Food and Brain’s Chemistry

by Tala Mustafa - Clinical Dietitian at Aman Lil Afia Clinic ????? ???? ???????

Food digestion and internal processing has a direct effect on physical, hormonal, neurological functioning, metabolic processes, appetite control and weight changes. It is important to understand how what we eat influences our appetite and eating habits.

Many people view hunger as the mistrusted enemy to be controlled at all costs. People can also view hunger similarly as cravings, yet they can reflect different needs. By understanding hunger, we can meet our body needs with ease and comfort.

How do I know I am hungry?

Hunger is a physical signal from your body for nutrients. When you’re physically hungry, you might experience a range of symptoms like:

-Feeling a hollow tummy

-Thinking about and searching for food,

-Looking at the clock to see if it is mealtime,

-Not being able to concentrate.

-Feeling lightheaded and irritable.

Hunger reflects energy needs, it’s a natural response regulated by internal mechanisms and brain chemicals, therefore mastering hunger does not depend on willpower, and it can be a losing game.?

What generates appetite?

Our bodies have a complex system that monitors nutrient stores like glucose, fats, and proteins. When these nutrient levels drop, the brain signals hunger, motivating us to eat and restore balance and satisfaction which eventually reduces appetite and generates satiation. Hunger can also be triggered by the sights and smells of food, and influenced by factors like genes, eating behaviors, illnesses and stress, physical activity, hormones, and menstrual cycle.

The Wanting Vs. The Liking Brain

Hunger originates in the brain through a dual system. On one hand, the wanting brain prioritizes restoring energy and nutrient balance, responding fast to low blood sugar and it is regulated by neurotransmitters and hormones.

The liking brain, on the other hand, responds to fat-sugar combination in satisfactory foods, therefore it is regulated by reward pathways of endorphins and dopamine, and it increases the desire for such foods. This liking brain can overpower the wanting brain’s signals.

How can dieting affect appetite?

The net effect of dieting can be a disturbed relationship with food, and improper hunger and cravings management that might be interpreted as emotional eating.

Restrictive diets can cause a physical and emotional dysregulation, where eating isn’t guided by hunger, but by rules and beliefs.

Conversely, chaotic eating, overeating, and undereating can lead to hormones, neurotransmitters and blood sugar disturbances which affects brain mechanisms, the overall physical and mood status leading to cravings, stress, fatigue, and easy weight gain.

The key influencers on appetite and hunger:

1. Low blood sugar: Prolonged periods without food, inadequate energy and carbohydrates intake can lead to low blood sugar, causing tiredness, irritation, difficulty concentration, unstable weight, and stimulating hunger and cravings.
2. Serotonin: a mood regulating neurotransmitter that also suppresses the desire for carbohydrates and snacking. Low serotonin levels resulting from inadequate carbohydrates intake can lead to depression, impulsiveness, short attention span, and cravings.
3. Neuropeptide Y (NPY): This neurotransmitter stimulates appetite particularly for carbohydrates when blood sugar drops leading to an increase in NPY levels in the brain. NPY naturally peaks one hour before the dark, and triggers food intake in the late afternoons which might explain why diets are often broken in the late afternoon.
4. Low Endorphins: can increase cravings for fatty-sugary foods while triggering overwhelm feelings and low mood. The intake of fatty/sugary foods such as ice cream or chocolate stimulates endorphins and causes a transient fall in appetite, but constantly eating them will eventually desensitize this system, requiring larger quantities to obtain the same pleasing effect. Endorphins can reduce hunger but only when diet is adequate.
5. Dopamine is released when satisfaction is experienced with eating, which in turn regulates the liking brain and reduces the desire to eat.
6. Low Tryptophan amino acid: can result from inadequate protein intake leading to low serotonin which might increase carbohydrate cravings. It is important to ask yourself whether your cravings are arising because of imbalanced meals? Note: Food Tryptophan sources are eggs, dairy products, poultry, meats, and legumes.
7. Exercise: Rapid Endorphins fall after exercise can create hunger. While regular exercise can increase baseline hunger, it can also protect against emotional eating.
8. Menstrual Cycle: Hunger reduces during the first part of the cycle where estrogen increases, and then an increase in appetite continues towards menstruation. After ovulation, endorphin falls and results in cravings for a short period of time. It is also important to note that energy levels increase slightly during menstruation which can also increase hunger feelings.

Harmony is Key!

Our bodies are complex systems, and extreme or unbalanced eating behaviors can disrupt the delicate balance between brain chemicals and body needs. By understanding how food affects us, we can make informed choices to nourish our bodies and minds and emphasizing the importance of a balanced diet.