The School Food Trust has responded to new research, published in The Lancet, predicting that 26 million people in the UK could be clinically obese by 2030.
The charity's chairman, Rob Rees, said: "There are simple things which can make a huge difference here. We have to start early - support nurseries, children's centres and other providers of childcare to offer balanced menus, encouraging children to try lots of different foods and to eat together. We have to help families with young children to develop the skills they need to cook healthy meals, from scratch, at home.
"We also need to encourage more children to choose healthy school meals - which on average are much healthier than a typical packed lunch - and keep up the great work in schools to make nutritious menus tasty, varied and fun.
"Finally, we have to make sure that all children have the chance to learn to cook. We know from our work in thousands of schools all over the country that cooking skills improve diets. It's a life skill which will help children to grow into healthier adults."
Terry Jones, Food and Drink Federation's director of communications added: "The Lancet fails to recognise the lengths to which the UK food and drink industry has gone to help improve the health of the nation, particularly in relation to rising obesity levels."
"Earlier this year we were pleased to have been a founding signatory of the Government's Public Health Responsibility Deal – demonstrating our commitment to a multi-stakeholder and coordinated approach to improving public health.
"We bring with us our track record of achievement in key areas such as the reformulation of products – an area where the UK is now widely recognised as leading the world, the provision of clear consumer information and our drive to support our own workforce to make healthier choices.
"On product reformulation, the UK has been ahead of the game for a long time in reducing salt, energy and fat in their products. Achievements so far include a 9% reduction in the amount of salt and fat consumed by households since 2006 (source: Kantar World Panel), and via the Responsibility Deal, our members have committed to reduce levels even further where technologically possible, safe and acceptable to consumers.
"We recognise the significant threat that obesity poses to society and have taken a proactive part in improving health. Food companies are well aware of the complex diet, lifestyle and health challenges facing society and understand the high expectations that policy makers, regulators and campaigners have of the entire food industry.
"Though the Responsibility Deal initiative is still in its infancy, we firmly believe that as the Organisation for Economic Co-operation and Development made clear last year 'co-operation between government and industry is the single most critical link in a multi stakeholder approach."