The most important individual risk factors for poor diet are ageing, ill health, eating disorders and socio-economic circumstances.  Many of these risk factors are described in the Inequalities section.

There is growing recognition that people do not make dietary choices based on the full costs and benefits of these decisions. 1  Decisions over what, when and where we eat and drink is governed by a complex mix of inter-related factors, including biological, psychological, social and economic influences. 2  At a basic level, we eat because we are hungry. However, our dietary behaviour is often not based on conscious decisions, but is the product of habit and automatic cues.

A European Commission briefing identified the following underpinnings of consumer dietary choices: 3

  • decisions are made on the basis of habit and positive experiences of brands
  • people make quick decisions and often don’t really think about the consequences (mental short cuts)
  • people find it harder to give things up and are more likely to try something new
  • food label reading is a low priority and people like to compare ‘like for like’
  • people choose products or brands which make a statement about their identity
  • people struggle with too much choice.

Much is also determined by the wider ‘food environment’, i.e. the availability and affordability of healthy food as well as social and peer influence. For more detail on these wider environmental determinants of dietary behaviour see ‘The food environment’ section of the Society and environment chapter of the JSNA. Other specific influences on individual food and drink choices include the following.

  • One study of people with a high Body Mass Index (BMI) found that taste is more of an influence than health considerations. 4Similarly, the taste of ‘unhealthy’ takeaway food is one of the primary reasons for regular purchases by young people, and this overrides any concerns about possible negative health effects. 5
  • Portion sizes. There is evidence that portion sizes of meals purchased out of the home have been increasing over the last 30 years, and that package sizes for snack items have got bigger. 6
  • Habitual behaviours are repeated (often automatically), commonly triggered by social and environmental cues (e.g. product placement or peer behaviour), and can be difficult to control or change. The cues to eat and drink are increasingly to consume unhealthy foods.7
  • Individual perceptions of diet. Underestimation of energy intake is a common phenomenon, especially among women, older people and people who are overweight. 8 9
  • Food and drink advertising. Advertising has a strong influence on the dietary behaviour of both children and adults (40% of all the food we buy is on offer, for example ‘buy one get one free’). 10 11
  • Mistrust of health messages. There is widespread mistrust of different healthy eating messages and advice, which has been fuelled by the emergence of social media that can contribute to the confusion of health messages.12
  • Dietary patterns and trends. Changing dietary trends can have a major influence on the food that people consume – some positive, others less so. For example, vegetarian (and to a lesser extent) vegan diets are now mainstream, and wheat or gluten free diets are increasingly common. In general, households in the UK are eating less meat, fruit, vegetables, potatoes and bread than they were five years ago.13  Some trends are complicated by an individual’s relationship with food and may be health harming, such as a recent phenomenon that has been labelled ‘orthorexia’ (which refers to extremely restrictive diets. 14)
  • Cultural influences. Cultural and religious influences also play a major role in the dietary behaviour of certain communities. For example, halal diets include food permissible or lawful in Islam, while kosher food conforms to the regulations of Jewish dietary law. 15 16

A recent study of three communities in east London (including residents of a housing estate in Hackney) helps to illustrate these various influencers at a local level. The researchers divided the population into four groups or ‘segments’, according to the wider influences on their health behaviours (including healthy eating).  A summary of the findings of this research is presented in Figure 3.  This study found significant variation in the dietary choices of each of these groups, with those in the ‘thriver’ and ‘fighter’ groups more likely to choose healthier foods when hungry (e.g. fruit and vegetables) and those in the ‘disengaged’ or ‘survivor’ groups more likely to choose less healthy options (e.g. takeaway food, crisps or cake).

Figure 3: Segmentation of children and adults – based on the Healthy Foundations Life Stages Mode (2010)

Describes the options available to groups titled, "Fighters", "Thrivers", "Survivors" and "Disengaged"
Figure 3: Segmentation of children and adults – based on the Healthy Foundations Life Stages Mode (2010)

Source: Adapted from Healthy London Partnership: Healthy Communities stage 1 research. 17


  1. European Commission , “Real World Breifing note 2. Food and Drink,” Policy Studies Institute, London, 2006.
  2. Foresight, “Tackling Obesities: Future Choices- Project Report,” Government Office for Science , London , 2007.
  3. European Commission , “Real World Breifing note 2. Food and Drink,” Policy Studies Institute, London, 2006.
  4. O. Petit, D. Merunka, J. Anton, B. Nazarian and C. Spence, “Health and pleasure in consumers dietary food choices: Individual differences in the brains’s value system,” PLoS ONE, vol. 11, no. 7, 2016.
  5. N. Stoll, K. Collet and D. Brown, “Healthy Fast Food Evaluation,” Shift, London, 2016.
  6. Public Health England, “Sugar Reduction: from evidence to action,” Crown, London, 2015.
  7. D. A. Cohen and S. H. Babey, “Contextual influences on eating behaviours: heuristic processing and dietary choices,” Obes Rev, vol. 13, no. 9, pp. 776-779, 2012.
  8. The Behavioural Insights Team, “Counting Calories,” Behavioural Insights LTD, London, 2016.
  9. Food Standards Agency, “Attitudes and behaviours towards healthy eating and food safety,” Policy Studies Institute, 2009.
  10. S. Livingston and E. Helsper, “Does advertising literacy mediate the effects of advertsing on children? A critical examination of two linked research article,” LSE, London, 2007.
  11. Public Health England, “Sugar Reduction: from evidence to action,” Crown, London, 2015.
  12. L. S. Suggs, C. McIntyre, W. Warburton, S. Henderson and P. Howitt, “Communicating health messages : a framework to increase the effectiveness of health communication globally,” World Innovation Summit for Health, 2015.
  13. DEFRA, “Family Food 2014,” ONS, 2014.
  14. A. L. Olea Lopez and L. Johnson, “Associations between restrained eating and the size and frequency of overall intake, meal, snack and drink occasions in the UK adult National Diet and Nutrition Survey,” PLoS ONE, vol. 26, no. 11, 2016.
  15. Halal Monitoring Committee UK, “Defintion of Halal,” [Online]. Available: [Accessed 10 October 2016].
  16. International Kosher Council , 2014. [Online]. Available: [Accessed 10 October 2016].
  17. Healthy London Partenership, “Healthy Communities Stage 1 report,” Uscreates, London , 2016.