How do sugar and fat work in our brain?

In response to a WHO press release last October 2016, lhe global prevalence of obesity more than doubled between 1980 and 2014, being obese in that last year 11% of men and 15% of women (more than half a billion adults).

This figure is not worrying only because of what it means for our body to store large amounts of fluids and fats; furthermore, obesity is linked to addiction and certain mental disorders.

• Related article: "Compulsive overeating: food abuse and addiction"

A fat-oriented brain

Let's do a little experiment. As you read the following list of foods, imagine them as vividly and clearly as possible:

• Chocolate donuts.
• Cream buns.
• Ham and cheese pizza.
• Burger overflowing with sauce.
• Soft drink with ice.
• Chocolate milkshake with whipped cream.

Does your mouth water at the thought of those foods? That potent flavor, the sweetness of a glaze, the salty taste of fried smoked bacon… Don't panic, you're within the norm.

And it is that multiple studies show that human beings, by genetics, we have a preference for fats and sugars

. In fact, that preference turned out to be an evolutionary advantage for our ancestors by allowing the accumulation of fat in their bodies, ensuring survival in stages when food it was scarce.

Times change: overeating in fats and sugars

That these foods tasted especially pleasant was no coincidence.: indicated the presence of these elements. The organoleptic characteristics that precede them: the smell, texture, taste... were a great wake-up call for its consumption, just as it happens today.

However, there is unanimity that currently the current consumption of sugars and fats is excessive in relation to the current way of life. We are fully aware that an increase in the intake of these two foods is linked to the prevalent sedentary lifestyle it doesn't exactly do our health a favor. And surprisingly, it is difficult for many people to balance that intake despite the incidence that presents in the development of multiple diseases such as diabetes, hypertension, hypercholesterolemia or obesity.

So if in the long run it is so bad for us to eat fat and sugar... What makes us continue in this line? The answer is in our brain.

The Brain Reward Circuit

Also known as the Hedonic or Pleasure Circuit, is involved in motivation and the feeling of pleasure. It is composed of:

• The ventral tegmental area: It constitutes the central link of the reward circuit, since its neurons connect to numerous regions of the brain. It carries out the release of dopamine.
• The nucleus accumbrens: Increases brain dopamine levels
• The prefrontal cortex: directs the planning of cognitively complex behaviors, the expression of personality, decision-making processes and the adequacy of appropriate social behavior at all times (among others many)
• The pituitary: Releases beta endorphins and oxytocin, which relieve pain, regulate emotions such as love and positive bonds, among other functions.

What elements activate the brain's reward circuit? Among others, the love, tobacco, cocaine, marijuana, fats and sugars. But let's focus on these last two.

The psychological explanation of obesity

The process begins with the intake of foods high in sugar or fat, which stimulates the secretion of oxytocin and dopamine of our brain, which provides feelings of joy, well-being, pleasure and avoidance of discomfort, since dopamine participates naturally in functions such as food or sex.

Thus, after having eaten the donuts that we imagined above, our body feels good and the known hedonic pleasure, which constitutes a positive reinforcement on the behavior "eating donuts" (which, we will do again). But dopamine (neurotransmitter) and oxytocin (hormone) They have a limited life time, and upon their disappearance, the opposite feelings of well-being that we human beings crave so much remain, thus going from anxiety to sadness. The intake begins again and the cycle repeats.

• You may be interested: "Types of hormones and their functions in the human body"

The appearance of dependence on food

A phenomenon to take into account in the operation of this circuit is that dopamine and oxytocin each time disappear before the game and, in addition, the doses tend to decrease, for which, if the same level of excitement is desired as at the beginning, the amount or frequency of food intake must be increased, eventually becoming addicted.

This process can be related to the development of obesity, diabetes and the newly incorporated to the DSMV Binge eating disorder.

On the other hand, there are data that uncontrolled intake of sugars and fats have a higher prevalence in individuals suffering from obesity compared to normal weight individuals, but specifically in the obese group, occurs more frequently in depressed and / or anxious individuals.

Do fats and sugars act as an escape bomb from tense situations? Research indicates that, indeed, times of stress and situations that generate negative feelings lead these individuals to eat high fat and sugars to feel temporarily good, especially after reducing the level of dopamine, they again feel anxious and guilty for the lack of control shown or for having ignored their guidelines food.

And you, would you be able to reduce the consumption of processed sugar and saturated fat in your day to day?

To enlighten the reading public, I share a short documentary about what happens to the body when it lives a month without consuming sugar (you can subtitle it in Spanish).