Our ‘Ancient Brain’
&
The Weight-Management Dilemma

Over the past 30 years or so, there have been huge advances in Neuroscience (the study of the brain and nervous system) - which has entirely overturned many commonly held theories regarding the relationships between how our brain functions and regulates the body and the foods we consume.

This new-found clarity has been especially realised through pioneering scientific studies and incredible technological advances, allowing us to transform our understanding of how our brains and nervous systems work. During your programme, many of these nutritional and physiological discoveries will be discussed. Unfortunately, most of these are only slowly filtering through, and are hardly reaching the general public’s awareness.

As is almost always the case regarding scientific facts and mainstream beliefs, popular culture lags considerably behind the scientific community. For example, smoking was scientifically proven to cause lung cancer in the 1930’s. Governments did not formally accept this until the 1960’s, cigarette packets did not require ‘appropriate’ health warnings until the 1980’s, and smoking in enclosed public spaces was not banned in the UK until 2007.

It goes without saying that the vast majority of mainstream weight loss ‘diets’, especially those which advocate severely restricting calorie intake or specific macronutrients (including nutritional and weight management advice offered through the popular media), do not take the latest advances in nutritional science into account - and thus do not work long-term. A fact supported by today’s appalling weight loss statistics.

Perhaps some of the most revealing neuroscience-based discoveries regarding nutrition and weight management - in particular, how we are drawn to specific types of foods and how the body literally ‘fights back’ against attempts to lose weight - have been brought about by understanding that different parts of our brains, which serve different functions, have developed at vastly different times during our evolution.

There are essentially three separate parts of our brain - although this is an extremely over-simplified description of what is an astonishingly complex organ.

The ‘reptilian’ brain is the oldest part, which controls our most basic functions such as breathing, balance, heart rate, and blood pressure.

The ‘limbic’ brain, which developed much later, is associated with behaviours that produce agreeable or disagreeable experiences and is responsible for our emotions. It is the core of the pleasure/reward system, and the seat of beliefs and value judgements that unconsciously strongly influence our behaviours.

The ‘neocortex/cerebral cortex’ is the most recent part of the brain to have evolved, and includes the prefrontal cortex - which is responsible for rational thought, consciousness, language, self-control, awareness, and deals with concepts such as the future and morality.

These three parts of the brain do not operate independently but are connected by a network of neural pathways through which they influence one another. The neural connections from the limbic system to the cortex are especially well developed, but those from the cortex back to the limbic system are less so. This is very important, as it essentially means that the emotionally driven part of our brain - which governs our actions on a subconscious level - can ‘shout much louder’ than the rational part of our brain, which is supposed to keep these emotional reactions in check.

This profoundly affects how our emotional relationships with food can control our cravings and eating behaviours - especially when we consider where we have come from - our ancient ancestors.

Our ancient ancestors were hunter-gatherers living on wild plants and animals in small isolated tribes. For them, life was really, really tough. Food was perpetually scarce, and they never knew when their next meal would be. Hunting involved tracking wild animals across inhospitable terrain, sometimes for days, and gathering involved walking for miles and miles each day to find ripe fruit, edible plants, nuts and seeds. And of course, wild animals were hunting them too.

So to survive and thrive, they evolved with biological systems specifically adapted for those particular environmental conditions - to that ancestral hunter-gatherer lifestyle, in that inhospitable and unpredictable environment - motivated, for their very survival, by…

Pleasure Seeking - This causes the release of dopamine (the pleasure hormone) into the area of the brain called the nucleus accumbens - which is part of the pleasure/reward pathway in the ancient limbic brain.

Energy Conservation - If you don’t know when your next meal is going to be, you want to be as efficient with your energy as possible.

Pain Avoidance - Making sure you are not eaten by anything or injured. Essentially ensuring your genes can be passed on to the next generation and beyond.

Dopamine Resistance

But here is the big problem. The limbic brain, the core of the pleasure/reward system, which can shout much louder than our brain's rational, self-control centre (the cortex), is still perfectly adapted to that inhospitable and unpredictable ancient environment. But this is not where we live today.

Just imagine you are back with that ancient tribe. Starving and walking miles and miles to find food. Suddenly, you come across a pear orchard, and the pears are perfectly ripe. Our bodies - preferentially fuelled by carbohydrates and fats -  instinctively know that sweet foods and fatty foods contain a lot of calories. Calories that we have evolved to crave - to fuel us, to keep walking and hunting covering those miles and miles, and to sustain us in times of famine.

We also know that every other living creature is in the same situation as us, and that these pears are not going to be on the tree for long. If we don’t eat them, something else will. So you eat as many as you possibly can, there and then.

And as you do, dopamine, that pleasure hormone, is released and triggers a response on receptors in the brain, reinforcing that this is good for your survival - and a neural pathway in your memory bank is laid so that you remember where this orchard is for the future. Eating as much as you can there and then also satisfies that Energy Conservation rule - why expend energy carrying the food elsewhere to eat it, or by going away and returning tomorrow? That doesn’t make sense - those pears might not be here tomorrow.

And of course, the same response will happen when you come across fatty foods which are also high in calories, such as nuts, seeds, and any meat that you catch and kill. The same can be said for salt too - which was vital for replacing electrolytes lost during all that running and walking.

If we fast forward to today, the neocortex/cerebral cortex, the most recent (creative and cognitive) parts of our brains to evolve, are now able to design, manufacture and market foods so unbelievably sweet, and so unbelievably fatty, and containing so much salt, that nothing in nature has ever existed like this before.

But the limbic brain and all of the associated pleasure/reward systems - which control our hunger, mood, and behaviours - are still perfectly adapted for the days of hostility, food unpredictability, and famine. And so we are instinctively drawn to those foods because they are sweet, fatty, salty, and calorific - which satisfies those ancient rules for Pleasure Seeking and Energy Conservation, which still control us now.

However, due to the process of sensory compensation and regulation - one of the ways the body satisfies that third rule, Pain Avoidance - the body instinctively down-regulates any overpowering stimulus to protect itself and stop those sensors from getting damaged.

This can be seen in drug addiction. Cocaine, for example, is a stimulant way more powerful than anything that actually exists in nature. When it's consumed, it produces a dopamine rush so intense that it completely overwhelms the pleasure/reward system.

And here’s the important part. The brain thinks, wow, that was fantastic. It’s obviously good for me, for my survival, because dopamine was produced…. remember the dopamine produced with the pears? I must remember to do that again because it is obviously good for my survival… just like remembering where that orchard was. And what a great way to get that much dopamine without expending any energy at all.

You see, Pleasure Seeking and Energy Conservation is good for the survival of the genes.

But as we take the cocaine again and again, our brain also thinks, wow, this is some crazy hit - but if I continue like this, it will burn out my pleasure sensors completely - and I need to feel pleasure. So the body down-regulates the dopamine receptors, and the effects of the cocaine hits are reduced, and over time, we get used to them.

So then, in order to get that same hit, we need to take more and more. And our sensors are downregulated more and more. Eventually, because our dopamine receptors are so downregulated, nothing we eat, drink, or take can give us the consistent dopamine levels that our body needs.

Until - like most addicts - we take more, not to get high, but just to feel normal.

The big problem is that our brains cannot tell the difference between an extreme dopamine rush caused by cocaine or an extreme dopamine rush caused by these highly processed foods… foods that are so unbelievably sweet, and so unbelievably fatty, and contain so much salt, that nothing in nature has ever existed like this before. These foods cause the very same dopamine receptor downregulation as cocaine.

So, exactly like the cocaine addict, because our dopamine receptors are so downregulated, a pear simply can’t give us the consistent dopamine levels that we need - and so we seek out more and more of these overly sweet, fatty, and salty foods, just to try and feel normal.

Our Pleasure Seeking, Energy Conservation, and Pain Avoidance systems, which have taken millions of years to evolve for our survival, have been hijacked - and are now unwittingly driving us to eat foods that cause weight gain, obesity, and numerous life-threatening health conditions.

Leptin Resistance

Another crucial area within the Limbic brain is the Hypothalamus, which regulates hunger, thirst, the autonomic nervous system, and much more. It also has areas that are particularly involved in regulating eating - receptors for the hormone leptin.

Leptin is released by fat cells. The more fat you have, the more leptin you produce. This wonderful feedback mechanism tells your brain, via your hypothalamus, that you have enough fuel on board. This results in two outcomes - your brain stops you eating, and it tells your body to start moving. This feedback loop ensures that all mammals stay a healthy, active weight. Leptin, therefore, is the hormone that keeps you thin.

In the same way that type 2 diabetes is a result of insulin resistance - not of lack of insulin - it has been discovered that there is also a widespread epidemic of leptin resistance in overweight and obese people. The fatter we are, the more leptin our fat produces… but our brains just can’t see it.

The problem with leptin resistance is that there is no arguing with a brain that does not know we are overweight, but thinks we are starving and about to become underweight. The founder of the food addiction programme Bright Line Eating, Dr Susan Peirce Thompson, has coined this ‘insatiable hunger’ - a hunger not satisfied by eating. This, together with dopamine resistance, is why you can have a huge dinner, sit down to watch TV, and before you know it you’re off to the freezer for that tub of Ice cream.

There are three main causes of leptin resistance in the hypothalamus. High levels of inflammation in the body, insulin resistance, and high triglyceride (fat) levels in the blood - all of which shall be covered separately in detail during your programme.

The only way to resolve leptin resistance is to get healthier - through sustainable lifestyle changes - to reduce inflammation, insulin levels, and blood triglycerides.

Willpower.

Willpower - or more precisely, our lack of it - is another example of the ancient part of our brain becoming overwhelmed by circumstances today’s lifestyle presents, which it has not evolved to cope with.

There is a part of the limbic brain known as the Anterior Cingulate Cortex. This is a hub that regulates several endeavours, including; emotional control (not engaging in road rage), task persistence (filling out a spreadsheet accurately), and making decisions (do I respond to that email or put a label on it or bin it?).

This part of the brain also helps us resist temptations - it is the seat of Willpower. Unfortunately, this part of the brain is remarkably sensitive to glucose fluctuations in the blood, and is easily fatigued - its performance starts to dramatically decline after about 15 minutes of extreme activity.

This is why, on a Friday night - after a long day of a long week, when you are stressed, tired, and your blood glucose is low - you suddenly find yourself ordering a pizza. Our ancient brain did not evolve to deal with all of these emotional control, task persistence, and decision-making processes simultaneously, and our Anterior Cingulate Cortex gets burned out - and bang goes your willpower.

Our brains know exactly which foods will pack the biggest punch in terms of calorie density and richness. With the pace of modern life and the availability of hyper-palatable foods, making an ‘in-the-moment’ good decision about food is virtually impossible.

The easiest way to combat our lack of willpower is to make eating healthily a habit that you don’t even think about - an automatic habit like brushing your teeth. This way, when that Friday night comes around, there are no spontaneous decisions to be made.

Planning and preparing your meals in advance, especially immediately after eating dinner the evening before, means that the limbic brain does not actually control your decisions - but that they are made by a different part of the brain, which is very detached and focussed, and not affected by emotions, dopamine, leptin, stress and how tired you are.