Tom Halton was shocked when he was called overweight after being examined in a national scheme which measured children's body mass index.
The 11-year-old refused to eat dinner after the NHS letter was received. Now the department of health has issued a letter of apology.
His mother Tracey Halton said that her son again weighed himself at home after receiving the letter from Barnsley PCT, "But his weight was more than they weighed him at school, so that made him anxious straight away," she added.
Tom's father Dan Halton added that the letter was offensive, "Not only does it say you are fat, but there is a possibility you are going to get cancer, type 2 diabetes and heart disease - and that also reflects on me as a parent."
The Department of Health said in its apology letter that it was sorry that the letter offended him and added that it did not reflect on his parenting skills in any way.