Thursday, 24 July 2008

Missing the Point

I was going to leave the issue of appetite alone for a while. Readers of this blog will know that appetite is a recurring theme. I have hit it from several angles over the past few months and by now you should be convinced (or at least have considered), that no amount of calorie restriction is going to get you thin - or keep you thin - if it leaves your appetite unfulfilled. 'Traditional' calorie restriction i.e. the type that does not satisfy your appetite, will eventually result in a lack of energy, fatigue and general unhappiness. It will also affect body composition for the worse.

Hunger, like thirst, is a highly evolved mechanism to signal a requisite action. There is little performance hit when these signals first manifest, but a failure to address either will eventually lead to physical and mental impairment.

There is too little focus on either the precision of these mechanism or how they can go awry. Both scientific research and politicians focus on issues 'downstream' of appetite, which, whilst having obvious value, will do little to resolve the problem of obesity.


It is the scientific community and politicians who have the power to resolve the problem of obesity in the community - but don't hold your breath. Today I read with real dismay a speech by Alan Johnson (Labour MP for West Hull and Hessle) addressed to the Fabian Society. In it he came out with the classic line "Obesity is the product of a simple imbalance between energy intake and energy expenditure".

On the face of it this sounds reasonable. Sadly it is rubbish! Of course, broadly speaking, if we eat more energy than we burn off, then the body will accumulate fat. But what this line of thinking does not address is 'how is it that we can repeatedly eat more calories than we need to sustain ourselves?'.

I mean, if we eat 'more than we need' at breakfast, why doesn't our appetite adjust so that we eat less at lunchtime? It sounds a reasonable proposition doesn't it?

The problem with Johnson's thinking (and it isn't just him, it is endemic throughout the political system, scientific population and general public), is that if you take this logic to its natural conclusion, it makes little sense. So, for example, if we eat 'more than we need' at breakfast, then according to Johnson's logic, even though we have a surplus of energy from breakfast, we may then go on to eat 'more than we need' at lunch, and then we may then go on to eat 'more than we need' at teatime, day in and day out.

When you read it like that - successive over eating sounds frankly odd, and the mere thought gives me stomach ache. It just makes NO sense that we could persist on such a cycle.

Now let us revisit this scenario as I see it. If we eat 'more than we need' at breakfast, our bodies will adjust such that hunger will manifest at a later period than normal - so, we have a late lunch. Or, if we chose to eat at the same time, our appetite is reduced and we eat a smaller lunch. That sounds much more plausible doesn't it?

The Johnson model allows us to eat ourselves in to poor health and a state of immobility. The Asclepius model dovetails in to other evolutionary mechanism - two million years in the making and refining - such as thirst.

Johnson's understanding of overeating makes no more sense than over-drinking (exceptionally rare). What's more, his idea ignores concepts of hunger and appetite.


You could draw any number of further analogies. If you fill a car with petrol, well filling the tank up to the top means you can drive further before the petrol light (hunger) illuminates. Less petrol means the petrol-warning light comes on earlier. If you get to the next petrol station without the petrol light going on, you will have to put less petrol in. It is an idea so simple it maddens me that it is missed.

Alternatively, think of your body's heating system. If you get too cold, your body starts to shiver. If you get too hot you sweat. Your body tries to adjust to maintain homeostasis within a particular range.

Sweating occurs for a given internal temperature that is affected by external heat (climate/weather, clothing, a fire) and internal heat (physical activity). But without changing these factors, you cannot simply chose to 'push' more sweat out.

If you do expose yourself to more heat (such as putting on more clothing), you would not expect your body to shiver. Or, if cold, you would not try to get your body to sweat. Basically , you would not fight these natural mechanisms. You trust that your body will sweat/shiver appropriately as required to sustain your internal temperature within a range.

You have no direct control over these mechanism and would certainly not really want to battle them. So why give advice to battle hunger and appetite?


Politicians are elected to make key decisions about how our society is run. There are a few ticking time bombs out there for them to tackle - the aging population, an increasingly obese population and more importantly the mixture of the two, which will have serious socio-economic implications within the next decade or so.

Politicians need to drive at the root of the problem, but instead seem content to offer weak platitudes (eat less, do more), and throw money at treating sickness rather than preventing its cause. That money comes from tax - but you can only tax a population so far - beyond that, the whole economic model breaks. We are reaching breaking point.

Sadly few seem able to look with fresh eyes at the problem of chronic (Western) disease, obesity and the consequence of trapping people in an infirm state.

People have a right to a dignified old age. Pepole should have health for most of their lives. Sickness should be occasional, NOT chronic. Terminal illness should bring a swift death, but a terminal illness should come after a long life.

Diet is stripping people of the chance of a long and healthy life, and medicine ensures they live long enough to suffer.


Methuselah said...

I think one of the reasons people fundamentally misunderstand the role of appetite in regulating food intake is that they view the issue through the prism of their own experience which usually is that of a normal, relatively high carbohydrate diet. Thus, when stating that people become obese through overeating, they feel they can say this with authority because their experience is one in which hunger is not as well regulated: they become peckish within a few hours of a meal and perhaps have difficulty limiting themselves in the amount of calories they eat. To combat the additional calories they may do more exercise which in turn increases their appetite and invariably leads to more food being eaten.

You talk about death - well in my view it's actually death that will, ironically, bring us to a point where this issue is understood properly. Sometimes there are views or habits which are so entrenched that behaviour and attitude change is out of the question and the only way the world moves on is when the people who hold those views die out.

I know it's a bit off-topic, but I think our attitude to privacy is one such example. Younger generations really don't care about their personal information being used in the digital world if they know they will get something in return. Older folk are vociferously against it. In time the world will forget those views and the myriad applications made possible by a free flow of biometric and other data will come to pass.

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Anonymous said...

You are entirely missing the point on our digestive system.

Our body is built of a variety of complex mechanisms that regulate food intake and digestion. However, this system has evolved of the tens of thousands of years. The bounty of having any food you want at any time that is present in modern society is problematic because the hardware in our bodies has no way of knowing how to deal with this.

To use your stupid car analogy, eating now is like filling your tank of gas and the little light goes on, except in 1940 they replaced gas with rocket-fuel; your engine explodes.

Our bodies haven't changed much, our food has.

Asclepius said...

"The bounty of having any food you want at any time that is present in modern society is problematic because the hardware in our bodies has no way of knowing how to deal with this."

Whilst I will agree that the types of food available have changed (not for the better), your statement above implies an assumption that there was a regular scarcity of food in our ancestral past. There is no evidence for this. Even in winter, as a big game hunter, there is still big game available. In fact a dependence on agriculture is more likely to lead to famine as a single storm could destroy your crop - there is no plan B. As a HG, there is always a plan B because the next meal is walking around somewhere.

The car analogy works perfectly (and I am glad you are fond of it), when used to illustrate hunger. You are right that people have change the 'fuel' they run on and it has been proven to mislead our appetite.

The bottom line is that it is the type of fuel that we eat, rather than the availability of it.

I couldn't agree more with your last statement.

Methuselah said...

Hi - I just posted a meme (just for fun) - pass it on or leave a comment on the post if you have ever got sick of how to answer the question "You're on that funny diet, right?"

Have a good weekend!

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