Understanding Obesity (Part 2): Whose responsibility for obesity?
Now that we know obesity is a public health crisis requiring urgent action, we may wonder - what causes it? After all, effective solutions require tackling the root causes of the problem. This part therefore aims to shed light on five of the many contributing factors to obesity.
1. Choices
Nothing much to elaborate here; choosing to eat more and moving less will result in weight gain. More calories in, less calories out - basic law of thermodynamics. Boring. However, many people are quick to go down the reductionist route by placing ALL the blame on the individual’s personal choices. If it’s just a matter of people needing to make the right choices, if it’s really that simple, we would have tackled obesity long ago. Blaming obesity solely on individual choices does not answer WHY we are increasingly eating more and moving less. Take a look at this timeline of adult obesity in the U.S below by the CDC, similarly reported in other countries across the globe.
The rate of obesity has tripled worldwide since the late 1970s. If obesity is simply caused by a lack of personal responsibility, what happened in the late 1970s? Did everyone collectively lose their rationale - maybe everyone got together, decided to YOLO and go buffet in life? Definitely possible (cue the entrance of conspiracy theorists), but highly unlikely. Did some form of transcendent power strike the DNA of humans collectively that made us evolve into a bunch of lazier and much more ravenous creatures? Scientists have studied evolutionary changes during this period and concluded that nope, our gene pool has remained constant; any changes in the gene pool would take hundreds of years to produce an obvious effect across a global population anyway. This means that:
the global rise in obesity is not because of any significant genetic changes,
people did not willingly choose to eat more and move less,
there are other external factors that mainly drives the obesity epidemic.
Consider a class of 10 pupils. When only one pupil gets very low grades in an exam and the other nine got full marks, the one pupil is considered mainly at fault. Perhaps they need to study more and work harder to get a good mark. But when six out of ten got very low grades, is it still the pupils’ fault? Would we then tell the children to study more, while everyone else (i.e the teacher, parents, education system) just remain in inertia, or goyang kaki?
Similarly, when 63% of the people in Brunei are living with overweight and obesity -- is it still entirely their fault?
2. Environment
(Please bear with me, I’m trying my best not to turn this section into a whole thesis).
The environment is one of the largest contributors of the rise in the obesity epidemic. This is based on rigorous academic evidence and decades of research. Essentially, the environment has generally promoted the increased consumption of unhealthier food through a rapid increase in its:
availability : since the 1970s, the food environment underwent a shift from predominantly fresh produce to a more ultra processed diet. Food are being processed to the point where they look nothing like what they originally look like, stuffing them with cheap ingredients such as sugar, salt, trans-fats and flavourings to enable mass production to be sold at cheap prices and for easy consumption. These products are called ultra processed food, and examples include soda, sausages, nuggets, sugary cereals, instant noodles, crisps, chocolates and so on. Because of its poor nutritional profile, ultra processed food has confidently been associated with higher risks of obesity, heart disease, type 2 diabetes, cancer, depression, asthma, etc. And we, especially young people, are consuming more of this than ever.
exposure : we're talking about the aggressive marketing strategies that has been employed especially by the fast food industry and beyond. I remember going back home from the airport after my 14-day COVID quarantine being bombarded by roughly 10 billboard ads, majority of which are advertising for fast food. As I went out and about for the next few months, I realised that we are exposed to food companies constantly fighting for our attention through their advertisements, whether in the form of billboard ads, physical outlets, leaflets, newspaper ads, TV ads, social media ads, social media influencers, event sponsorships, - the list just goes on! In fact, 46% of the annual advertising budget in the UK goes to soda, confectionery and snacks, while only 2.5% goes to fruits and vegetables. Imagine if it was the other way around.. One can only dream... The point is, we as humans are constantly being tempted with unhealthier food rather than healthier food, which in turn, drives up our purchase and consumption of unhealthier food products. I also particularly like this photo taken in the UK that just showcases the pedestal unhealthier food ads are being placed on, i.e. same level as public health ads. Oh, the irony! (Good news for Bruneians - a code of conduct on responsible food marketing has been implemented recently to shield our children from these ads! Just what we need, priority on children’s health > anything else.)
portion sizes : certain food such as pizza and soft drinks underwent a significant increase in portion sizes from the 1970s to 2000s. Just a few days ago I went to to a fast food outlet and noticed that, as usual, the default drink choice is soda, but the default size is now the large one as compared to the smaller one that I remember seeing 3 years ago before I left the country. I was also informed that some other outlets have been asking customers to upsize their drinks by default. Just how necessary is this? We may think this is not a problem because people supposedly eat according to their physiological needs and can simply stop when they’re full, and so they wouldn’t need to finish the whole portion. But research leading to the discovery of what is known as the portion size effect (PSE) has suggested otherwise; the more energy-dense food people are served, the more they tend to eat.
The 21st century environment is also promoting physical inactivity and a sedentary lifestyle compared to the past centuries. Opportunities for physical activity especially in high-income countries have declined possibly due to the rapid urbanisation, rise in 9-5 jobs and more people relying on motorised transportation methods. Although research has shown that physical activity (PA) among adults done during free time have increased in the past ~30 years, a simultaneous decrease was found in physical activity done while working in the past ~50 years. Young people are also observed to be more physical inactive levels throughout the years, though locally... I like to think that our younger people are getting more physical-activity-conscious nowadays since applaudable efforts to widen opportunities for PA such as the launch of Bandarku Ceria and the opening of numerous hiking sites and gyms booming in 2019-2020. But this could just be my skewed perception looking at a small and specific demographic of the population - more formal research needs to be done.
So, we know that the environment is the main factor that drives up the obesity pandemic. But if we are all living in an environment which predisposes us to develop obesity, why don't we ALL have obesity? This tells us that there are other factors that makes an individual more likely to act on the environment's impulses - such as their socioeconomic status (income, education) and especially their genes.
3. Income
Research among developed countries such as the UK, Australia, Germany and Singapore has shown that people who are from lower income level are significantly associated with a higher risk of obesity. This graph below just shows how stark the inequality is between the most and least deprived areas of the UK. Note also how rapidly-widening the gap is over the years!
Why are poorer families in developed countries more likely to live with obesity?
Food that are more nutritious are often less affordable than nutritious food. I particularly love this infographic showing how in order to meet the general recommendation of a healthy diet in the UK, the poorer families would have to spend 39% of their income on food alone, while this percentage steadily decreases as your income increases, to as low as 8% for the richer families. The same pattern is reflected in many other countries including the USA, Australia and
This inequality is not just seen within countries, but also across countries. One study across 18 countries identified that in order to meet the recommended guideline of 5 servings of fruits and vegetables per day, families in lower income countries would need to spend 52% of their income on them, those in middle income countries would need to spend 17% while those in higher income countries would need to spend a mere 2% of their income.
The price gap between healthier and unhealthier food can then affect people's purchasing behaviour, where families from lower income are forced to prioritise quantity of food over quality. For some of us, we are privileged enough to be able to choose food that are delicious, nutritious, and of different variety each time. But for some others, especially among families with poorer background battling food insecurity, they can only afford to eat in order to feel full and get through the day. Research has shown how poorer families always have to 1) balance out their choices of food with the utilisation of scarce resources, and 2) make judgment of food prices relative to other food prices. Combining this with the known fact discussed above that unhealthier food are FAR more aggressively marketed (almost 20 times more) than healthier food - we are left with a group of the population who are predisposed to choosing food that are mainly satiating, and less nutritious than the recommended guideline.
In fact, we know that even more factors than those discussed above can contribute to people from poorer families having an unhealthier diet. One of them is, on top of the price gap of groceries, we have the price gap of fast food. Parents who are busy and don't have much time to cook nutritious and homemade food often resort to fast food to sustain their family. Sure, we have a plethora of fast food options to choose from (and they just keep increasing - don't get me started). But what kind of fast food is both affordable and nutritious? Nasi katok costs $1 while a balanced meal costs $5 (minimum), and this disparity is seen all around the world.
Given all this, we still have the audacity to say that obesity is simply caused by a lack of willpower?
Gimme a break. It is clear that people who are not as financially privileged requires additional support in order to maintain a healthy weight. If not through finance, through education (further explained in Cause 4), or even better - both!
Side note: Despite the overwhelming evidence that having low income is associated with higher risk of obesity, there is also emerging evidence showing the possibility of the opposite (reverse causality); living with obesity is ALSO associated with having low income due to stigmatisation and discrimination. So basically... living with low income may cause people to live with obesity, and likewise living with obesity may cause people to live with low income. This syndemic is similar to the that of obesity and mental health issues discussed in Part 1.
4. Education
Health is not formally taught in most schools. Health starts at home. Because of this varying education level and awareness about health across the population, each family has very different approaches of ensuring how their family can grow up adopting healthy behaviours.
Generally, the likelihood of having obesity increases with decreasing level of education. This was observed in many countries including Taiwan, Saudi Arabia and Iran. The trend is similarly reported in OECD countries such as Australia, Canada, England and Korea as shown below.
This may be because more educated families tend to have healthier lifestyles and are more aware of what the causes and consequences are of obesity. If a family is lacking awareness and knowledge on certain aspects of health, such as in nutrition - eg: what the importance of consuming enough fibre is, what exactly constitutes a balanced diet, how to cook nutritious meals under time constraint etc - then their family will be less likely to adopt healthy (protective) behaviours.
Awareness on the causes and consequences of obesity indeed remain low within many communities. In one study, 76% of young people surveyed believe that "obesity has a genetic cause and that there is nothing much one can do to prevent obesity". Almost 30% of them also believe that even when substantial changes were made to one's lifestyle, obesity cannot be prevented. In the UK, around 3 in 4 people didn't know that obesity can cause cancer - the leading cause of death worldwide.
Not only are people unaware of the causes and consequences of obesity, many people even show a general lack of understanding of obesity itself. It was found that among 401 Malaysians surveyed, 92% of those with obesity underperceive their weight, thinking that their weight is at a normal range or lower than it actually is. This is particularly concerning, because any intervention efforts to reduce obesity rate within a community will just bounce back by the majority of the target group who think the messages are 'not for them because they don't have obesity' when they actually do.
All in all, if you come from an educated family background - good for you. If you have the opportunity to study more about health, or human/medical sciences - good for you. But what about those who do not have all these privileges?
Side note: There is also evidence showing how having lower education level is not just associated with higher level of obesity in a direct manner, but also indirectly where having a low education level may contribute to households having a lower income, and as discussed above in No.3 -> may result in a stacked effect on obesity. This is called the mediation effect and more explanation can be found here (pg 133).
5. Genetics
Over 200 genes influence our body shape and size. This include genes that affects how frequently we feel hungry, the rate that we burn calories, our metabolism rate, and many more! Some of these individual genes can increase our likelihood of becoming heavier while some other genes tend to make us lighter depending on whether it is 'switched on or off'. And this mix of 'on and offs' for EACH gene is always going to be different between individuals (polymorphism).
Because of our own 'mixed bag' of ~200 obesity-related genes interacting with each other, some people will find it much harder to resist that bar of Kinder Bueno sitting on the cashier till, while some others wouldn't even bat an eye. Some people naturally feels full after a bowl of rice, while some others would need three bowls. Some people can store a large amount of fats while some others can store only half of that amount before those fats (lipids) seep into other tissues instead such as muscles and potentially cause diseases (lipotoxicity).
Our genetic differences within the population explains why some people respond differently to the obesogenic environment we live in. It is not as simple as our genes determining whether we develop obesity or not. We simply can't be saying "Oh it's in my genes, got it from my parents~" to justify our lack of effort to address obesity. There's no single gene that makes people develop obesity. But rather, our mixed bag of genes determine our susceptibility to obesity. For people with many of those genes that makes it likely for them to gain weight easily 'switched on' -> they will be more susceptible to obesity because their own biology makes it much harder for them to fight back the temptations of the obesogenic environment.
Because this concept is so difficult to be understood by people who have always had a healthy weight all their life, privileged with not having the genes raising the likelihood of obesity 'switched on' -> they tend to blame obesity solely on the individual's personal choice. Because their own biology makes it easier for them to resist the temptations of the obesogenic environment.
As Joslin - an American doctor - described almost a century ago which pretty much summarises the role of genetics in obesity:
Genetics probably loads the gun, while lifestyle in our obesogenic environment pulls the trigger for the spreading of the obesity epidemic.
Does this mean that people who have genes that makes it more susceptible to develop obesity can simply blame their genes for their weight?
No! Not entirely. They can and should apply the same general concept of weight loss to counteract the risk of obesity, i.e. - eating balanced meals, doing plenty of physical activity (going back to the boring law of thermodynamics: more calories out than in = weight loss). However, it will be especially harder for these people to achieve it due to their obesity-encouraging genes. They have to put in more effort to lose 1kg than someone with less of the obesity-encouraging genes.
What this means for those with obesity: Your own genes and biology is one of the factors why your BMI is considered high at the moment and why it feels so difficult to lose weight. It is important for you to understand this, so that you don't beat yourself up too often! It is not entirely your fault. It will be hard, and in fact it will be harder than many people, but what matters is for you stay focused in putting in the work to get there!
What this means for those with healthy weight: It's about time for you to stop blaming everything on the individual's personal choice when you don't even know how difficult they have it and how much they have been trying to fight their own biology. Don't act like you know their struggles just to shame and stigmatise them because you don't and neither do I. Leave it to their close family and personal doctor to consult them.
What this means for policymakers: We have a duty in making sure that 1) the environment is as conducive as possible to live a healthy lifestyle to avoid 'triggering the gun', and 2) people are aware that genes play a big factor too (of around 40-70%) in determining someone's weight and its not just entirely down to the individual.
Side note: The genetic explanation above which acknowledges the role of hundreds of different genes in the development of obesity is applicable to the majority of people living with obesity (polygenic obesity). However, there are also the minority of people who develop obesity due to mutation in single genes (monogenic obesity / syndromic obesity) which warrants a separate and more technical explanation.
Bottom Line
To summarise the cause of obesity:
As mentioned in Cause 1, how we develop obesity is always down to the individual eating more and moving less. But as explained in Cause 2, 3, 4 & 5, the complex interaction between the environment, the individual's socioeconomic conditions, and their own biology explains why it is so difficult for some people to eat less and move more.
To summarise the cause of the obesity pandemic:
Personal choice explains why one individual may develop obesity, but the environment explains why more people across the whole world is developing obesity. Our socioeconomic conditions and especially our genetics then explains why not ALL people develop obesity as a response to the change in environment.
So what should I do with all these information?
That's entirely up to you and how much you understood! But the reason why I brought this topic up is because I'm personally sick and tired of hearing people living with obesity being blamed for their "poor choices in life", "lack of self-control", for "being gluttonous", "lazy", etc.
As I have hopefully explained, obesity is undoubtedly very complex and a result of so many factors. These five things I mentioned above? There's. So. Much. More.
Click here for a clearer view.
So the next time we blame it all on people with obesity - check your privileges. You're rich? You're naturally slim? You're educated? You don't have as much obesity-encouraging genes? Good for you. Perhaps that tends to make you feel entitled to say that people who are living with obesity just needs to make "better choices".
But understand that you have it easier in maintaining your healthy weight, while people with obesity most likely have it harder. The least you could do is really be sympathetic and understanding, acknowledge their struggles, and certainly avoid shaming and stigmatising them. Make it easier for them by providing healthier choices and support them physically and emotionally in their goals of achieving a healthy weight!
Aren't you just giving an excuse for people to live with obesity?
Disclaimer: My BMI sits quite well on the healthy range at 23 kg/m^2. I am nowhere close to having obesity, nor do I have any family members, partners or close friends living with obesity. I literally gain NOTHING to be making up an excuse for people to live with obesity. Quite on the contrary, I understand its dire consequences as I have outlined in Part 1, and I have even mentioned personal choice as one of the causes above. It's not about giving excuses, but simply an effort to give voice and justice to those who has been silenced.
I hope I have gotten my point across through this post and the previous one in my Obesity Series! Let's all be more-informed members of the society and support each other in achieving our health goals :)
*Note: For simplicity purposes, ‘unhealthier food’ in this post refers generally to food lower in nutritional profile, and food high in fat, sugar and salt (HFSS). In reality, we should understand that food does not exist in a binary manner.
Unlinked References:
Gene Eating by Giles Yeo (Book)
CMO Independent Report: Time to Solve Childhood Obesity by Professor Dame Sally Davies
