Children growing up in the most deprived areas of the UK are over twice as likely to be obese as children growing up in the least deprived areas. Obesity and associated malnutrition in childhood can have significant long-term impacts on physical and psychological health, and on children’s long-term social and economic outcomes. In this article, Professor Dame Rachel Griffith analyses what drives poor nutrition and assesses policy efficacy around this issue.

• The costs of child obesity are likely to be significant and long lasting. The costs of adult obesity are estimated to be substantial, at around 3% of GDP.
• The National Food Strategy made series of policy recommendations to tackle obesity rates and poor nutrition.
• University of Manchester research with The Institute for Fiscal Studies (IFS) studied drivers of poor nutrition and evaluated the impacts of several policies.

Deprivation and obesity – impacts on children

Obesity rates in the UK, and around the world, are rising. These are rising faster amongst people living in more deprived areas. Of particular concern is the increase in obesity amongst children growing up in deprivation. 30% of children in year 6 in 2022/23 living up in the most deprived areas of the UK were obese, compared to 13% of children living in the least deprived areas.

This gap has doubled over the last 20 years. Obesity and associated malnutrition in childhood can have significant long-term impacts on physical and psychological health. They can result in potential consequences for children’s long-term social and economic outcomes.

Poor nutrition – research into the causes

Understanding the drivers of rising obesity and poor nutrition can help to design better and more effective policies.

Ensuring that all children, including those from disadvantaged backgrounds, are well nourished is a cornerstone of the provision of equality of opportunity likely to have significant long-term payoffs in terms of preventing health and social problems and increasing productivity.

My research with colleagues at The Institute for Fiscal Studies (IFS) analysed the drivers of poor nutrition, and evaluated the impacts of several policies. This work investigated the importance of household income levels, the relative prices of healthy versus unhealthy foods, how people spend their time (particularly on home cooking), and the choice environment in which people make decisions over the foods to buy and eat (including the effects of advertising and self-control).

Public policy – weighing the costs

The economic rationale for government policy in this area is to reduce the social costs that obesity and poor nutrition generate. For example, costs arising from long term social and health problems and reduced economic productivity.

Some policies might reduce these social costs in ways that do not generate any additional costs, for example by correcting a market failure. An example of this is what taxes on sugary drinks aim to do – the idea being that excess consumption of sugary drinks lead to increased social costs, and by increasing the price, policy can reduce consumption, and so reduce these social costs. However, most policies increase economic costs. A well-targeted policy will reduce social costs by more than it increases economic costs. A policy that is poorly- targeted might raise economic costs by more than it reduces social costs, at least for some people. For example, if a tax raises prices but people do not respond to the increased prices by reducing consumption, then this will lead to increased economic costs (through higher prices) but no reduction in social costs.

In order to understand how well targeted a policy is, it is important to understand what the economic costs are, and who is bearing them, as well as what are the reductions in social costs and who is most affected. Obtaining empirical estimates that are useful to policy makers has been a focus of my research. This work has shown that:

• Targeted subsidies like Healthy Start Vouchers increase the nutrient composition of households’ shopping baskets.
• Taxes on sugary drinks, introduced in a large number of jurisdictions, have been effective at reducing consumption, especially at reducing sugar consumption of young people.
• Advertising restrictions would be likely to encourage more nutritious diets, although their impact may be muted by firms’ strategic behaviours.

The National Food Strategy – and further steps

Government policies can help people to make better choices and reduce long-term social costs. But care needs to be taken in designing these policies to minimise unintended consequences that lead to higher economic costs.

Fortunately, much thinking has already been done about what policies are most effective, and how they work together. The government commissioned a wide-ranging independent review, The National Food Strategy, that reported in 2021 on a range of policy recommendations intended to help the most disadvantaged families eat well and protect food standards. Policy recommendations included the introduction of taxes on the most unhealthy foods, advertising restrictions, increased generosity of targeted subsidies (such as Health Start Vouchers and Free School Meals), and a number of other related policies.

Targeted welfare such as Child Credit, Healthy Start Vouchers, and Free School Meals, can help parents who are struggling to make appropriate spending choices.  The decision over which policy to expand and how to expand them depends on a number of issues.

One possibility is to expand eligibility for food voucher schemes or Free School Meals to a wider set of families, by increasing the earnings level below which families are eligible. This would make a higher fraction of low-income families eligible, although it would not increase the amount available for the very poorest families who already are eligible.

Alternatively, the government could increase the value of the benefit per voucher – for example, making Healthy Start vouchers available to all eligible families, not just those with a child under one.

Government could legislate for free school meals to be provided at different times of the day or year. For example, providing healthy free school breakfasts in addition to lunches could boost concentration among children who may not eat breakfast at home prior to the school day.

Implementation of strategy policies

My research supports the recommendations made within the National Food Strategy, which focus on policies that target the very poorest families. When implementing these policies it is important that careful attention is paid to the details of how they are designed, to ensure that they target the right groups, and the economic and social costs and benefits are appropriately weighed up, as exemplified in the discussion of food vouchers and free school meals above. For free school meals for example schools could be paid more to provide lunches – although this would only benefit children if it led to schools providing more nutritious meals.

The National Food Strategy also makes the case for broader taxes on all sugar (rather than only in drinks), which is supported by my research. Extending tax on sugary drinks to a wider range of sugary products would be effective, particularly if the taxes encourage firms to reformulate their products to reduce the sugar intensity. The way these taxes are designed can have important implications. For example, taxes increasing the prices of sugary drinks may reduce consumption, but these taxes may also change firms’ other strategic choices, such as advertising – which can in turn shape demand.

Policymakers in this area must also recognise that if poverty is a driver of obesity then it is  important to prioritise the wide range of labour market policies that have the potential to directly lift people out of deprivation.