Craving food is human nature.
When our stomach is empty, it releases a “hunger hormone” called ghrelin, which sends signals to our brain to inform the need for food.
As a result, we will now have the appetite to eat.
However, this mechanism is not always true.
You may not want to eat even though your body is starving, or your appetite is still good despite a full stomach.
Of course, both are not good for your health.
In this article, we will focus on the first scenario: loss of appetite.
What is loss of appetite?
Loss of appetite simply means you no longer have the desire to eat. “Poor appetite” and “anorexia” (medical term) are two terms describing the same symptom.
Do not confuse “anorexia” with “anorexia nervosa” – the latter is an eating disorder that requires a proper diagnosis by a medical doctor. Nevertheless, anorexia nervosa can lead to a loss of appetite.
We will discuss all the causes of appetite loss in this article later.
When we lose appetite, we might experience the following symptoms:
- No desire to eat food
- Feel full or cannot feel hungry
- Not enjoy or be annoyed by the taste, sight, or smell of food
What causes loss of appetite?
Loss of appetite can occur suddenly (acute) or develop gradually over a long period of time (chronic). Acute appetite loss is usually temporary and less worrying.
On the other hand, chronic appetite loss can hint at something more sinister and persists for a more extended period. Here, we will see a few common causes of appetite loss.
Loss of appetite due to infections is brief and temporary. All types of infections, such as bacterial, viral, fungal, or parasite, at any body part can cause loss of appetite.
A few prevalent infections are:
- Upper respiratory tract infection
- Urinary tract infection
- Acute gastroenteritis
- Acute colitis
- Acute pancreatitis
- Skin infections
When a pathogen invades our bodies, our immune response is activated. Inflammation happens, and various inflammatory substances, including cytokines and interleukins, are released. They, in turn, increase the production of leptin.
Opposite to ghrelin, leptin is a hunger-suppressing hormone. It tells our brain that we are full, even though the stomach is empty. As a result, we tend to lose appetite during infectious illnesses.
Symptom of appetite loss is most prominent in infection of digestive organs, including the stomach, small bowel, large bowel, and pancreas. Nausea and vomiting deteriorate appetite loss in patients with digestive system infections.
Emotions can significantly impact our appetite. Sadness, depression, anxiety, and stress have all been linked to unusual eating symptoms, mostly a reduced desire to eat.
Compared to brief emotional changes, many mental illnesses can impact appetite to a greater extent. These include:
- Anorexia nervosa. It is an eating disorder characterized by self-starvation, intense fear of weight gain, and body image disturbance. People with anorexia nervosa restrict their calorie intake to an extremely low level below their body requirement. Anorexia nervosa is a well-known lethal mental illness. According to the National Eating Disorders Association, people with anorexia nervosa have a six-fold higher mortality rate than the general population. Root causes of death include malnutrition, substance abuse, and suicide.
- Anxiety disorders. There are four types of anxiety disorders: generalized anxiety disorder, panic disorder, social anxiety disorder, and various phobia-related disorders. The National Institute of Mental Health estimates that 31.1% of adults in the United States will experience at least one type of anxiety disorder throughout their lifetime. Having appetite loss is common for people with anxiety disorders.
- Post-traumatic stress disorder (PTSD). PTSD happens when someone goes through traumas that are usually life-threatening. Examples of events include violence, disasters, and accidents. Life of people with PTSD is severely disturbed. Survivors can be compelled to replay the traumatic memories, detached from reality, and easily startled. Sleeping and eating become challenging tasks for them.
- Major depressive disorder (MDD). People with MDD can present either appetite loss (48%) or an increased appetite (35%), as reported by a study in 2016. In people with MDD, the part of the brain in charge of hunger response towards appetizing-looking food cannot function well. Also, they often lack energy and are unable to feel pleasure when eating. All these explain why people with MDD experience appetite loss.
Chronic medical conditions
Studies show nearly all patients with chronic medical illnesses suffer from loss of appetite. Examples of these long-term diseases include:
- Digestive problems, such as irritable bowel syndrome, inflammatory bowel disease, and gastroparesis
- Chronic liver disease
- Chronic kidney disease
- Heart diseases
- Chronic lung diseases
- Chronic hepatitis
- HIV infection and AIDS
- Chronic pain and migraines
- Underactive thyroid (Hypothyroidism)
Loss of appetite is an alarming feature of cancer. Almost all cancer patients develop poor appetite and unintentional weight loss symptoms.
The mechanism behind it is complex, but scientists believe it is due to chronic inflammation that releases various inflammatory molecules.
Besides the loss of appetite, people with severe chronic illnesses and cancer often suffer from cachexia, a wasting syndrome characterized by loss of muscle weight and fat. Loss of appetite and cachexia together cause significant body weight drop and severe malnutrition.
Researchers estimate that 70–80% of pregnant women experience morning sickness. This translates to 4 million women being affected yearly in the United States.
Due to drastic hormonal changes in pregnancy, women often experience nausea and vomiting in the first trimester. In severe cases, a diagnosis of hyperemesis gravidarum can be made.
Smells or sight of food can trigger nausea, and eating becomes a challenge to them. Other body changes, such as breast tenderness and stress in pregnancy, can all lead to loss of appetite in pregnant women.
Appetite loss in the elderly is known as anorexia of aging, a physiological reduction in appetite and food intake following the process of aging. It is a common phenomenon in the elderly.
Studies reported around 15 to 30% of the elderly experience loss of appetite. Researchers have discovered some of the reasons why elderlies have appetite loss, including but not limited to the following:
- Reduced sense of smell and taste
- Diminished sensory function in feeling full (sense of satiety)
- Increased activity of inflammatory mediators (cytokine)
- Altered gastrointestinal function
- Delayed emptying of the stomach, hence quickly feeling full once start eating
- Hormonal effect
Appetite loss causes a 30% decrease in daily energy intake, leading to undesirable body weight loss and a deteriorated health condition among the elderly.
Some medications and drugs can make you lose your appetite. For example:
- Antimicrobials, including certain antibiotics, antifungals, and anti-virals
- Blood pressure medications
- Heart failure medications
- Chemotherapy treatments
- Psychiatric medications, including antidepressants, antipsychotics, and mood stabilizers
- Illicit drugs, such as cocaine, heroin, and amphetamines
Accompanying symptoms and complications
If the root cause of your reduced appetite is a short-term problem, you will likely resume your appetite once the acute disease has been treated.
However, if your appetite loss is induced by a chronic condition, your appetite loss may worsen and cause more symptoms, such as:
- Lethargy or extreme fatigue
- General weakness and malaise
- Unintentional body weight loss
- Rapid heart rate
Persistent appetite loss imposes a high risk of malnutrition and electrolyte deficiencies. These complications are potentially life-threatening.
Therefore, you should pay attention to your health condition, check for any associated symptoms, and seek medical attention if your appetite does not improve after the acute incident.
Should you see a doctor?
Loss of appetite is not a medical emergency. However, you should see a doctor if your appetite loss persists for more than 1 to 2 weeks or when you have any of the following symptoms:
- Very dry mouth, lips, and eyes
- Dizziness or light-headedness
- Extreme lethargy
- A minimal amount of urine output or reduced frequency of urination
- Chest pain
- Fast heartbeats and palpitations
- Numbness or weakness of part of the body
- Confusion or altered mental status
- Self-harm or suicidal thoughts
What to do if you have no appetite?
Everyone loses appetite at some point in their life. Although ideally, you should not skip any meal, it is OK if you don’t feel like eating or are uncomfortable with eating.
Here are some things you can do if you have no appetite but still can tolerate food:
- Eat a smaller portion at short intervals between meals.
- Do not rush. Eat slowly, chew the food thoroughly, and only take another spoon after swallowing the food in your mouth.
- Make your food look as attractive as possible. Use your favorite plates and utensils, arrange the food neatly and garnish the food with colors, such as lemon, tomato, or parsley.
- Substitute red meats with lighter protein sources, such as fish, chicken, eggs, or low-fat cheese.
- Eat your food in a conducive environment.
- Stay away from places with smells, such as the kitchen.
- Take anti-nausea medications at the first sign of feeling nauseous.
- Appetites fluctuate with our mood. Ensure you eat well during your good days, and try to practice the tips above during your bad days. Eating a little bit is better than none.
What to eat when you have no appetite?
When you are having an appetite-down day, it may be hard to swallow the food you usually take.
Here are some tips on how you can still get sufficient nutrients with a smaller portion of your food intake:
- Eat high-calorie, high-protein food loaded with healthy fats.
- Add calories to meals using butter, oil, or condiments such as peanut butter.
- Drink meal replacement beverages, such as Boost®, Ensure®, Orgain®, and Glucerna
- Keep snacks with you and eat them whenever you desire to eat. Nuts, crisps, dried fruit, or a bowl of grated cheese are light and tasty.
- Take liquid food that is easy to swallow, such as yogurt and creamy cheese.
Treatment for appetite loss
Loss of appetite usually resolves once the root causes have been taken care of. However, there is no cure for most chronic diseases.
In such cases, you will need a regular follow-up with your doctor to optimize your disease control, which will, in turn, improve your appetite.
Appetite stimulants are the class of medication used to treat loss of appetite. They come with oral tablets or suspensions.
Currently, under this class of medicine, there are only three drugs approved by the U.S. Food and Drug Administration (FDA): megestrol acetate, oxandrolone, and dronabinol.
However, the drugs are not for everyone and they can only be used in two conditions:
- AIDS-related anorexia and cachexia
- Palliative treatment in advanced breast and endometrial cancers
Your doctor will also treat the associated symptoms and complications caused by loss of appetite. For example:
- If you develop malnutrition due to appetite loss and reduced food intake, you may be given nutrients that are directly transfused into your blood (parenteral nutrition)
- If your loss of appetite is caused by mental health conditions or drug abuse, you may be referred to a mental health specialist.
- If medications are the culprit of your appetite loss, your doctor may adjust the dosage or directly change the prescription. Do not change the medications by yourself.
Tips to improve your appetite
At this stage, you should have learned many tips on how to fulfill your nutritional requirement despite having a poor appetite. Last but not least, here are some tips on how to improve your appetite in general:
- Exercise regularly. Light exercise before meals, like a short walk, can stimulate your appetite.
- Stay hydrated. Drink 6 to 12 cups of water daily to avoid dehydration.
- Get optimal rest.
- Practice having a regular meal time.
- Plan your meal a day before.
Frequently asked questions
Why do I have no appetite and feel sick when I eat?
There are many possible reasons behind this. Most of the time, it is due to an acute medical illness, such as acute gastroenteritis or food poisoning, and when you are under stressful situations.
I am hungry, but I have no appetite- what should I do?
You should eat! Feeling hungry even though you have no appetite is a good sign. Your body is telling you that it is starving and you need food.
Follow the tips as discussed, and eat your usual portion of food. Remember not to overeat.
Loss of appetite is a common yet potentially debilitating problem. You should not take it lightly.
Monitor your health condition, and do not hesitate to consult a medical professional if you have any questions.