.
"We can achieve a lot in life: I live independently, have a full-time job and I'm getting married next year."
She added: "I am disgusted that he made this comment and on behalf of all the people who have tweeted, rung and emailed Mencap to say how upset they are, I think Mensa should apologise and he should engage his brain before his mouth. It seems that having a high IQ doesn't make you a sensitive or caring human being."
Some viewers took to Twitter to complain about Mr Bainbridge's comments:
A BBC spokeswoman said: "A number of viewers contacted BBC Breakfast this morning, who were offended by comments made by a contributor during a live interview on the programme.
"Following the initial item we broadcast a selection of the complaints on-air a short time later in the programme, and both presenters apologised at the end of the programme and read out a personal apology from the contributor.
"Clearly we do not condone the comments that were made in any way and sincerely apologise for the offence caused."
According to Mencap, 1.5 million people in the UK have a learning disability.
Mensa was founded in England in 1946 by Roland Berrill, a barrister, and Dr Lance Ware, a scientist and lawyer, who wanted to form a society for people with a high IQ.
As well as Carol Vorderman, whose IQ is 154, and inventor Sir Clive Sinclair, Jimmy Savile was a member of the society.
Mensa said it will issue an apology through its website shortly.