What are hunger signals and how do they work?
Hunger signals are part of the body's system for regulating energy intake and body weight. Appetite and fullness are controlled through an interaction between the brain, gastrointestinal tract, adipose tissue and several different hormones that help the body adjust energy intake according to its needs.
The hormone ghrelin, which is mainly produced in the stomach, is often referred to as the body's hunger hormone. Levels often rise before meals and signal to the brain that it is time to eat. When we eat, several hormones are instead released from the gut, including GLP-1 and PYY, which contribute to increased fullness and reduced hunger.
The body's adipose tissue also affects appetite regulation through the hormone leptin. Leptin signals to the brain how much energy is stored in the body and normally helps reduce appetite when energy reserves are sufficient.
Appetite regulation is also influenced by the brain's reward system. Food can produce feelings of pleasure and reward, which means that we sometimes eat for reasons other than physiological hunger. Energy intake is therefore controlled by both the body's biological needs and the brain's experience of reward.
The regulation of hunger and fullness is complex and is influenced not only by hormones but also by factors such as sleep, stress, physical activity, eating habits and body weight. Appetite regulation can therefore work differently in different people and change over time.
Why do hunger and hunger signals increase during weight loss?
When you lose weight, the body activates several biological mechanisms aimed at preserving energy reserves. This is a natural adaptation that has developed to protect the body against prolonged energy deficiency.
During weight loss, the levels of several hormones that affect hunger and fullness change. Hunger signals can increase while fullness signals decrease, which means that many people experience increased appetite and a greater focus on food. The body can also adapt its energy expenditure, meaning that it uses slightly less energy than before.
These changes can contribute to weight loss often becoming more difficult over time and can make maintaining a lower weight in the long term challenging. The strength of these adaptations varies between individuals, but they illustrate that body weight is not controlled solely by willpower, but also by biological processes that affect hunger, fullness and energy balance.
How do sleep and stress affect hunger signals?
Sleep and stress can affect the body's regulation of hunger and fullness. Research shows that too little sleep can alter the levels of several hormones involved in appetite regulation, which can contribute to increased hunger and reduced feelings of fullness.
Many people also experience increased cravings for energy-dense foods when they get too little sleep. At the same time, tiredness can affect concentration, impulse control and the ability to make considered decisions about food and lifestyle habits. Lack of sleep has therefore been linked to higher energy intake in many people.
Stress can also affect appetite, but the effect varies between individuals. Some people experience reduced hunger when stressed, while others experience increased appetite and greater cravings for energy-dense foods. Long-term stress can also make it more difficult to maintain healthy habits around diet, physical activity and sleep.
Because both sleep and stress affect the body's biological systems for hunger and fullness, good recovery and stress management can be important parts of sustainable long-term weight regulation.
How can diet affect hunger signals?
Food choices can affect both hunger and fullness. Foods that provide greater fullness can make it easier to manage appetite and maintain healthy eating habits over time.
The following strategies can be helpful:
Prioritise protein-rich foods
Protein contributes to increased fullness and can help reduce hunger between meals. Try to include protein-rich foods such as fish, eggs, chicken, dairy products or pulses in your meals throughout the day.
Eat more fibre-rich foods
Vegetables, fruit, pulses and wholegrains contain fibre that contributes to increased fullness and can help create more stable energy levels throughout the day.
Eat slowly and mindfully
It takes time for the body to register fullness. Eating at a relaxed pace and allowing enough time for your meal can make it easier to notice the body's fullness signals.
Drink enough fluids
Getting enough fluids is important for health and, for some people, can make it easier to interpret the body's signals for hunger and fullness.
Regular meals
For many people, regular meals can reduce the risk of strong hunger later in the day and make it easier to make considered food choices.
No single strategy works for everyone, but a combination of protein-rich and fibre-rich foods, regular meals and healthy lifestyle habits can contribute to better appetite regulation over time.
How can GLP-1 medicines affect hunger and fullness?
GLP-1 receptor agonists are a group of medicines used in the treatment of obesity and type 2 diabetes. The medicines mimic the effects of the body's own gut hormones and can contribute to increased feelings of fullness, reduced appetite and lower energy intake.
GLP-1 affects several of the biological systems that regulate hunger and fullness. The medicines slow stomach emptying and send signals to the brain that contribute to increased fullness after meals. Many people also experience reduced food cravings and less focus on food during the day.
For people living with obesity, these effects can make it easier to follow healthy lifestyle habits and maintain weight loss over time. Medication should, however, be seen as a complement to dietary changes, physical activity and other lifestyle measures.
Obesity is a chronic disease influenced by biological, psychological and environmental factors. For some people, medication can be an important form of support for improving weight regulation and metabolic health.
Frequently asked questions about hunger signals (FAQ)
Which hormone controls the body's hunger signals?
There is no single hormone that controls hunger and fullness. Instead, appetite is regulated by several hormones that interact with the brain and other parts of the body.
Ghrelin is often referred to as the hunger hormone because levels rise when the stomach is empty and signal that it is time to eat. Hormones such as GLP-1, PYY and leptin instead contribute to fullness and help the body regulate energy intake over time.
Appetite is also influenced by factors such as sleep, stress, physical activity, eating habits and the brain's reward system. Hunger and fullness are therefore the result of a complex interaction between several biological processes.
Why do I feel strong hunger signals shortly after a meal?
There are several possible reasons why hunger returns shortly after you have eaten. The composition of the meal plays an important role. Meals containing little protein or fibre may provide less fullness than meals with a higher proportion of protein-rich and fibre-rich foods.
Lack of sleep, stress, physical activity and individual differences in appetite regulation can also affect how full you feel after a meal. Some people may also have higher energy needs, which means that hunger returns more quickly.
If you often become hungry shortly after eating, it can be helpful to review the content of your meals and make sure they contain enough protein, fibre and other nutritious foods that contribute to increased fullness.
How can I distinguish between biological hunger signals and emotional cravings?
Biological hunger usually develops gradually and is the body's way of signalling that it needs energy. It can usually be satisfied by different types of food and is often accompanied by physical signs such as a feeling of emptiness in the stomach, low energy or difficulty concentrating.
Emotional cravings, on the other hand, often arise more suddenly and are usually linked to emotions, habits or specific situations. They can be triggered by stress, boredom, anxiety or social situations, for example, and are often directed towards specific foods, such as sweets or snacks.
It is not always easy to distinguish between hunger and cravings, because both biological signals and the brain's reward system influence our eating behaviour. Pausing to consider when you last ate, how you feel and what you are craving can sometimes help you better understand your body's signals.
Do hunger signals decrease permanently if you lose weight?
Weight loss can improve many aspects of health, but hunger signals do not always decrease permanently. On the contrary, research shows that the body often adapts to a lower weight by increasing hunger and reducing fullness signals. These biological changes can persist for a long time after weight loss.
The strength of these adaptations varies between individuals. Some people find that their appetite stabilises over time, while others continue to experience increased hunger compared with before weight loss.
This is one reason why maintaining weight loss is often more difficult than losing weight initially. Healthy eating habits, regular physical activity, good sleep and, in some cases, medication can help manage hunger signals and support long-term weight regulation.
What is important to consider when eating to reduce my hunger signals during weight loss?
During weight loss, it is common for hunger signals to increase. It can therefore be valuable to choose foods that provide good fullness and help you maintain a sustainable energy balance over time.
Protein-rich foods such as fish, eggs, chicken and pulses often contribute to increased fullness. Fibre-rich foods such as vegetables, fruit, wholegrains and pulses can also help you feel full for longer between meals.
For many people, eating regular meals and avoiding becoming overly hungry can also work well, as strong hunger can make it more difficult to make considered decisions about food. Eating at a relaxed pace and giving the body time to register fullness signals can also be helpful.
The most important thing is to find eating habits that work in the long term and provide enough nutrition while supporting your health and weight goals.
.svg)