You could have completed your meal, but an hour or two later there is already a strong urge to eat again. It could be something sweet or a snack, and sometimes it is difficult to explain at all. This kind of hunger can be frustrating at times.
It is easy to blame a lack of willpower. But hunger is not simply a matter of deciding whether to eat. The brain is constantly receiving signals from the stomach, intestine, pancreas and fat tissue about how much energy is available. Several hormones are part of this conversation.
The hunger hormone
Ghrelin is often called the hunger hormone, and for good reason. It is produced mainly in the stomach, with levels tending to rise when the stomach is empty and before meals, and fall after eating. It is one of the signals that tells the brain that it is time to look for food.
This becomes particularly relevant during prolonged dieting or weight loss. The body does not always interpret weight loss simply as a positive change. Biological mechanisms that encourage food intake can become stronger, making hunger harder to ignore. Research has found that increased hunger and reduced satiety can accompany weight loss, with changes in several appetite-regulating hormones.
Then there is leptin, produced by fat tissue and helps the brain understand how much energy is stored in the body. In simple terms, it is part of the body's longer-term system for regulating energy balance rather than a hormone that switches hunger off after a single meal.
This is where the story becomes more complicated. People with obesity generally have plenty of leptin, but the body can become less responsive to its signal, a phenomenon known as leptin resistance. So simply having more of the hormone does not necessarily translate into feeling less hungry.
Your gut also has a say
The conversation does not end with ghrelin and leptin. After food reaches the digestive tract, hormones including peptide YY (PYY), cholecystokinin (CCK) and GLP-1 contribute to signals of fullness and help regulate how much and how often we eat. Protein and fat, for example, can stimulate some of these satiety signals.
This is one reason why a meal that contains mainly quickly digested carbohydrates may not feel as satisfying as a meal that also contains adequate protein, fibre and healthy fats. The physical volume of food is only one part of the satiety equation.
Not every craving is hormonal
This is an important distinction. A craving for chocolate at 4 pm does not automatically mean there is a 'hormone imbalance'. Food cues, stress, emotions, poor sleep, habits and the reward value of highly palatable foods can all influence eating behaviour. The brain's appetite system is closely connected to pathways involved in reward and pleasure, which is why a person can crave a particular food even when the stomach is not actually empty.
The role of sleep
Sleep deserves particular attention. When sleep is consistently poor, appetite and food choices can become harder to regulate. Stress can have a similar effect, although the response is not identical in everyone.
When constant hunger deserves a closer look
Occasional hunger is normal. Persistent, unusually strong hunger is different. If increased appetite is accompanied by excessive thirst, frequent urination, unexplained weight change, fatigue or other new symptoms, it is worth consulting a doctor. Diabetes, some medications and, less commonly, certain endocrine disorders can affect appetite or body weight. Hypothyroidism and Cushing's syndrome can contribute to weight gain, although they are not common explanations for obesity or persistent hunger.
The useful question, therefore, is not simply, “How can hunger be suppressed?” It is “What is driving the hunger?” Sometimes the answer is an overly restrictive diet or inadequate protein/fibre at meals. Sometimes sleep has been poor for months or the body is responding to weight loss with stronger biological signals to eat. And occasionally, there is an underlying medical issue that needs attention.
(The author is a consultant endocrinologist and diabetologist at KIMS-Arete Hospital)
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
