If I was a detective looking for the mastermind behind weight gain, I would be foolish to ignore the stack of evidence that points the finger squarely in the direction of the brain being the main culprit, but is the brain really the villain in this plot?
How has the brain ended up a suspect?
Have you ever thought about what motivates us to eat food? Why we are driven to eat certain foods more than others?
It comes down to an economical equation which can be found throughout nature.
Stephan Guyenet, PhD an expert in the area of neuroscience and obesity, he coined the term “optimal foraging equation” which can be traced back to the beginning of human history.
In simple terms we are motivated to eat food which brings us the greatest amount of benefit (Calories) for the least effort (energy expended and time). In the wild, hunting for food that is quick and easy to catch and yielded high amounts of energy is ideal for survival. In nature the best gatherers of food are the best survivors and therefore the best reproducers…the end goal.
This is where the brain starts to come in to the scene. For animals including us to know which foods are nutrient dense there needs to be a system for it and there is.
When we eat a food, nerve endings in the lining of our upper small intestine record and measure the concentration of nutrients including protein, starch, fats, salt, sugars and glutamate (which gives a meaty umami flavour like in soy sauce).
This report is then sent on via the vagus nerve to the brain.
Once at the brain, the signal triggers dopamine to be released.
Dopamine is a neurotransmitter linked to the reward system and is released to motivate us to do the behaviour again. A modern-day example is getting a “like” on Instagram or Facebook, when you get one it makes you feel good and motivates you to post again to get that similar feeling.
Our brain releases a variable amount of dopamine based on the nutrient concentration of the food reported.
This means the denser a food is in nutrients, the more dopamine is released, the more motivated we are to do it again.
In practical terms this means when we eat pizza for example, the report from the intestine tells the brain this is a brilliant source of nutrients so we should remember it for next time.
The brain stores information such as smell, site and taste so whenever it comes across it again it knows to eat it. This is where cravings come from, something I will speak about in more detail going forward.
Our brains want us to eat calorific foods, our brains don’t want us to lose weight, our brain doesn’t care what we look like on holiday, our brain is set up for survival.
Times have evolved but our brains have not
Being motivated to eat calorific foods is a brilliant survival tool but unfortunately, we don’t live in a world where we need to survive like we used to.
Our brains still get excited like a puppy when we come across pizza, cakes and all the tasty food because to our brains, it means we have hit the jackpot and can now survive for a further few days.
The differences between the times of our ancestors and now are stark.
Our ancestors would have had limited availability of highly energy dense foods and even when they found them, they would have expended a lot of energy catching them over many days, sometimes even weeks.
Nowadays food is easily accessed in shops, restaurants and takeaways.
It doesn’t take any energy whatsoever to gather, I mean nowadays people are even too lazy to even go to the shops.
Food is more energy dense than ever, with more added fats, sugars etc. than at any point in our history. Added fat in foods has more than doubled since the 1930’s. In the US, added sugar consumption was 5 lb per person per year 200 years ago, it now stands at 100 lb per person per year.
It is hard to say no to the foods we love because our brain is programmed to love them, meaning we are motivated to eat them. To say no requires motivation, it requires a bigger why, it requires us to be switched on when we make food choices.
Although the brain is what drives us to eat Calorific foods in this instance I feel it is unfair to blame the brain as after all, it is doing it’s job of keeping you alive, driving you to get the energy you require.
“Focus on the things we can change”
We can’t change how our brains are wired but we can change the environment.
Perhaps there lies the real villain.
Ps: If you are looking for a great book to read around this area I can’t recommend The Hungry Brain enough.