According to a survey by consumer information company Claritas, 49% of Iceland shoppers admit they "buy what the kids want".
The research forms part of the 2002 National Shoppers Survey, which had more than 900,000 responses, and shows which shoppers give in to the demands of pester power while shopping for groceries.
Second on the list is Kwik Save with 45% of shoppers saying they buy what their kids want. This is followed by Asda at 44% and Morrisons at 42%. Waitrose shoppers are at the bottom of the list, with only 24% being influenced by pester power.
Claritas analyst Jackie Vaughan believes the reason is due to Iceland stores stocking less fresh produce and more processed foods, which appeal to children. "Iceland parents may not be as fanatical about healthy eating as other parents, hence may be more likely to give in to their children's requests, if they fit within their given budget", says Vaughan.
Keith Phillips, a consultant at Claritas, says the figures highlight the strength of impulse purchasing behaviour and the impact of store layout and product positioning. He believes some supermarkets actively target children, but he also admits social and demographic factors are important and need further investigation.
But pester power is concerning some bodies. For instance the Food Commission's Parents Jury gives out a pester power award for manipulative advertising or marketing techniques', which last year went to McDonald's for its children's Happy Meal.
However Dave Lawrence, planning director at promotions agency Logistix Kids, believes this concern is misplaced. "Pester power has become an over-simplistic shorthand for kids' marketing laced with emotionally charged negative perceptions of screaming kids and overwrought parents," says Lawrence.
He says pester power only happens in a minority of purchases and is only prevalent among children aged under three. Lawrence explains: "Due to their cognitive development, toddlers of this age have very limited communication skills and often have to resort to tantrums to get what they want, be it at the playground or the supermarket."
He also believes it is difficult to generalise pester power as there are many factors influencing the child-parent relationship, including the mum typology', which ranges from the traditional controller to the laissez-faire mum, and the product category that is being shopped. Lawrence says the level of parental acceptance of kids' involvement, and interest from kids differs dramatically between categories.
But a child's influence on shopping decisions is not necessarily a bad thing. As children get older, Lawrence says they are able to negotiate with their parents so their influence in the purchase of products becomes more subtle and complex.
He believes parents should actually encourage their children to get involved with shopping decisions as part of a family democracy', as allowing kids partial ownership of the selection process is more likely to ensure their support at the dinner table.
The key, says Lawrence, is finding a win-win' scenario for both mum and child "Where the kids are happy because they get a brand they like, and mum feels good as a responsible mum able to please her kids".
Yet he does believe manufacturers must address mum's concerns on nutrition and have clearer labelling. Those that focus their marketing strategies purely on harnessing pester power will ultimately lose integrity, says Lawrence.