Don’t Muck Around with Biology! A Million Years of Evolution is Hard to Beat

The common reasons that people gain weight are attributed to portion control, lack of exercise, stress, emotional eating, genes, fast food, snacking, childhood trauma…according to psychologist Dr Douglas Lisle, this is a whole lot of rubbish.

It’s actually much more interesting and confusing than that. People who gain weight are not necessarily lacking will power or any more “bad” in their eating than the naturally thin people (who comprise about 15 % of the population BTW).

To work out why, we’ll start with Dr Lisle’s Universal Law of Satiety: “Animals eating to full satisfaction (satiety) in their natural habitat will, over time, eat neither too much nor too little for optimum health”.

Humans, like all animals, have multiple “satiation” mechanisms that control all our bodily functions: we naturally breath the right amount; we naturally drink the right amount of water and sleep the right amount. These critical mechanisms comprise whole banks of sensors and regulators in the body and brain. (I’m paraphrasing Dr Lisle here)

So why are humans (and cats and dogs) the only animals that have problems with weight gain and the subsequent health problems?

Humans have manipulated natural foods so they’re no longer recognisable to the important sensors in our bodies, sensors that are located all over our bodies – in our mouths, in our stomachs and our intestines. They’re controlled in the hypothalamus, a part of our brain that keeps our bodies in a stable, constant condition. The neurons in the hypothalamus are constantly being bombarded with signals from the internal and external environment including body temperature, hunger, feelings of being full after eating, blood pressure and levels of hormones in the circulation and more.

The hypothalamus is a pretty amazing bit of kit. Not only does it analyse data over time by logging trends (eg whether you’re losing weight or gaining weight) but it also analyses data in real time including constantly monitoring is food intake.

There’s two critical things happening that work together to keep our food intake perfectly balanced: one is “stretch reception” and the other is “nutrient receptors”.

Sensors and neurons in the alimentary canal and stomach help the brain analyse how much the stomach is distending and stretching to accommodate what you’ve swallowed AND exactly what the food is nutritionally.

If you eat a pile of lettuce it will know that, and if you’ve eaten a pile of potatoes it registers that differently. The nutrient receptors measure the macro-nutrients (fibre, water, carbohydrates and protein). So the brain knows to keep you wanting more calories, or if you’ve got enough of what you need.

Imagine you’ve taken a bite of food. You roll it round your mouth. While you’re experiencing the food with your conscious senses of taste, feel and smell, another part of the brain is busy being a chemist; carefully analysing the chemical make up of the food.

The brain estimates volume AND calories. Animal systems are designed to automatically register the “calorie density” of the food you’ve eaten. Our body estimates the calories as we’re eating them, using volume and nutrient. This macro-nutrient analysis works out what the food contains and if it’s the right balance for our needs.

Our bodies are designed to eat foods in combination, where we can get nutrient density.

So how does this work with controlling weight gain?

It comes down to how many different types of fat in the food you eat and how many fat detecting receptors you have. Turns out, that having more fat detecting nutrient receptors is good. That’s what many naturally skinny people have. For the 85 per cent of us who have fewer fat detecting nutrient receptors, well that’s a problem.

It basically comes down to whether your nutrient receptors can catalogue or count the elements of fat in your digestive system. If the fat isn’t being registered, the brain can’t message that we’ve had enough to eat.

If the food is really rich and fat dense (with fat coming from several sources, such as in junk food) the fat receptors get overwhelmed, throw their hands in the air and walk off and don’t turn off your appetite. Your nervous system doesn’t know you’ve already eaten enough and it’s how we break the Law of Satiety and create systematic over eating.

The receptors in our digestive system are getting fooled! They weren’t designed to eat pure fat. If you put more fat in the system than it’s designed to eat, then lots is going to get though without being counted.

Now, down the nitty gritty. Why does the stomach get fooled? Because we process food and cause fibre deficiency and fibre damage. The registration systems in our stomach get muddled up and hate it when the fibre goes through too quickly and they can’t get a good look at it to catalogue it properly. Because not only does the stomach measure the chemicals (nutrients) it also measures the stretch, and importantly, the time the food stays in the stomach.

Fibre hangs around longer.

Processed foods go through more quickly. (For instance, our body will register a ground up apple as being of lower nutritional value than a raw apple). Fibre has zero calories. Once we grind it up and make apple sauce we alter the fibre and we digest it more efficiently and this effects the calorific density of the food.

Or….put it another way. Your body is designed to eat natural foodstuffs.

Once we start to muck around with food, the calories and the chemicals get all mixed up.

So that’s why calorie counting became a thing since the 1950s (it didn’t exist before that)!

And why we should eat carbs – in their unprocessed state!

Two excellent presentations on calorie density

Dr Douglas Lisle: YOUTUBE: https://www.youtube.com/watch?v=Z96ThwPd4ak&t=6661s

Jeffrey Novich: https://www.youtube.com/watch?v=0CdwWliv7Hg