One in three mums dread their children going to friends' houses for tea - because they know they'll be fed junk food and sweets.
Researchers found millions of mums worry that allowing their child to eat with a classmate or playgroup pal means they will miss out on healthy food and instead come home having been served up fatty, fast or frozen food, fizzy drinks, cake and ice cream.
As many as one in three mums have experienced their children arriving home feeling sick from the sheer amount of junk they consumed at the friend's house, the report found.
It also emerged as many as one in five parents has gone so far as to stop their children seeing certain friends outside of school to avoid landing invites to their house for tea.
Lorraine Miller, 29 from Coventry, who has three children, Eve, 5, Jake, 4 and George 1, says the older children regularly return from friends' houses hyper.
''My older two kids often come back from friend's homes or parties feeling sick or overly excited after overdoing it with crisps, sweets or biscuits. They both eat very healthily at home so often aren't used to it - there have been numerous times where they have come home and said they don't feel well or been sick.
''Some parents seem to cook more convenience food and give more sweets and treats than I would and it does make me think twice about letting them go around to other people's houses. But I would never say anything to the other mums. I don't think it would be taken the right way."
A spokeswoman for Kellogg's who commissioned the research in to the attitudes of 2,000 parents to mark the launch of their new range of Mini Max cereal, said: 'It's the nightmare of many parent - a loss of control over their kids.
''Now it seems British parents are quite literally sick with fear about losing grip on their kid's diets when they're not around.
"One of the big things parents say to us they worry about is the portions their children are given; sure a small bowl of ice cream is fine but a massive portion is another question.
"What our study does show is that the majority of parents said they make sure their children have a good breakfast before they leave the house because they are worried about what they will eat for the rest of the day."
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