If you want to learn how to control how you eat we must first understand the mechanics of hunger.
Your appetite is controlled by both your brain and the stomach. The brain being the most powerful so we will start there.
The main gland in the body that is responsible for controlling our feeding habits, it is the Hypothalamus gland. This gland is the subconscious command and control centre for the whole body. It is a gland located in the brain of humans. It can be found between the thalamus and brain stem and is roughly the size of an almond.
How this gland controls our feeding is by sensing the levels of the hormone leptin available to the body.
Leptin is a hormone secreted by the white adipose tissue. It is released when the body has enough fat in storage and the person can stop feeding. Conversely leptin levels are depressed in times of no food or if a person develops leptin resistance.
When leptin is low this is where neuropeptide Y (NPY) kicks in. NPY is the main hunger signal in the brain and must be satisfied before the person stops eating.
Leptin and NPY are on opposite sides of the seesaw. When one is up the other is down. So Leptin is up, NPY is down and we don’t need to feed. NPY is up, Leptin is down and we feed.
Leptin and NPY also differ on the side of the brain that they effect and the food type that influences them. This whole process goes on subconsciously and we are unaware of it the majority of the time. However once we get the hunger signal from the brain it will not go away until it is satisfied no matter how hard we try to fight it.
Let’s take a look at the brain signals measured by the hypothalamus. Learn how they are influenced and what influences they have on us.
First up is Leptin which is the hormone responsible for telling us when we are full. It is closely related to the sympathetic nervous system (fight or flight). Dopamine is the primary neurotransmitter for leptin.
Dopamine levels are increased by consumption of fats. Increased fat intake means, increased levels of leptin being transmitted, This in turn depresses NPY so we stop feeding. Dopamine is made in the body by an amino acid called tyrosine. Tyrosine is found in animal proteins and cheese.
This shows us the important role that fats and proteins have in every day diets.
Carbohydrates are vitally important to the diet also. It is through high carbohydrate intake and an amino acid called tryptophan that the neurotransmitter serotonin is increased.
Serotonin fuels the parasympathetic nervous system (rest and digest). High serotonin depresses NPY giving you a satisfied feeling. Unlike the sympathetic nervous system the parasympathetic nervous system has no direct link to leptin levels.
It is important to keep serotonin levels in check. Low levels can lead to depression in men and women. As well as mood fluctuations for ladies prior to going through their menstrual cycle.
Newly emerging studies have also linked brain histamine levels with food cravings.
When the hypothalamus detects higher neuronal histamine your appetite is depressed. This brain histamine works in the same fashion that leptin works, in that it depresses NPY. However it not only helps with depressing a person’s appetite it is also essential for brain alertness. This could be a reason why antihistamine medication as well as anti-psychotic medications that contain antihistamines cause weight gain.
Calcium plays a vital role in controlling our appetite. It has a direct influence on a brain signal called agouti. Agouti and NPY work on the same principles. They both stimulate the intake of food while also slowing down your metabolism.
It is also well published that when your levels of NPY and agouti are both high it blocks thyroid function. A proper functioning is vital for how quickly the body uses energy. Making proteins and it is also responsible for controlling how sensitive the body is to other hormones.
However high agouti has another nasty little party piece. It amplifies how much leptin is produced by your fat cells. At the same time it blocks the hypothalamus from receiving this leptin signal resulting in leptin resistance. This increases fat storage while inhibiting your ability to breakdown fat.
As dairy is one of the best sources of calcium make sure you get plenty of good quality cheese and yoghurt into your diet. Go for the full fat because as we have seen earlier fat is so important for a healthy body.
I don’t mention milk here because I believe that the pasteurisation and homogenisation ruins the goodness of milk and makes people more likely to develop lactose intolerance. However if you can get good quality organic raw milk and want to drink that I would say go ahead.
How much sunshine we are exposed to also has a dramatic effect on our appetites. It has this effect by inhibiting the level of leptin that the white adipose tissue secretes. Therefore reducing a person’s likelihood of becoming leptin resistant. Also the more sunshine we expose ourselves to means more vitamin D. This will in turn lead to more calcium uptake and depress agouti levels which will depress NPY. So the next time you see the sun don’t be afraid to get out there and enjoy catching those rays.
Leptin also has a dramatic effect on our taste buds and causes us to crave sweet things. When a person is leptin resistant the taste buds of that person do not properly receive the leptin signal. They crave carbohydrates and sweets, so we end up in a catch 22 until we address our leptin issues.
We have another hormone responsible for our food intake. This hormone is called ghrelin and is produced in the stomach. It tells you when it is time to eat.
This hormone has a very short life span. If the person does not satisfy this signal within the initial hour or so it will often just disappear along with your appetite.
Ghrelin production is stimulated by NPY and agouti. It is responsible for communicating with the pituitary gland to influence the metabolism.
Hard wired to eat
So from this you can see there are far more signals within the body that cause us to want to eat than what causes us to feel satisfied. You might wonder how I am meant to satisfy all these signals and help me feel satisfied after a meal.
Unfortunately there is no quick fix solution that I can give you. I can't say eats this and that and you will lose weight instantaneously or reach your perfect weight. This is because each and every person is different internally, in the same way we are all different externally.
So each diet though it may have similar guideline would have to be individual to each person.
Everybody will need different levels of fats, proteins and carbs so that they can feel satisfied after each meal they eat and fully express all their genetic strengths and attain true health. But from this we can see that all food types fats, proteins and carbs are so vital for your health. No person should try to eliminate any one of the food groups from their diet in an effort to loose unwanted pounds. It is simply unsustainable and unhealthy.