If weight were a matter of calories in and calories out, we’d all be the weight we choose. We all know the ‘eat less’ principle, and yet, somehow it isn’t. Perhaps, therefore it’s time to consider the problem through an alternative lens.
Hunger is a motivated state of mind. We all feel hungry before dinner and full after a meal, but those moments are the tip of the iceberg. Hunger is a process that’s always present, always running in the background, only occasionally rising into our consciousness. It’s more like a mood.
How it all works
The hunger mood is hard to control, precisely because it operates outside of our consciousness. This might be why obesity is such an intractable problem. The hunger mood is controlled by the brain stem. The part most responsible for regulating hunger and other basic motivated states is the hypothalamus and it sits at the bottom of your brain.
It has sensors that detect levels of fat, protein and glucose, as well as blood pressure and temperature. The hypothalamus gathers this data and combines it with sensory signals that percolate in through other systems in the brain fullness in the gut, the feel and taste and smell of food, the sight of food, even the time of day and other surrounding circumstances.
Given all this data, the neural circuits train up on our dietary habits. That’s why we get hungry at certain times of the day, not because of an empty stomach, but because of a sophisticated neural processor that anticipates the need for more nutrition. If you skip a meal, at first you feel hungry, but then you begin to feel less hungry as that accustomed mealtime passes by. That’s also why we get full at the end of a meal.
Psychological fullness is a feeling of sufficiency that comes from a much more complex computation. The hypothalamus in effect says: ‘You’ve just eaten. We know that in about two hours after having eaten, the level of protein and fat in the blood will rise. Therefore, in anticipation, the brain switches off the feeling of hunger. The system learns, anticipates and regulates. It operates in the background.
Most doctors and healthcare professionals think about weight from the perspective of chemistry. It’s calories in versus calories out. Different schools of thought suggest that all calories are equivalent, or that fat calories are especially bad, or that carbohydrate calories are particularly to be avoided. These approaches focus on the way that calories are digested and deployed in the body. They ignore psychology.
A ‘properly’ controlled study, forces participants to consume a set amount, of calories, therefore screening out the influence of autonomous human behaviour. And for all that has been learned from this mainstream medical approach, the advice is failing us. More than two-thirds of the US population is overweight. More than one-third is obese.
In that theory, if you cut out enough carbs, your body switches from using glucose to using ketones as the main energy-transporting molecule in the blood. By using ketones, the body begins to draw on its fat reserves. Moreover, by reducing blood sugar, the body reduces insulin, the main hormone that promotes the deposition of fat in the body. Less carbs, less fat.
A recent study monitored two groups of people. For six days, one group ate low-carb, the other low-fat. Both were strictly forced to eat the same number of calories. The result was the low-fat group lost most weight. The theory and the experiments emphasise how calories are deployed in the body, instead of emphasising the motivated state of hunger.
It is now well-established that a high-carbohydrate diet increases your hunger. A low-carb diet removes that stimulant. The evidence suggests that a low-carb diet doesn’t make you lose weight, because of its effect on your energy utilisation. It makes you lose weight because you eat less.
Because that hunger state runs mostly beneath consciousness, it’s easy to misattribute the result. But in the end, if we follow the death-carb diet to its conclusion, we can’t help noticing the effect on our appetite. Extremely obese people reach a point where they’re always hungry, never full as the brain isn’t satisfied.
In some ways, the hunger system is like the breathing system. The brain has an unconscious mechanism that regulates breathing. The intellectual, conscious mind is not good at these matters of regulating the internal environment. It’s better to leave the job as much as possible to the dedicated systems that evolved to do it.
What you can do with your conscious mind is to set the general parameters. Put yourself in a place where your automatic systems can operate correctly. Don’t micromanage your brain stem by counting every calorie. You might be surprised at how well your health self-regulates.