Hey you guys. I’m Jack Ruston, welcome to Ruston’s Boneyard. I hope you’re all having a good week.

Now today I’m going to be doing something slightly different. Rather than my usual recipe video, I’m going to be starting a series of videos addressing one of the most prevalent, and pertinent questions that we face today, ‘How Do I Lose Fat?’. And in this series I’m going to bring together the work of some far finer minds than my own, to collate that information, and try to present it to you in a way that’s reasonably straightforward. Now, it is a complex subject, it’s multifactorial, and there’s a lot of interplay between those factors. I was thinking about how best to present all this to you, and what I decided to do was to write the whole lot out long form, break it up into chunks, and create this series of videos, which will be accompanied by the full text in the form of blog posts with some references for further reading. Now accordingly, I am going to be reading this to you, it will be obvious that I’m reading and I hope that’s ok. 

Before I begin I’d like to offer this disclaimer – I am not qualified to give any sort of medical or dietary advice, and nothing in this material should be considered as such. The opinions expressed here are my own, and for the purposes of discussion only. Please consult a qualified medical professional before undertaking changes to your diet. 

So here’s the first part of this How Do We Lose Fat series, The Evolutionary Disadvantage. 

Perhaps the most prevalent question of all in this whole food, wellness, diet, lifestyle space is ‘How do I lose weight?’ and it is a question worth asking, not just because many of us want to look lean, we want to rebalance our body composition a bit, but despite what some people might try to claim, it is extremely difficult to be both obese and healthy. 

Obesity, which is now nothing short of an epidemic in the developed world, correlates so tightly with serious chronic disease, there is really nobody in the medical community, clinicians or researchers who would argue that it’s healthy to be obese. And we do now understand some of the direct, mechanistic links between the quantity, location and level of inflammation of the fat in our bodies, and the manifestation of a number of serious diseases. This is particularly relevant right now, because one such disease in which we know obesity is a huge factor, and how it is a factor, is Covid. 

Metabolic syndrome, which is characterised by obesity, particularly visceral adiposity, high blood pressure, and high fasted blood sugar and triglycerides, is the most significant risk factor for severe Covid, other than age – and you can argue that increasing age is, to some degree, a proxy for poor metabolic health. 

Now, I’m not trying to get involved in some sort of fat-shaming here – far from it. I’m actually going to be talking about why long-term fat loss can be impossible for many people, and why it is so wrong to draw the conclusion that people lack commitment or willpower when they struggle to lose weight – it is not a character flaw, it is not laziness, or a lack of grit, drive and determination. But the fact does remain, that we can not tackle obesity by simply reframing it, by saying that it’s perfectly healthy, that people come in all sorts of shapes and sizes, describing ourselves as having a bit of a ‘dad bod’ as if it’s an advantage. It may well be attractive to some people, and I’m not here to argue that being fat can’t be sexy, but it isn’t healthy. 

Throughout the Covid pandemic, we’ve all had to take on the responsibility of isolating in order to prevent our healthcare services from becoming overrun with unmanageable numbers of simultaneous severe cases. As we begin to unlock our society, to get back to normal, we have to accept that a responsibility now exists to do the same by addressing our health. It’s foolish to assume that there will always be a highly effective vaccine as Covid evolves, but looking beyond Covid, that underlying metabolic disease that has made the virus so dangerous for some people, is an epidemic all of its own. The cost, the pressure on our healthcare system of treating the vast numbers of people with pre-diabetes, diabetes, and all the downstream effects of those diseases – cardiovascular disease, many cancers, dementia and Alzheimer’s is simply staggering. If we are genuinely concerned about protecting these services, such that when we need them they are there for us over the coming decades, if there’s one thing that we absolutely must do, it is to address the metabolic health of our populations. While metabolic disease isn’t exclusive to those with obvious obesity, it’s fair to say that addressing the obesity epidemic is the defining step in tackling these issues. 

Now, when we talk about weight loss, what we’re really talking about is fat loss. Lean body mass plays a critical role in our health: It acts as a metabolic soak – our muscle absorbs glucose from our blood, storing it as glycogen. It’s metabolically expensive – it raises our metabolic rate, which increases our energy expenditure, and of course it keeps us physically strong, capable and robust. Furthermore it obviously has a significant impact on the way we look, so what we’re really asking is not ‘How do I lose weight?’ but ‘How do I lose fat?’ 

Firstly it might be worth flipping that question around, and asking ‘Why do we gain fat?’ Well there are many factors at play – the means by which we’ve evolved, our biology, the design, composition and availability of our foods, the function and dysfunction of our hormones, and the interplay between all these things, but the simple answer is that we take in more energy than we need, and this is the basis of the classic calories in, calories out ‘Energy Balance’ model, whereby our dietary intake of energy is balanced against the calories we burn. That is fundamentally correct – there are countless studies that show that when we maintain a calorie deficit, we shrink, but as always, it’s not quite that simple – there’s considerable nuance around our what drives our hunger, the food we take in, the ways and rate at which we expend energy, and the way the two sides of that balancing act affect each other, both acutely, and chronically. 

Over the coming episodes, we’ll look at the factors that affect our ability to gain and lose fat, and suggest some strategies for turning those to our advantage. 

So what we’re told is to eat less and move more. We’re told to eat a balanced diet, and to count calories, but what happens is that we go on a diet for a few weeks, strictly following the regime, tracking our calories, struggling out for a jog every other day, and we do lose weight. But the moment we stop dieting, all the weight comes straight back on, sometimes even a bit more, and at a frightening rate. We feel like we’ve failed. We go on another diet, struggling through the misery of significant calorie restriction, the tedium of weighing and tracking our food, finding that we need to eat even less than we did last time, and exactly the same thing happens. Some of us go repeatedly round this cycle, each time cementing the realisation that it’s all pointless, a battle we can’t sustain and will never win. We can’t tolerate endless hunger, or the rigmarole of weighing and measuring our food. We wonder why we’re so weak-willed, why we’re so lazy and feeble, eventually convincing ourselves that it’s our genetics, our age or simply that it’s just normal for human beings to gain weight over time – that it’s unavoidable – and this is not true. 

The holy grail is a situation where we can eat when we’re hungry, stop when we feel full, and maintain a healthy body fat percentage in the process, the way human beings have done for millions of years. To most of us in the developed world, that seems like a pipe dream. We can use the simple calories in calories out model to lose fat and maintain that loss indefinitely, but only if we’re prepared to endlessly weigh and track our food, and tolerate that constant feeling of restriction – something which very very few people can do in the long run. We all know what it’s like when we’ve told ourselves that we’ve hit our calorie allowance for the day, that there’s no way we’re going to give in and eat another bite of anything, yet somehow, half an hour later, we find ourselves, picking absent-mindedly at something from the fridge. Sometimes we go to great lengths to change the goalposts to allow this – ‘Well if I eat less tomorrow then it’s ok’ or ‘I deserve it because X or Y stressful thing happened’, and sometimes it’s almost as if we just forgot, and began eating on autopilot, mind blank, without realising we were doing it. It’s not that we’re weak-willed – the deck is stacked against us in various ways. 

Over millions of years, evolution has selected for human beings who prioritised food. If you were the person who was obsessed with eating, preoccupied with finding food, who would eat as much as you physically could at every opportunity, you were far more likely to survive than someone who was prepared to take it or leave it. What this seeded in our biology was a dopaminergic response to eating – food was, and is addictive – it lights up the reward centre in our brains. We all know that feeling when we’ve got a piece of chocolate in the cupboard, or a cheesecake in the fridge, that we’ve been promising ourselves at the end of the day, and when we finally sit down and tuck in, we feel this flood of wellbeing, even if we know that we shouldn’t be eating that food, because it’s not consistent with our goal of losing that excess weight, which might be the greatest source of unhappiness in our lives. That rush of warmth and comfort is the release of the neurotransmitter dopamine. It’s the same rush that we get from drugs like cocaine. We can see this in kids, because they’re so demonstrative with their emotions. If they’re a bit grumpy or upset and we give them a big piece of chocolate, within a few moments they’re glowing, happy, laughing. They’ll start jabbering on about things they’re pleased or excited about. It’s not a question of energy – they might have just had a meal – it’s that rush of dopamine that’s making them feel great. 

In talking about this, we have to acknowledge that there’s not only a biological, but a psychological component to the way we eat. We may be using food as a way to control our emotions, and at a certain point, our eating can become disordered. This is an extremely complex issue, and it’s beyond the scope of this material, and certainly beyond my paygrade. If you have an eating disorder it’s important to get professional help. If it’s something people are interested in, I can look into finding someone who can talk to us about it. 

Now by contrast, the feeling of hunger is intolerable. It speaks to a primal part of us, and it says ‘If you don’t eat something, you’re in deep shit, you could die’. Remaining hungry when there’s food available to us goes against the very fibre of our being. And it’s not just a feeling we don’t much like: When we restrict our calories, our bodies begin a defensive process of downregulation. We conserve energy. Once that primal part of our brain gets the idea that food is scarce, our metabolism slows, we begin to conserve our fat stores, and reduce our outgoings. We downregulate the production of certain hormones, particularly sex and thyroid hormones. Our brain wants us to rest, save our energy, stop producing any more hungry mouths to feed, and wait until there’s more food available. It’s this process that makes dieting so hard, and regaining the weight so easy. When we begin to increase our intake again, not only are we extremely hungry, but we’re now operating at a lower basal metabolic rate – we need fewer calories. 

It also stands to reason that there was an advantage for those of us who were able to lay down fat quickly and easily when food was available. This selective pressure resulted in the loss of the uricase enzyme, the role of which was to break down uric acid in the body. While primates are still able to do this, humans are not, and that uric acid allows us to more easily lay down fat from the fructose found in ripe fruit. The thinking is that this is what allowed us to thrive as we moved north out of Africa and into Europe. We’d have had less frequent access to fruit, and would have benefitted from being able to more readily lay down fat during those short periods of the year when it was available. 

It’s obvious why those of us who exhibited such a strong affinity for eating, and such a visceral aversion to hunger would have thrived over the past few million years. But today, those traits are no longer an advantage. In the developed world at least, where there is no winter coming, no scarcity to speak of, they are a significant disadvantage – a threat to our health. 

So why have we not evolved further, to select for those who are rather more ambivalent about food? Well because there is little to no evolutionary pressure in our modern environment. However much a person overeats, they will almost always survive to reproductive age, and while metabolic disease and insulin resistance do cause diseases which interfere with fertility – in fact we now have somewhat of an infertility epidemic – we have the medical means at our disposal to help couples conceive where otherwise they might not be able to. In other words, we are using technology to sidestep any brake that evolution might otherwise have put on the proliferation of those particular traits. 

So, if you’re that person who has never seemed to feel full, never been able to stop eating, to put that half-finished packet back in the cupboard, it’s not because you’re weak-willed, it’s because you’re hard-wired to eat as much as possible. It’s that compulsion to eat that got our species to the dominant position it enjoys today. 

In the next episode we’ll look at how our food itself can drive us to overeat. 

Thanks for watching, I hope this was useful. Have a great week. 

Wired To Eat – by Robb Wolf (Vermilion 978-1785041433) https://www.amazon.co.uk/Wired-Eat-Rewire-Appetite-Weight/dp/1785041436/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=1621943533&sr=8-1

Metabolic dysfunction and immunometabolism in COVID-19 pathophysiology and therapeutics: https://www.nature.com/articles/s41366-021-00804-7

Covid-19 And Obesity – The 2021 Atlas: https://www.worldobesityday.org/assets/downloads/COVID-19-and-Obesity-The-2021-Atlas.pdf

Indian-Origin Doctor Alerts Indians To Poor Diet Link With Virus Deaths: https://www.ndtv.com/indians-abroad/coronavirus-indian-origin-doctor-warns-indians-about-poor-diet-link-with-covid-19-deaths-2222425

Effect of calorie restriction on resting metabolic rate and spontaneous physical activity: https://pubmed.ncbi.nlm.nih.gov/18198305/

Fructose metabolism as a common evolutionary pathway of survival associated with climate change, food shortage and droughts: https://onlinelibrary.wiley.com/doi/full/10.1111/joim.12993

A Historical and Scientific Perspective of Sugar and Its Relation with Obesity and Diabetes: https://academic.oup.com/advances/article/8/3/412/4558122

Fructose and uric acid as drivers of a hyperactive foraging response: A clue to behavioral disorders associated with impulsivity or mania? https://www.sciencedirect.com/science/article/abs/pii/S1090513820301215

The dopamine motive system: implications for drug and food addiction: https://pubmed.ncbi.nlm.nih.gov/29142296/