Changes in appetite are not just a reaction to stress or changes in weather. If you notice that you are eating significantly more or, conversely, have lost interest in food, this may be a signal that the balance in your body has been disrupted. We explain which systems to check and what symptoms to pay attention to.
Appetite as an Indicator of Health
The feeling of hunger is regulated by several systems — the nervous, endocrine, and digestive systems. When they work in harmony, the body clearly understands when it needs to replenish energy reserves. However, if one of the systems fails, appetite can change dramatically: some people stop feeling hungry, while others experience a constant desire to snack. This is often related to hormonal fluctuations, sleep disturbances, or metabolic issues.
Endocrine System and Appetite Hormones
Appetite regulation begins with hormones that transmit signals between the body and the brain. Leptin, produced by fat cells, signals satiety, while ghrelin signals hunger. When this mechanism is disrupted, for example, due to insulin resistance, stress, or thyroid problems, a person loses control over their sense of fullness.
Leptin deficiency causes a constant feeling of hunger, while in hyperthyroidism (increased thyroid function), appetite increases despite weight loss. In contrast, hypothyroidism decreases appetite, accompanied by drowsiness, a feeling of cold, and apathy.
Gastrointestinal Tract and the Gut-Brain Axis
The gastrointestinal tract actively participates in appetite regulation. It produces dozens of hormones that influence hunger centers in the brain.
If digestion is impaired — for example, due to gastritis, delayed gastric emptying, or microbiota imbalance — appetite often decreases. Food is digested more slowly, heaviness occurs, and the desire to eat disappears.
Excessive consumption of simple carbohydrates, on the other hand, can lead to constant hunger. This creates a vicious cycle: the more fast carbohydrates consumed, the sharper the spikes in blood sugar, and the stronger the craving for food.
Additionally, the gut is closely connected to the brain: when the microbiota is disrupted, serotonin production decreases — a neurotransmitter responsible for mood. This can manifest as apathy, anxiety, and difficulty concentrating.
Nervous System and Stress
The hypothalamus is a part of the brain that regulates responses to physical and emotional signals. During stress, cortisol levels rise: for some people, this suppresses appetite, while for others, it increases it.
Chronic stress often leads to overeating and cravings for "comfort" foods high in sugar and fat. In contrast, during short-term stress due to adrenaline release, appetite temporarily disappears.
If you notice that changes in eating behavior are accompanied by irritability, insomnia, and fatigue, the cause may be related to stress levels rather than gastrointestinal issues.
Metabolism and Energy Balance
With age, metabolism naturally slows down, which also affects appetite. People who lead a sedentary lifestyle often do not feel hungry in the morning, but in the evening, they struggle to control their food intake — this is related to disrupted circadian rhythms and fluctuations in glucose levels.
Vitamin D deficiency, anemia, and lack of magnesium or iron can also affect hunger perception. In cases of energy imbalance, the brain perceives the situation as stress and may either increase appetite or, conversely, "turn it off" to conserve resources.
When to See a Doctor
Appetite is an important biological indicator, and changes should not be ignored. If the disruption lasts longer than a few weeks or is accompanied by other symptoms, it is necessary to undergo an examination.
It is recommended to visit an endocrinologist (to check levels of thyroid hormones, leptin, ghrelin, insulin), a gastroenterologist (to assess the condition of the stomach and intestines), and a therapist (to check levels of iron, vitamin D, and glucose).
Reasons to consult a specialist:
- appetite changes persist for more than 2–3 weeks;
- there is a sudden decrease or increase in weight;
- fatigue, apathy, or sleep disturbances have appeared;
- there are increased heart palpitations or anxiety states.
Source: Kleo.ru
