We are all accustomed to the feeling of hunger. It is partly due to a sensation of hunger elicited in the brain, a strong desire food and hunger pangs due to strong stomach contractions. We are also accustomed to the fact that these hunger signals subside after eating a meal. Some signals subside quicker than others but within a few minutes after a meal we no longer feel hungry. However, there are times when eating does not satify hunger and this can sometimes be a symptom of an underlying disease.
The body has several hunger signals that compels us to find food and eat. Most of these signals are due to a low blood glucose level which then triggers the hunger centers in the brain or by the stretching of the stomach when it is full with food. These hunger signals have several effects on the body. It elicits thoughts of food and increases the desire to eat which we refer to as appetite. It also triggers the stomach to start contracting strongly which we refer to as hunger pangs.
Failure to eat within a short period of time after these hunger signals arise leads to difficulty concentrating, fatigue and a host of other physical and cognitive impairments that are short-lived until we eat. We also begin to feel sleepy and if the blood glucose levels drop too low, there may even be a loss of consciousness. Naturally we expect all of these symptoms to resolve or be averted by eating a meal. However, this does not sometimes occur even with a large meal.
Read more on stomach noises.
Causes of Persistent Hunger
Ongoing hunger even after eating may not always be a sign of disease. Sometimes it is simply a dietery or lifestyle factor that is temporary. However, if there is persistent hunger after eating which continues for days or weeks then it may be necessary to consult with a medical professional for further tests.
Our body is conditioned to a certain level of physical and mental activity which usually correlates with our daily calorie needs. In other words we eat enough to sustain ourselves for our daily activities. These days people consume excess calories which leads to obesity. However, there are times when a person may overexert themselves, like with strenuous physical activity or prolonged mental tasks. It is therefore not uncommon for hunger to persist after eating if the calorie intake was insufficient.
As mentioned, the body is conditioned to a specific calorie intake during meals. Eating a smaller meal or meals with lower calories can lead to ongoing hunger after eating. It is not just about the portion size as the choice of foods that are eaten also plays a role. Some foods release glucose faster than others and the satiety response will therefore be more rapid. People who are fasting or dieting are more likely to feel hungry after eating as meals are missed sometimes or the calories are purposely lower to assist with weight loss.
The hunger centers are responsible for the sensation of hunger while the satiety centers in the brain shut down the hunger sensation. However, immediately after eating the satiety centers may not be fully activated. It takes a short period of time for the food to be digested and absorbed which then cases a rise in blood glucose levels. Depending on the portion size and choice of foods, there can be a delay between eating a meal and feeling satisfied. During this time a person may still feel hungry.
Persistent hunger is also a symptom of untreated diabetes. Since the body either lacks insulin or does not respond to insulin, the glucose remains in the bloodstream while it is needed by cells to produce energy. Furthermore the frequent urination that occurs in diabetes also constantly flushes out this needed glucose from the body. A persona may therefore find that they need to eat more but do not tend to gain weight. The latter is not always obvious in people who are obese.
Sometimes the discomfort or pain of a stomach condition is incorrectly interpreted as hunger pangs. This is seen with gastritis and peptic ulcer disease. In gastritis the stomach wall is inflamed whereas in peptic ulcer disease there are open sores in the stomach. This inflammation and sores may also occur in the duodenum, the first part of the small intestine which continues from the stomach. Eating food also sometimes relieves the pain for short periods. Therefore a person may want to eat as a means to remedy the pain that is thought to be hunger pangs.
NOTE: Any conditions that causes stomach pain may be mistaken for hunger pangs, including inflammatory bowel disease like Crohn’s disease which may involve the stomach. However, sometimes worsens the pain.
Read more on churning stomach sensation.
The body’s metabolism is largely regulated by the thyroid hormones which are secreted by the thyroid gland. If the thyroid hormone levels are high like when the thyroid gland is overactive then the metabolism will increase. This can lead to persistent hunger if a person does not increase their calorie intake to match the increased metabolism. Apart from the increased hunger, a person also experiences weight loss, elevated body temperature, difficulty sleeping and irritability or agitation as a result of hyperthyroidism.
Another reason for an increased appetite is intestinal worms. These parasites may reside and reproduce within the bowels where it consumes nutrients from food. It takes the some of the nutrients needed by the body. While there may not always be persistent hunger from eating, a person with a significant intestinal worm infestation may notice an increase in appetite usually without significant weight gain. Often there are no other symptoms unless the infestation is severe in which case abdominal cramps and diarrhea may occur.
Pregnancy is another common cause of increased hunger. As the fetal demands for nutrients increases, pregnant women may find an increase in appetite. By not eating more to accomodate for the fetal needs, a woman may find that she is hungry after a regular meal. It could be further exacerbated by gestational diabetes since the glucose in the bloodstream cannot enter the cells as efficiently and is flushed out as a result of frequent urination.