The report calls on food manufacturers and retailers to work with the government's food watchdog to reduce salt, sugar and fat in foods aimed at children and remove snacks and sweets from supermarket checkouts.
Commissioned by the children's charity NCH, the 'Going Hungry' report also underlined that it costs significantly more to eat healthily, with a large basket of 'healthy' food costing just over £25. Its unhealthy equivalent is just over £21, almost a fifth cheaper and it is getting more expensive to eat healthily every year.
Since 1989 the cost of the healthy shopping basket has increased by 50 per cent while the unhealthy option has risen by just a third, said the charity.
This cost is prohibiting many low income families from choosing healthy options and as a result, many children have a nutritionally poor diet, found the survey.
Almost 30 per cent never eat green vegetables or salad, while one in ten never eat fruit and 43 per cent eat crisps most days.
Caroline Abrahams, NCH's director of Public Policy, said: "It is right to be concerned about rising levels of childhood obesity - but NCH's new report shows that it's unfair to place all the blame on parents and children. The comparatively high cost of healthy food and sophisticated marketing used to encourage children to eat junk food are also significant factors."
"Going Hungry shows that the government needs to do much, much more if it is to put healthy food within the reach of children. Action is needed in schools, in the community and within the food industry. Most of all the government must make healthy food affordable to low-income families. Otherwise, drives to end child poverty and improve the nation's health are set to fail."