Dietary change: The need to look beyond the individual

As practitioners of Lifestyle Medicine, we all understand the importance of dietary choices as a powerful determinant of health and wellbeing. Many of us will spend a significant amount of clinical contact time working both with individual patients and groups of patients with the goal of influencing their dietary choices. However, I have come to believe that the standard Western medical and political models that place the responsibility for behaviour change and disease almost solely upon the individual must be rejected in favour of a more holistic view if we are to make any substantial and long lasting impact on our patients’ dietary patterns.

Critical as they are, dietary ‘choices’ are proximal determinants of health, in turn determined largely by medial determinants (e.g. stress, relationships, inequality), which are in turn almost wholly determined by the distal determinant of health, the environment (physical, political, economic, socio-cultural)¹. Although our ability to influence medial and distal determinants of health seems progressively less than our ability to influence proximal determinants, it is still vitally important that we recognise these. This enables us to understand, empathise with, and anticipate the challenges faced by our patients attempting to change their dietary patterns, and therefore be able to more effectively facilitate and support these changes. It also enables us to engage with and influence individuals and groups who are in a position to effect changes in policy and culture.

In medicine, we have a term for what are now our most common diseases in industrialised nations: ‘non-communicable’. While it may be true that these conditions cannot be directly transmitted from one person to another, this term also encourages the idea that these diseases cannot be spread. However, when we recognise the precedence of lifestyle factors including diet, activity, and connection over genetic factors when it comes to determining who will and will not develop these diseases we could well argue that they can indeed be spread: the vector is that of the distal determinant of health – the environment.

A talk given by Dr David Katz, former president of the American College of Lifestyle Medicine, emphasises this fact². Dr Katz asks the important but oft-neglected question: if lifestyle is the medicine, what is the spoon? In other words, given that the benefits of lifestyle change are well-established and recognised, and have been for many years now, how do we actually get people to change? He concludes that the spoon is culture, pointing out that so-called ‘healthcare systems’ and clinical counselling do not account for any of the exceptional vitality and longevity enjoyed in the Blue Zones (where people live the longest and healthiest lives). Dr Katz argues that we cannot hope to win the battle against lifestyle illnesses in a culture which accepts, for example, processed grains and multicoloured marshmallows being marketed to children and parents as part of a complete breakfast, and that rewards the invention of foods specifically designed to be addictive and over-consumed.

My experience as co-lead researcher of the BROAD Study, a community-based lifestyle intervention conducted in Gisborne, New Zealand provided insights into the importance of the distal determinants of health³. Prior to conducting this research, I had interned with several lifestyle change immersion programmes based in California. People arrived from all over the United States and even overseas to attend, at great financial expense, and usually staying for at least 10 days. I noticed that despite potentially life-changing results many participants reverted back largely, if not entirely, to their old habits after they returned home. So we decided to emphasise the ‘how’ of dietary change rather than the ‘why’ in our own intervention. It was intended that half of the time spent would be in developing cooking skills, and even the academic or lecture component had a largely practical aspect to it. There were some rather extraordinary results, as we had hoped, and I was confident that our approach had paid off. At 6 months, 25 out of a possible 28 intervention group participants attended follow up and had lost 12.1kg on average. At 12 months, 23 out of 25 returned for follow up measurements and their weight loss was more or less maintained at 11.5kg on average. However, at the same time the cracks were slowly but surely starting to appear. Looking at the data, our measure of adherence – ‘indiscretions’ – all increased significantly in the intervention group the further they got away from the intervention. At 3 months, they averaged 1 indiscretion every 3 days. At 6 months, this had increased to 1 a day on average. And at 12 months, this had increased again to almost 2 a day.

One of the many lessons I have learned from this project is that while knowledge and education about the importance of dietary changes and acquisition of the skills to implement these changes are critical, they are insufficient alone to maintain change in the longterm. Our environment and culture, the distal determinants of health, are in fact what matters most when it comes to longterm outcomes. So, I’m in agreement with Dr Katz when he states that as practitioners of medicine we are: “…called on to preach as well and to innovate empowering programs from the vanguard of true health care reform, rallying the population to nothing less than a cultural revolution that reveres and enables vitality”⁴.

While this sounds a little daunting, by partnering with community groups and local business during our study, we were able to make small but significant changes to the dietary environment and food culture in Gisborne. We had six different eating establishments agree to place meals on their regular menu. A local health food shop broadened its range of plant-based products. So even the relatively small increase in demand for healthier foods generated by our initial groups made some difference to the local dietary environment.

Although not all participants continued with the exact diet we had prescribed for them, knowledge and skills and awareness as a result of participation were nonetheless carried forward and extended to their family and friends, all helping to create the beginnings of a cultural shift in thinking about food. Furthermore, the success of the initial study ensured funding for further interventions to take place exposing more locals and their families and friends to healthier food options both directly and indirectly, and continuing to change the culture within this community.

Notwithstanding these positive shifts, the ‘release’ of the participants back into the surrounds of the standard dietary culture resulted in a degree of recidivism. Despite our best efforts, we had ultimately created a small group of approximately 30 individuals (plus some of their family members and friends) with the skills and appreciation of the importance of their dietary choices on health. This is a very small group within a wider Gisborne community of some 37,000. Of course we would expect there to be some effect of the very strong and very prevalent social and environmental influences on dietary choices back on this group, just as they had in turn made some impact upon their own community.

Adding to the challenges for this group of individuals, Gisborne is the region with New Zealand’s highest rates of socioeconomic deprivation. Recently, the INFORMAS Food Environments report in New Zealand has identified almost four times as many takeaway and fast food outlets, and almost three times as many convenience stores per 10,000 people in the most economically deprived areas compared with the least⁵. There is less room on supermarket shelves in these more deprived areas dedicated to healthy food options. Additionally, providing further context to an earlier study that showed that New Zealand children are exposed to an average of 15 and as many as 27 advertisements at school and in public places (excluding supermarkets, convenience stores, and television) for unhealthy foods⁶, the INFORMAS report also found a higher number of advertisements for unhealthy foods around schools in the most deprived areas compared with the least.

Stress related to lower socio-economic status, in addition to the increased accessibility and advertising of unhealthy foods is also likely to contribute substantially to less healthy dietary choices. In a now well-known study, Shiv and Fedorikhin discovered participants were significantly more likely to choose chocolate cake instead of fruit salad as a snack under conditions where there was a greater demand on their cognitive processing resources – simply having to memorise a 7 digit number rather than a 2 digit number⁷. More recently, and consistent with prior work reporting that stress can lead to increased intake of high-fat, sweet foods, Langer et al. found that women lower versus higher in socioeconomic status consumed more food overall and more high-fat sweet food in particular following a laboratory-induced stressor⁸. Therefore, to positively impact dietary patterns the role of SES and the stress related to this should also be considered. Social policy that aims to reduce income inequality, decrease hardship and increase the wellbeing of those on lower incomes is likely to be substantially more effective than any amount of education we are able to provide as individual health practitioners when it comes to improving the dietary health of the population.

The enormous influence of the food industry and the subsequent need to keep it in check is no better demonstrated than by the example of modern-day Okinawa, Japan, one of the Blue Zone areas. After World War II, the United States occupied Okinawa until 1972, and with them brought new tastes to the island, introducing dairy in the form of Blue Seal ice cream, followed by tacos, and root beer, burgers, and curly fries. Today Okinawans are responsible for over 90 percent of the total luncheon meat consumed in Japan (despite being only 1.1% of the total Japanese population), thanks to Spam. So it’s no coincidence that younger generations of Okinawans are losing their longevity advantage compared to mainland Japanese, and life expectancy at birth for men in Okinawa is now lower than the Japanese average.

Bringing all of this back to Australia and New Zealand, what is demonstrated is the clear need for a major shift in culture that enables changes to be made to our food environment, including regulating the influence of the food industry. No matter how good our skills as practitioners or comprehensive our intervention strategies, we cannot hold our patients’ hands while they visit the supermarket, are exposed to some 5,000 or more advertisements daily, and eat at their favourite restaurants and cafes. We must as practitioners and communities begin to look beyond the individual in order to make a significant and long lasting difference to health.