How To Lose Weight. It’s Simple, But it’s Not Easy.

Apparently there’s an obesity epidemic, and it’s because naughty restaurants and “the food industry” are trying to overfeed us as part of a conspiracy to, um… something. And I think everyone knows, deep down, that this is theory is nonsense. Beating up the “food industry” is easier than something that might work, and won’t cost anyone any votes, and may even generate extra “sin taxes” on fat and sugary foods, which is why it’s so politically attractive. But it’s mainly a “something must be done, this is something, so let’s do it” policy.

Obesity, defined as a Body mass index (BMI) of over 30. For my part, I tried the NHS’s Body Mass Index calculator, Male, 41, 6’3″ and 16 st 7lbs which gives me a BMI of 28.7 or overweight, borderline obese. Which is odd, because I still fit into trousers I bought when I was a 21 year old soldier, and right now, I train 5 nights a week. BMI is clearly a deeply flawed measure, from when people existed on severely calorie constrained diets during a major war. Waist to height ratio is probably better.

Nevertheless, BMI statistics inform public policy. Epidemic? About a third of kids are “overweight” or obese, but it’s not rising much, and in any case, being overweight (as opposed to obese) isn’t all that unhealthy. Obesity? It’s not an epidemic.

So what’s causing us to get a bit fatter? Some of it is better nutrition. We’re not just fatter, we’re also more muscular. So, is it about portion size? Possibly, but people don’t eat out often enough for Restaurant portion sizes to be a cause of obesity. People who eat out more are slimmer than those who don’t, because obesity is negatively correlated with income, and overall calorific intake is falling in developed countries. Most people have responded to a sedentary lifestyle by eating less, despite having access to more-or-less limitless calories.

So why do some people eat the right amount of food without thinking about it, and some don’t? Education about how much food kids need will help more than regulating restaurant portion sizes. There is a cultural stigma about wasting food – telling kids to “eat everything on their plate” in a world where food isn’t scarce doesn’t help, and this cultural tick is more common in working-class communities where the folk-memory of scarcity is closer. Kids so raised are more likely to become obese.

There is some evidence that refined foods, white bread for example, is more ‘obesegenic’ than wholemeal. This is because white bread is easier to digest, meaning the starch is broken down quicker into sugars in the gut, leading to a spike in blood sugar, leading to a burst of insulin, then the feelings of hunger caused by the subsequent shortage of sugar in the blood. Less refined foods take longer to break down, meaning you feel fuller for longer. Different sugars are also differently Obesegenic. “Sugar”, whether from cane or beet, is sucrose, a molecule composed of two monosacharides: a glucose and a fructose molecule. This gets split into its component parts. Glucose goes into the blood, where it’s immediately available for metabolism, but Fructose heads to the liver, where it combines with fatty acids to form triglycerides, the main component of body fat. This is why the ‘high fructose corn syrup’ that pollutes so much American food is thought to be especially bad for you. A can of Coca Cola in the USA which is sweetened with Fructose might be more obesegenic than Coca Cola in Europe, which is sweetened with sucrose. The European recipe is closer to Coca Cola’s original 1886 formula (everything except the cocaine, alas…), but doesn’t benefit from the US subsidies to Corn farmers. It’s generally considered to taste better as sucrose is slightly less sweet than Fructose. None of this Fructophobia is settled science. Fructose is the ‘Fruit sugar’ and in small quantities is almost certainly harmless, and there seems to be no one factor driving the west’s expanding waistlines. But it seems reasonable guidance to eat less refined sugar and starch, and keep away from Fructose where possible, except in fruit.

Will “sugar taxes” have any effect on obesity? No, of course not. People can always find a few pence extra for a can of pop if they want one. The Government needs taxes, and this pigouvian tax is probably harmless enough. It might keep the puritans at bay for a bit (unlikely…) But it’s no solution to obesity.

NOT the reason some people are chubby

Is it exercise? We are more sedentary these days. School sports fields have been sold off and kids are forced to sit still for hours a day, and aren’t allowed to play outside as much. This has been improving of late. The “daily mile” looks to me to be an excellent, cheap and simple initiative which gets kids outside every day, and builds a habit of exercise. Which means it will probably be unpopular with the same people who hate cycle lanes, and be binned. People used to have manual jobs, and obesity has been correlated with an increase in office work. Even the invention of the TV remote control means you get up off the sofa to change the channel less often. Less movement, even to change the TV means fewer calories burned going about a daily life. Things like “active transport” cycling and walking work, work. Countries where a large number of people cycle regularly for transport are less obese than countries like the UK where people protest against cycle lanes. Cycling is excellent for keeping the weight off. (It also solves congestion, halt the removal of local services, and keeps the high street busy, raises house-prices, and makes people happier and yet, in the UK, is routinely opposed with quite surprising viciousness, despite cycle lanes also being the state expenditure with the highest return on investment).

But up to three quarters of your daily calorific expenditure is your basal metabolic rate, which the body can adjust when food is scarce. This means if you restrict your intake, or increase your expenditure (ie when you’re dieting and pumping the stairmaster) your body often responds by slowing your basal metabolic rate. Worse, under these conditions, the body often preferentially metabolises muscle to cover the calorific deficit. So burning more and eating less, it’s possible you feel miserable, get weaker and don’t really lose much fat. Worse, your body still craves high calorie food, so when you do fall off the wagon, you fall really hard, and your body stores all that excess midnight ice-cream in the form of fat. A slim person’s body will not process the fat in the same way, at least not at first. This is why some people can eat all they like, and not get fat. Such people crave high calorie food less, and their body doesn’t put their occasional binges straight onto their arses. What you eat matters less than how much; and how much you eat is not very well mediated by will power.

Fat is not therefore a moral issue.

Most people find a weight, and their body sticks to it. Being a bit pudgier as you get older, especially if you remain active, isn’t a problem. Indeed being slightly overweight is healthier than being slightly underweight. But obesity is a fundamental breakdown in the regulation of the body’s energy and storage system. You get stuck at a sub optimal equilibrium, and it’s very, very hard to get out, because anything you do to get your body to shrink its stores is resisted, hard, by some pretty ancient pathways that are not yet well understood.

So, what to do?

No-one really knows, and it’s probably different for everyone. There are almost  no levers the Government can pull beyond declare war and introduce rationing and military training for everyone, for a decade: that could lead to a major fall in obesity, but I regard a pile of corpses as a significant downside of this policy.

It’s clear that drastic calorie reduction works. It’s simple thermodynamics. But to restrict calories sufficiently is also beyond the willpower of most humans. A diet that means you’re hungry all the time simply isn’t going to work for most people. It’s possible to exercise regularly and lose weight. I’ve seen soldiers going through basic training loose a lot of weight, but they’re being told to ‘hurry up’ loudly and often, by very scary people, for 16 hours a day. Few people have the time or the inclination to exercise sufficiently to achieve this sort of weight loss. As you get older, your risk of injury rises, especially if you’ve not worked out for a while and suddenly stopping an exercise program may lead to weight gain. If you’re losing weight due to exercise, it’s not the extra calories burned during exercise that are doing the heavy lifting. Young men joining the army probably stop drinking so much too. So it’s clear that lifestyle changes make a difference. But it’s a higher basal metabolic rate that’s really doing the work.

So, how do we hack into this system?

The rise in obesity came not just with changes to diet or access to more calories. People’s diets have improved since the 1940s and we’re eating fewer calories than we did back in the 1970s. It is also correlated with a reduction in the amount and quality of sleep. Total hours slept per night has fallen steadily since the 19th century, there are more disturbances, and more screens pumping out blue light, which especially interferes with sleep. And when you’re sleep deprived, as most of us are, most of the time, your body produces less Leptin and more Ghrelin.

These hormones control your feelings of hunger and satiation respectively. It’s complicated. Obese people often have more Leptin in their system than normal weight people, which is not what you’d expect, but they’re resistant to its satiating effects. So it’s clear, obesity is caused by a breakdown in the body’s homeostatic mechanism regulating fat storage, and equally clear it’s not fully understood yet.

There are more feedback loops, with which the rolly-poly must wrestle: obesity aggravates obstructive sleep apnea, snoring that wakes you up, further disrupting your sleep, and preventing you achieving the deepest levels of sleep. A vicious circle: when you’re sleep deprived, you want to eat more and do less. Your body is stressed and conditions itself to lay down fat. Your basal metabolic rate falls. If these conditions last, then your body lays down a lot of fat, and conditions itself to stay that way. And it resists attempts to break into this cycle.

Then there’s the research into the gut microbiome. If we still haven’t got to grips with the body’s homeostatic mechanism regulating fat storage, we’ve little hope of understanding this system with involves millions of species of Bacteria, and the prevalence in the gut appears to depend on which things like whether you were born naturally or surgically, whether you were fed by breast or formula. Quite a lot of digestion happens because of your Gut bacteria. So eating probiotic yoghurt, or shoving someone else’s poo up your fundiment (a medical procedure known as a ‘fecal matter transplant’) appears to have an effect, but this can go both ways. We don’t even know whether gut disbiota is a cause, or an effect of obesity.

This is why it’s so hard to lose weight. Diet alone won’t do it. Exercise alone won’t do it. Sleep alone won’t do it. Gut microbiota alone won’t do it. But if you sleep well every night, and exercise every day, you might find yourself eating less and doing more, without thinking about it. And it appears that your gut microbiome may change as a result of your efforts. To do this successfully probably involves less alcohol consumption, a substance which also disrupts sleep, doesn’t exactly make you want to hit the gym, interferes with the bacteria in your gut, and interferes with the mechanisms that make you feel full. A rigorous and abstemious regime, kept up for months, you may find yourself losing weight as your body changes the equilibrium it’s seeking to maintain. You can’t lose weight if you’re drinking alcohol, smoking, binge watching netflix and staggering bleary eyed to the office every morning, and cracking open the wine every evening.

This is the problem. Obesity is incredibly complicated, and the sugar tax, portion-size restrictions and so forth will have no measurable effect, and who knows what the bansturbators will want to tax next. An obese individual just needs to sleep longer, cycle to work, not stare at a screen before bed, cut out caffeine late in the day, cut down the booze, do more, harder exercise near-daily and not fall off the wagon too often, and they need to keep this regime up for so for months and months and months. I think everyone knows, deep down, what to do. Ultimately the only way to do it is to change lifestyles completely. Losing weight isn’t rocket science, it just requires an iron discipline few of us have. After all, one of things you’ll end up cutting out, is socialising with all your friends, who’re probably still in the pub.

Losing weight – People’s girth isn’t a proper matter for Government because only an individual can decide their priorities. What Government can do (and is doing, to be fair) is fund research into what might actually work something we don’t yet know, and then telling people about it. In the meantime, cut down the booze, get a good night’s sleep, and when you’re rested, think about the diet and exercise.

2 replies
  1. Luke
    Luke says:

    Late to this, but there’s another problem- we burn calories (a) being alive,(b) conscious exercise whether gym/sport or stuff like walking/cycling to work, and (c) fidgeting.

    Base rate is measurable if not controllable in the short term, being roughly related to size and muscle mass. Exercise is in theory controllable and fairly measurable. But fidgeting is difficult to measure and impossible to control. It’s why some people stay thin despite their apparently poor diet/exercise levels. (Think kids hyper on sugar.)

    If you cut calories and maintain exercise levels, you fidget less. Your body is telling you to take it easy – you are in calory deficit. Hence the phenomenon of diets that work for a while followied by “slowing metabolism”. You may be maintaining your *conscious* exercise level, but you’re not *moving* as much. Say you know this, and you up the (conscious) exercise. Your body just feels more knackered, and and drops the (unconscious) fidgeting still further.

  2. Jackart
    Jackart says:

    Base metabolism responds to exercise. If you’re working out, your basal metabolism is working harder, and you’re burning more calories while you’re sitting on the sofa. It’s not got much to do with figiting.


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