Comment: We are familiar with the rise and fall of the Covid-19 pandemic playing out over months and years, but we have been living through a pandemic which has been playing out over decades. That is, an obesity pandemic, a pandemic which governments all over the world seem reluctant to do anything about.
A pandemic is distinct from an epidemic. The latter describes the rise and fall of a disease over time within a population. A pandemic is when this occurs across the world, as it has with obesity, a disease which is having myriad health effects.
The big picture of the obesity pandemic has just been published in the top scientific journal Nature. The extraordinary study traced the different patterns of increase in obesity prevalence in 200 countries over 45 years, using data from over 4,000 studies and 230 million participants.
In an accompanying commentary to this paper, I distilled two critical insights from these patterns. The first is that obesity has increased in every single country, rich and poor, where bulging waistlines are leading to the rise in type 2 diabetes – a chronic, expensive and often debilitating disease. I am also sure that most of the billion or so people in the world now living with obesity never wanted to be trapped in this pandemic.
You would think the response to this would be like a response to any pandemic: to prevent a huge, global driving force pushing obesity onto all countries and easily overriding the will of people and governments.
What is that global force? It’s not a global collapse of individual responsibility or caring about health. The only plausible cause of the pandemic is the displacement of real foods in our diets by ultra-processed foods (UPFs) over the past half century, a ‘UPF colonisation’ of our food systems driven by the corporate pursuit of profits, no matter the societal costs.
Highly profitable UPF corporations are experts at producing attractive, hyper-palatable, highly marketed, convenient, foods from cheap commodity ingredients, and lace them with additives to give them the irresistible taste, mouth feel, shelf life and addictive hits.
Why haven’t countries, like New Zealand, which have known for decades about junk food and rising obesity, and its health consequences, done something about it?
Yes, most people like the taste and convenience of UPFs but there is also strong public support for policies like banning junk food marketing to kids, having mandatory front of pack labelling for healthiness, and taxes on sugary drinks. The reason for policy inaction is that the lobbying power of the UPF corporations has always been greater than any government’s willingness to take a stand on behalf of the nation’s health.
The second major insight from this big study is that there are quite different patterns of increasing obesity. New Zealand, with other high-income, English-speaking countries (Australia, Canada, the US, the UK) was affected by the obesity epidemic early, climbing up to high rates but have started to plateau since about 2000. European countries also plateaued from about that time. Coincidentally, and perhaps causally, media coverage about obesity hit the headlines in the early 2000s and continues to do so. This suggests that our levelling off in obesity prevalence is likely to be due to increased media coverage and general population awareness rather than government action.
Another noticeable pattern was the recent and accelerating increase in obesity among lower-income countries, especially in Asia and Africa. The displacement of traditional foods and diets by UPFs is most rapid in these regions. Pacific countries top the global league tables for obesity prevalence.
National wealth does not explain everything. Some high-income Asian countries, like Japan, Korea, Taiwan, and Singapore, have had only slow rise in obesity over the past 45 years. They have maintained strong traditional and healthy cuisines and culturally have very thin ideal body sizes, especially among women.
Explaining these different patterns of obesity trajectories is complex. Many influences are at play – economic, cultural, political, local built environments and transport systems.
A few years ago, we postulated four stages of an ‘Obesity Transition’. Poorer countries in Stage 1 have low overall obesity but with some increases among wealthier, middle-aged women in urban areas. In Stage 2, especially in middle-income countries, obesity rates increased substantially, among women and increasingly among men and children. Importantly, obesity is still more prevalent among wealthier groups and in urban areas.
New Zealand and many other high-income countries are in Stage 3 where obesity is high and rising, and men and women have similar rates. Here, in Stage 3, the socio-economic gradient has flipped with obesity being more common amongst lower-income groups and in rural areas.
Stage 4 is the epidemic turning the corner with obesity prevalence decreasing. This was a bit theoretical because, when we wrote that paper, no country had reduced its obesity levels.
But this big study has now identified some early reductions in countries like France, Portugal and Italy. They have strong traditional cuisines and less infiltration of their food systems by UPFs. In these countries, women and children and wealthier women are leading the way to reducing obesity.
For New Zealand, the lessons are clear. We need to ensure children are exposed to healthy whole foods. An expanded, well-designed Ka Ora, Ka Ako school lunch programme can do just that. Also, we need to reduce the dominance of UPFs which swamp our food environments, sponsor our kids’ sport, and target adolescents on social media. That requires political leadership.
