Key Points
Health inequalities are unfair and avoidable differences in health across a population, and between different groups within society. Justice, equality, and equity are related but distinct concepts in this area.
Greater societal inequality (the difference between the richest and poorest) is consistently associated with poorer health and social outcomes: including child mortality, obesity, and overall life expectancy.
Lower socio-economic status (SES) is associated with consistently negative and mutually exacerbating impacts across the six pillars of Lifestyle Medicine.
Strategies to improve lifestyle-related health inequality may work at multiple levels, including individual behaviours; social and community networks; socio-economic, cultural, and environmental conditions; and living and working conditions.
Lifestyle Medicine is predominantly focused on supporting an individual, most often in a clinical encounter, but must acknowledge the need for multilevel action to achieve the greatest and most equitable benefits.
6.1 Introduction
Inequalities are a matter of life and death, of health and sickness, of well-being and misery. The fact that today, people from different socioeconomic groups experience avoidable differences in health, well-being and length of life, is, quite simply, unfair and unacceptable.
In the 2010 report, ‘Fair Society Healthy Lives’, Sir Michael Marmot highlighted the impact of societal inequality on health in the United Kingdom, where socio-demographic background directly impacts an individual’s life chances and state of health. In this chapter, we will explore this link, with a particular focus on how this relates to the pillars of Lifestyle Medicine. We will explore the opportunities that Lifestyle Medicine has to address such challenges.
6.2 Terminology
The terms ‘health inequalities’ and ‘health disparities’ are often used interchangeably with ‘health inequities’. However, they have different technical meanings which we will explore particularly in the context of social justice.
6.2.1 Equality and Health Inequalities
Equality implies that every person is treated the same, regardless of their level of need, where need can be defined as ‘the capacity to benefit’ [Reference Bradshaw and Mclachlan2]. Equality describes equal status, access, or provision. It does not seek to address the differing levels of need. So, when equal help is given to all, those with a higher level of need are likely to remain relatively worse off. In terms of health outcomes, the term health inequalities describes variation in health needs or outcomes. However, in practice, the term has become synonymous with ideas of unfair and avoidable differences in health.
6.2.2 Equity and Health Inequity
Equity recognises different circumstances. An equitable approach results in people receiving the level of support they need, according to their specific situation (Figure 6.1). Health inequity is therefore a specific type of health inequality that actively implies an unjust difference in health. Most experts would argue that such inequities are largely preventable. For example, social group differences in health such as higher COVID-19 mortality among minoritised ethnic groups could be described as health inequity. Conversely, most health differences based on age (e.g. that people in their 20s tend to enjoy better health than those in their 80s) are unlikely to be described as inequitable.
Another way to consider these concepts is by contrasting equality of opportunity with equality of outcome. Those on the centre right of politics may tend towards the former, whilst those on the centre left of politics may tend towards the latter. As a policy objective, equality of outcome might be described as an equity-driven approach.
More often, equality, inequality, equity, and inequity are used interchangeably outside of policy circles. Over recent years health disparity has also entered the lexicon in an attempt to steer away from implications of injustice. A more commonly used term in health services – and which is not as value laden – is variation. This in turn may be qualified as warranted or unwarranted, explained or unexplained.
6.2.3 Justice in Healthcare
Justice is another useful concept when considering health equity. It is defined as maintenance of what is just or right. In terms of healthcare, this means we try to ensure no one is unfairly disadvantaged when accessing health services. For example, in the UK’s National Health Service (NHS), the principle of justice is the basis of free prescriptions for people on lower incomes. Even in free-market systems such as the United States, justice is the reason that even without private health insurance everyone is eligible for emergency care and other basic entitlements. Social protection mechanisms (normally provided by the state) seek to safeguard those most vulnerable.
6.3 The Social Determinants of Health
The social determinants of health, wider determinants, or socio-economic determinants can be considered to be the upstream, ‘causes of the causes’ of ill health. The WHO describes these factors as ‘the conditions in which people are born, grow, live, work, and age’ and the ‘fundamental drivers of these conditions’ such as income, unemployment or job insecurity, education, conditions at work, access to sufficient food, housing, basic amenities, and the environment and social inclusion or issues of discrimination [3]. Evidence shows that these social determinants have a greater impact on health outcomes than access to medical care, for example [Reference Braveman and Gottlieb4].
6.4 Measuring Health Inequality
Socio-economic status (SES) can be used to analyse health inequality across income, education, or occupation as it relates to an individual or household. In Canada, New Zealand, and the UK (among others), the term ‘deprivation’ is used at a neighbourhood level as a proxy of lower SES. The UK’s Indices of Multiple Deprivation is one such measure that combines information about income, employment, education, health, crime, housing, and living environment [5] and is commonly used in research and government to attribute deprivation by postcode. The Equality Trust has collated information from multiple data sources, comparing domains of health between more and less equal societies. The level of inequality in a society can be considered by comparing how much richer the richest 20% are than the poorest 20% (this is sometimes measured using the Gini Coefficient, for example). In more equal societies, including Japan and many of the Scandinavian countries, the difference is 4x-fold, whereas in most unequal societies (including Singapore, the United States, Portugal, and the UK) the difference may be up to 10x-fold [Reference Pickett and Wilkinson6].
Epidemiological research consistently finds that health indicators, including infant mortality, child wellbeing, obesity levels, and overall life expectancy, are worse in more unequal countries and that health is often more closely related to income differences within high-income societies, more so than between such societies. Social problems follow the same trend with increased problems with higher drug use, lower educational scores, increased school dropout, and higher teen pregnancy rates. Altogether, this demonstrates the interconnectedness of economics and the sociocultural environment.
6.5 Social Determinants of Health and the Pillars of Lifestyle Medicine
We will now explore how social determinants and inequalities influence behaviour and health outcomes through the lens of the six pillars of Lifestyle Medicine.
6.5.1 Sleep
Lower SES is generally associated with poorer sleep across a range of sleep metrics. Less formal education, neighbourhood deprivation, and higher unemployment have all been associated with suboptimal long-term sleep trajectory across racial groups [Reference Nyarko, Luo, Schlundt and Xiao7]. Less healthy sleep has been observed among children and adolescents from less affluent homes [Reference Etindele Sosso, Kreidlmayer, Pearson and Bendaoud8]. In adulthood too, poorer SES is associated with more frequent sleep disturbances and shorter sleep.
Among cohabiting adults, lower SES is associated with shorter duration and poorer quality sleep, with low sleep efficiency and long wake periods [Reference Saini, Keiley, Fuller-Rowell, Duke and El-Sheikh9]. These associations are most pronounced when measured through income-to-needs ratio (men and women) and perceived economic wellbeing (women only). Partner effects have also been observed in research, such that men’s employment status has been associated with women’s longer sleep duration and greater sleep efficiency. Consideration of family context is thus important in assessing sleep.
Given the evidence that sleep affects productivity and absenteeism [Reference Glick, Abariga and Thomas10, Reference Itani, Kaneita and Otsuka11], it has been argued that good-quality sleep should be an important Public Health target. Such interventions can also be delivered in Lifestyle Medicine and be beneficial for individuals, for population health, and the wider society.
6.5.2 Nutrition
Food insecurity, defined as having limited access to food due to money or other resources, may heavily influence an individual’s food choices and ability to follow a ‘healthy’ diet. People experiencing mild food insecurity may experience worries about obtaining food, which may in turn negatively affect their wellbeing. With worsening food insecurity, people may compromise on the quality of food, leading to malnutrition of various types – obesity, micronutrient deficiency, or both. The obesity crisis among children has been attributed to low-cost, high-calorie food [Reference Jasbir, Lamb and Ogden12]. At its most severe, food insecurity may lead to an individual having insufficient quantities of food experiencing undernutrition (stunting or wasting) or starvation. Food insecurity is a significant problem in the UK. According to the charity the Food Foundation, 18% of households in the UK were experiencing food insecurity in 2022 [13].
Yet even if finances are not a major problem, the ‘foodscape’ (the availability of food locally) also shapes an individual’s ability to achieve a healthy diet. More takeaways and fewer outlets for fresh unprocessed foods predominate in more deprived neighbourhoods [Reference Maguire, Burgoine and Monsivais14].
6.5.3 Physical Activity
The inequalities in physical inactivity may be less intuitive than they are for nutrition, but are just as profound. Socio-economic status is closely associated with levels of physical activity (PA), including among older adults [Reference Stalling, Albrecht and Foettinger15]. Analyses in the UK have demonstrated that socio-economic background is predictive of PA levels [16]. People who are or have been in routine/semi-routine jobs, those long-term unemployed, and those who have never worked are the most likely to be deemed physically inactive (33%) and the least likely to achieve the recommended levels of PA (54%). Conversely, people in managerial, administrative, and professional occupations were the least likely to be inactive (16%) and the most likely to be active (72%). The same survey identified that disabled people are almost twice as likely to be physically inactive (43%) compared with those without a disability (23%). This disparity increases in-line with the number of impairments a person has.
Sex is also associated with PA, with women more likely to be inactive than males, a trend observed across multiple global regions [Reference Guthold, Stevens, Riley and Bull17] with social and cultural norms playing a role.
Improving PA in a consultation will need policy work to address population disparities as well as improving access to safe green spaces for PA or facilities for sport. Without this, the inequalities that already exist for these vulnerable groups are likely to increase.
6.5.4 Mental Wellbeing
The prevalence of mental illness is correlated with greater inequality among high-income countries [Reference Saini, Keiley, Fuller-Rowell, Duke and El-Sheikh9]. This association is stronger for anxiety disorders, impulse control disorders, and severe mental illness, and weaker for depressive illness. It has been proposed that failure to maintain position in the social hierarchy, as may be the case for those among lower SES groups, may be associated with feelings of shame and poorer mental wellbeing. The relationship is likely to be bidirectional, with mental illness potentially impairing an individual’s ability to work, and lack of work, in turn worsening mental health [Reference Drake and Wallach18]. Indeed, purposeful work is considered an important mental health intervention and frequently has a role in mental health recovery [Reference Modini, Joyce and Mykletun19].
Further to this, lack of work may lead to reduced socio-economic position, which is an additional risk factor for poor mental wellbeing [20]. Mental wellbeing is further impacted by poor sleep, poor diet, lack of PA, poor relationships, and consumption of tobacco, alcohol, or drugs. As discussed throughout this chapter, these six Lifestyle Medicine pillars are all negatively mediated by SES.
6.5.5 Avoidance of Harmful Substances and Behaviours
Mental illness and substance misuse frequently co-occur. Whilst this Lifestyle Medicine pillar incorporates a wide range of substances and behaviours, we will focus here on smoking and alcohol, because of their prevalence in modern society.
Smoking is the greatest preventable cause of death and illness in the UK; higher smoking prevalence is associated with almost every indicator of deprivation or marginalisation. Cumulative disadvantage increases the likelihood of smoking. Smoking is more prevalent in people without qualifications, people with lower income, the unemployed, homeless people, people living with a mental health condition, those in contact with the criminal justice system, social housing residents, looked-after children, and lone parents. Consequently, smoking is the single most important driver of health inequalities [21]. It has been estimated that the specific contribution that smoking makes to health inequalities is between 30% and 50% of the difference in mortality between the lowest and highest socio-economic groups [21, 22].
Turning to alcohol, people in lower socio-economic areas tend to drink less than those from higher socio-economic areas [23] but experience a higher burden of alcohol-related harm [24]; this phenomenon has been termed the ‘alcohol harm paradox’. Compared with those living in more affluent areas, people in the most deprived fifth of the country are up to five times more likely to die of an alcohol-specific cause or be admitted to hospital because of an alcohol-use disorder [25].
Unfortunately, misuse of alcohol tends to worsen social problems, including employment issues, crime, and domestic violence. In addition, alcohol use also impacts other Lifestyle Medicine pillars: worsening sleep quality, negatively affecting mental wellbeing, being frequently associated with poor dietary choices, and the development of vitamin deficiencies. Thus, a vicious cycle of worsening health inequality is perpetuated.
6.5.6 Healthy Relationships
Many life events that are associated with disruption of social ties and increased loneliness may also be associated with socio-economic adversity. These include unemployment, family breakdown, homelessness, leaving care, refugees awaiting asylum trials, and uncertainty about the future [26].
At a societal level, increasing inequality is associated with diminishing trust between individuals, and reduced quality of social relations. This may be due to the general tendency of people to befriend individuals from a similar social setting. It has been suggested that when there is greater difference (inequality) between population groups, then building trust and relations between them is harder.
Reduced social connection itself has health, behavioural, and economic consequences, including increased risk of cardiometabolic and mental health conditions, lower PA, poorer diet, and increased smoking and alcohol use [27]. People with low SES and who lack social connection may also have fewer material resources to manage lifestyle-related illness.
6.6 The Role of Lifestyle Medicine in Addressing Health Inequalities
Historically, Public Health has been synonymous with ideas of addressing the social determinants of health. This conceptual approach emphasises the need to tackle determinants that include education, housing, and work environment – as much, and possibly more, than traditional health services (Chapter 2). Such intervention is visualised in the famous Policy Rainbow [Reference Dahlgren and Whitehead28] that communicates the possibilities of intervening at multiple levels (Table 6.1): socio-economic, cultural, and environmental conditions; living and working conditions; social and community networks; and individual lifestyle factors. Of course, Lifestyle Medicine pertains more to the latter than the other layers, but potentially has a role in each.
Table 6.1 Comparison of roles in addressing health inequalities
| Socioecological level | Pillar | Example intervention | Who? | |
|---|---|---|---|---|
| Lifestyle Medicine | Public Health | |||
| Individual lifestyle factors | Healthy relationships | Social prescribing | ✓ | |
| Nutrition | Nutritional counselling around preparing food on an on a budget | ✓ | ||
| Social and community networks | Healthy relationships | Volunteering | ✓ | ✓ |
| Physical activity | Park Run | ✓ | ✓ | |
| General socio-economic, cultural, and environmental conditions | Healthy relationships | Policies and laws addressing discrimination and marginalisation | ✓ | |
| Physical activity | Increasing availability of safe and attractive public spaces for physical activity | ✓ | ||
| Harmful substances | Laws around smoking in public places, alcohol taxation | ✓ | ||
| Nutrition | Limitations on establishment of new fast-food outlets in an area | ✓ | ||
Both the specialities of Lifestyle Medicine and Public Health are concerned with addressing the inequalities outlined here, but they deliver interventions within different settings. Whereas Lifestyle Medicine acts at the level of the individual, Public Health usually seeks to address the upstream drivers at scale to a population. For example, in the context of nutrition, Public Health attempts to influence the built environment and availability of food, whilst Lifestyle Medicine has a role in nutritional education within consultations or smaller groups. There is however substantial overlap, and ambitious Lifestyle Medicine practitioners may well be at the forefront of advocating for upstream changes to social determinants.
To effectively tackle lifestyle-related health inequality at an individual level, it is important to understand and target the specific and different needs of people from less affluent backgrounds, and their specific barriers to adopting a healthy lifestyle. Identifying barriers, levels of knowledge, confidence, activation, and motivation will mean that clinicians practicing Lifestyle Medicine will be able to tailor the support required for lifestyle change; some people will need more support than others. For example, it may be important to consider the cost and availability of childcare in order that parents have the time to take exercise or other positive health behaviours, some people may not have access to a safe space for PA, others may have low health literacy and struggle with food insecurity, debt could be contributing to anxiety or precipitate misuse of alcohol as a coping mechanism, and so on. Interventions that improve health in society overall may not always specifically consider the needs of less affluent groups. In turn, ill-considered interventions (in Lifestyle Medicine and/or Public Health) may inadvertently increase inequality or exclude those facing deprivation.
Lifestyle Medicine must acknowledge the different potential levels of action when working to address lifestyle-related health inequality. Insufficiently exploring and discussing lifestyle at an individual level may be unsuccessful when that individual returns to a family circle, community, institutional environment, or wider society where unhealthy lifestyle choices may be normalised. Success is most likely if a patient’s problem is tackled at multiple levels.
6.7 Conclusions
There are significant differences in health outcomes across different population segments, both within and between countries, and many of these are preventable. Socio-economic status is an important driver of health inequality, particularly in more unequal societies, and has impact across the six pillars of Lifestyle Medicine, which are frequently interlinked and mutually exacerbated. There are multiple potential points and levels at which Lifestyle Medicine interventions may address health inequality and achieve greater justice in health. The greatest chance of success may be reached by tackling the issue at multiple levels, allying with Public Health advocates and others, and recognising a more equal society as a mutual endeavour.
