Horizon on fat: a mechanism is not a cause

Last night, BBC2’s Horizon programme discussed “new” discoveries about what lies behind the “obesity epidemic” that’s assailing us. It was a fascinating programme, and did indeed reveal some very interesting things: but fascinating as it was, it was also deeply misleading.

It was presented by a surgeon who began, so the programme told us, with the belief that obesity was a consequence of people eating too much, and exercising too little. People who exhibited such behaviour did so because they were too weak-willed to do any better. Ergo, what was required was some stern talking, possibly the compulsory viewing of “Supersize vs Super-skinny” (well, had it not been on a rival channel), and for those whose wills were not thus strengthened, the reluctant intervention of an already over-stretched NHS to deal with their inevitable type 2 diabetes, and perhaps an opportunity to recoup some of the money by selling voyeuristic clips of yet another stomach by-pass operation in action. The latter probably wouldn’t be very effective, as the market for gruesome shots of implements that “cut and staple simultaneously” would seem already to be saturated. Every time yet another programme turns the spotlight on our modern gross fatness, and what we might do about it, it seems it is de rigueur to include surgeons at this most unattractive pastime.

But the surgeon starring in yesterday’s programme was obliged to confess to an unsavoury attempt to “take the moral high ground” with her simplistic view that perhaps obese people might have some slight degree of responsibility for their predicament. Because she was wrong. It was all down to genetics. Fat people have a “hunger hormone” that is frankly too lazy to make them feel really hungry when its owner is really hungry, and instead merely makes the hapless person feel a bit peckish all the time. On the other hand, obese people have a “fullness hormone” that never gets its act together at all, and never informs the brain that enough is enough. Later in the programme it was revealed just how the brain was responding to all this hormonal misinformation: thin people’s brains were hardly exercised at all by pictures of cream doughnuts, whilst fat people’s brains produced a veritable frenzy of irresistible urges that their rubbish fullness hormone utterly failed to control.

So obese people are between a rock and a hard place. It is truly wrong to hold them responsible. On the one hand their hormonal chemistry is all up the creek, and on the other their brains conspire against their every attempt at self control. The answer? Well, it seemed to be either hormonal pills, or else an odd side effect from the ubiquitous stomach by-pass surgery referred to earlier, which seemed to have the unlikely additional benefit of re-educating the brain.

It was easy to be carried away with the programme’s scientifically certified approach. Except for one rather glaringly obvious point that was never mentioned at all. The human brain has been as it is for a rather long time. The body’s hormonal chemistry has been as it is for millennia. And yet the obesity crisis that we are constantly being told about has only really taken off in the last, say, 50 years. It’s only reached the consciousness of TV producers in the last 20. Thus I can with absolute confidence say that the cause of this crisis is not to be found in endocrinology or in brain functionality, neither of which has suddenly changed in the last half century. A cause and its effects cannot possibly be separated by such an extravagant slice of time. To believe this proposition is to believe that fundamental aspects of our biology, that never bothered our species before, have suddenly begun to do so. Obviously not.

What the Horizon programme so carefully and thoroughly revealed was not a cause, but a mechanism. The cause is much more obvious, and simpler. It is that our Western diet has changed over the last 50 years in very deleterious, but very profitable, ways. At the same time, our level of physical activity has dropped precipitately. What we can learn from yesterday’s revelations is that this sorry state of affairs does not affect us all equally. Some of us are better equipped than others to resist the doleful consequences of rubbish food and physical slothfulness. True also is the programme’s point that resistance is easier for some of us than others.

What would a rational response be? Surely it would be to attack the causes, rather than to fiddle about with the mechanisms, a fiddling about that is bound to bring other unforeseen consequences in its wake. Why don’t we do this? For two very different, but actually strangely connected reasons. We don’t attack the food culture that is causing our fat malaise because too many people make too much money from its continuance. And we prefer drug or surgical interventions in mechanisms to attacking causes because drugs and scientific medicine are also major money-spinners. Not only that, scientists are as seduced by their flashy toys as any adolescent is by his or her iPad, or Android device, or X-Box console. How much more fun to play with an MRI scanner, or wield a tool that simultaneously cuts and staples, than to wonder about the dominance of hawkers of confectionery or fast food? I can still remember my excitement when I first got to use an electron microscope.

Yes, we should be careful to remember that obese people are indeed people about whom we should care, and not fools that we should castigate. But we should also be very wary of those who would locate every problem in genetics or chemistry, and who seek to minimise human volition or responsibility.


16 thoughts on “Horizon on fat: a mechanism is not a cause

  1. It’s less the dietary changes – I think you rather overstate them – and more a set of changed behavioural characteristics. Most of us are pretty sedentary (sofa, car, desk, car, sofa…repeat) and we also have the money and desire to keep eating when we don’t need to.

    Your point about diet is important since it reflects the undoubted fact that food (as a result of technological improvements) is vastly cheaper than it has ever been – in general terms this is a good thing. Indeed it is a big contributor to the dramatic reduction of starvation, malnutrition and famine across the world.

    Finally, we are nearly all a little fatter than our forebears – just as we’re also a little bit taller – but this is not necassarily unhealthy or indeed a bad thing.

    • Inexpensive food that all can afford is indeed a good thing. Cheap food, bulked up with cheap non-nutritious crap and filled with additives to make it attractive, is not a good thing!!

  2. I’d like to add that the portions in the western world are a) MASSIVE, and b) mostly carbohydrate. I shifted continents from Asia to Australia 4 years ago and can’t ever finish a full meal here. I gained a bit of weight (not much – just went from ‘skinny’ to ‘have you put on a little weight?’) in my first couple of years but that fell off once the copious amounts of sugar and salt and preservatives in the food started making me feel sick. Everything is so heavily processed – I guess it’s the same in the UK?

    And then, yes, there is a food culture – gastropub is the mot du jour in these parts. I can’t do it. Apart from simply being used to eating less of everything, I’m also used to seeing people living off very little, and – while I know the effects are minimal to zero – my conscience simply does not let me eat more than I need to.

    Disclaimer – own experiences and perspectives are in no way meant to be representative of any greater demographic 🙂

    • Thanks for your very perceptive comment. The sources of the obesity epidemic are to be found in Western industrialised food, and of course that food is now not only found in Western industrialised countries! I read recently about the obesity epidemic amongst rich Indians…

      • Oh yes, definitely – that’s why I add the disclaimer. Urban india is no ‘better’ than the west and definitely tends to idealise western (American, mostly) culture. For some unfathomable reason this includes the food as well as such habits as lounging about in coffee shops which is bizarre because for a tenth of the price you could get the perfect cup of tea from a stall.

  3. I only watched three-quarters of the programme and found it puerile. The identical twin phenomenon which managed to show that one twin could be fatter than the other was almost risible because environmental factors and an individual’s experiences are bound to have an effect. It was an attempt to once again find an excuse for the ever-increasing BMI of the average Brit. We simply need to face the facts, unpalatable as it may seem, that we are relatively inactive, we eat too much and much of what we eat is the wrong type of food. To attempt to imply that it is otherwise is disingenuous. The fact that we are surrounded by the “wrong food” is because powerful vested interests ensure that we are. However, it’s also there because we buy it: but we do have a choice. Surely, this is the crux of the issue, we keep making the wrong (but easy) choices and then having made those choices we look for scientific justification for the fact that we lack self-discipline.
    I thought the programme was based on poor science and was effectively providing another excuse for us to perpetuate our inability to live more healthily. There was a time when I’d have said that it’s not what I expect from the BBC. Sadly, today it is precisely what I do expect from our once-respected broadcaster.

    • You put it in a nutshell. My suspicions were first aroused within a couple of minutes when the first researcher started talking about “set point”: how he couldn’t put on weight because he had some genetically determined set point of weight that he couldn’t overcome. And by implication, that very fat people are victims of a gargantuan set point. This theory has been debunked for years. Once more, it only requires a moment’s thought to realise that set points genetically determined must only have begun to work in the last 50 years. Right.

      I’m not as pessimistic about the BBC as you are, though!

  4. I think some very valid points have been made above concerning the main causes of fat(ness) in our modern society. My main issue with conclusions drawn by the programme relate to the study on identical twins and in particular, where both twins were not the same weight, the reasons put forward for this. I’m no scientist, but to me the whole genetically based argument was fallacious. To suggest that identical twins should weigh the same is as misconceived as saying that two new cars, same make/model/engine size, should deliver the same fuel consumption figures. Yes, the cars should be capable of delivering the same mpg, but fundamental factors such as terrain, loading and the way the vehicle is driven must be taken into account as these will dramatically affect fuel consumption. Likewise, when making comparisons with humans, a person’s exercise regimen (if any), their non exercise activity rates and their calorie consumption are all key factors that must be considered when trying to explain why they weigh more or less than their identical sibling. If these factors were taken into account, I think it is misleading for this not to have been explained in the programme. If these factors were not taken into account, I think the conclusions drawn are just plain wrong and dangerous.

    • The twins argument is very much consistent with the increasing tendency towards genetic determinism. The underlying assumption is that if two individuals have identical genomes, they must be identical in everything. In extreme cases this argument goes so far as to imply that even responses to environmental factors must also be equivalent, such that twins almost by definition have the same environment if they are in that environment together. The only differences between identical twins that are allowed in this model are those that flow from studies of identical twins reared separately. If there were reared together, then they had identical environmental experiences because their responses to their environment were themselves determined by their genes. This is part of a general move towards determinist models of human behaviour that I’ve commented on at length in other posts on this blog.

  5. Just wanted to add that I have had a gastric bypass and my brain is the same! I would still choose the “wrong” food if I could. At first I could eat very little food, of any type. I lost weight rapidly. As my body recovered from surgery I could eat more and I can now eat a small adult meal.Too much sweet food makes me feel nauseous so I don’t eat it. Unhealthy, fatty food also makes me feel ill, so I avoid it. I have lost 8.5 stone in 14 months and feel good. I am worried however, that over time I will be able to eat more and more of the sweet and fatty foods as my body recovers further from the surgery and I will be back to square one.

    • Thanks for commenting, Karen. It’s great to hear from somebody who has real-life experience of the issues. I’m very pleased indeed to hear about your success, but I think you’re right to wonder about the longer-term prospects. I’m entirely convinced personally that this is about diet (not eating less overall, but eating better, and cutting out the “non-foods” of fast food, ready meals, sugar laden drinks, and confectionery, etc.) and the balance of food intake with activity. I really don’t think there’s a better guide to this than Michael Pollan. Read his book, “In Defence of Food” – it’ll be the best 7 quid you ever spend!

  6. Thanks for all your comments above. I currently have a family member who has no memory retention due to a cyst operation and we think she has Hypothamus disorder.
    As a result her weight managment is quiet franky non exisitance(Effectivly outsourced to her husband) she has gone from a normal 14 stone to 21 stone and rising (Over 2 years). This program was very intertesting in that it stated that a Gystric bypass operation would re-teach the brain and would reduce portion size which in tern could reduce her weight and therefore make her mobile agiain (As she is pretty much wheel chair bound due to jionts failing). I guess I am after advise on what the best thing to do is as the NHS have not been the best. I would very much apprectate any assistance or guidence on offer.

    Many Thanks

  7. I have just watched the whole programme hoping for some real insight but instead found it went down the typical reductionist argument resulting in the main hope being in pills or operations. As you say, the ‘scientific’ hormone argument doesn’t explain why there was never an obesity epidemic before, when presumably we had these hormones then! I noticed that the food that was branded as on the bad side and fatty was often highly carbohydrate/sugar-rich rather than fatty. Could it be that we are now eating more refined carbohydrate and sugars than we have ever before, which we are not adapted to, and therefore our insulin levels in our blood are going crazy, which causes us to lay down fat and makes us prone to diabetes etc.??
    I wonder why this wasn’t explored in the programme??

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  9. This program was shown here in Australia recently, on UKTV. I recorded it and watched last night.

    My reaction to the program prompted me to do a bit of Googling, which led me to this excellent article. It saved me from having to write a rant 🙂

    Would have been nice if they had done the before/after hormone stuff on the lady who had the surgery. I’d also be interested to see if they have investigated is the same brain activity changes can be produced via placebo effect (e.g. pretending to operate on someone).

    Hormones, genes, big bones, nature v nurture is all lovely and fluffy and helps us avoid responsiblity. Which is what we’re all about these days isn’t it?

    Thanks for posting this Mr “Gotta-Job”

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