Loss of appetite is the lack of desire to eat and in medical terms, it is called anorexia (x). This type of anorexia refers to unintentional appetite loss, which is not the same condition as anorexia nervosa, an eating disorder that causes patients to intentionally restrict their food intake as a concern about weight gain.
Usually loss of appetite is a result of an identifiable condition. It may result from a variety of conditions ranging from interaction with certain medications to more severe diseases. Most acute conditions trigger short-term appetite loss, but it can be a long-term symptom of some chronic diseases. Liver disease, heart failure, hormone disorders, metabolic problems, HIV and COPD may all cause patients to lose their appetites. Codeine antibiotics, morphine and chemotherapy medications may also trigger appetite loss. Pregnancy can also cause a loss of appetite (x).
Causes and Risk Factors for Loss of Appetite
The central nervous system, endocrine system and the digestive system communicate with each other in order to govern appetite regulation, which is a complex process. The hypothalamus is the head of the operation. A healthy, balanced appetite keeps the body in a homeostatic state, meaning the body gets sufficient energy and nutrients to maintain a healthy body weight (x, x). However, loss of appetite is a common problem and can occur for many reasons (x).
Infections and Illnesses
Bacterial, viral or fungal infections like gastroenteritis, flu and mononucleosis can cause appetite loss. Stomach and gastrointestinal tract infections as well as food poisoning can kill a patient’s appetite.
The American Society of Clinical Oncology (ASCO) revealed that appetite loss is common in patients with cancer or patients undergoing cancer treatment. The disease and its treatments, such as chemotherapy, can cause changes in digestion, hormone production and metabolism, which can cause appetite loss (x, x). Specifically, stomach, rectal, colon and bladder cancer are common causes of appetite loss because they cause inflammation in the digestive organs (x, x, x).
Hypothyroidism is a condition in which the thyroid gland is underactive and doesn’t produce enough hormones. The condition can cause mood swings, fatigue and appetite loss (x).
Kidney or Liver Failure
An imbalance of intestinal hormones such as ghrelin, peptide-YY and cholecystokinin can cause loss of appetite. Ghrelin is secreted by the stomach and helps increase appetite, especially during fasting periods. Peptide-YY is secreted by the ileum and colon to suppress the appetite and cholecystokinin is secreted by the small intestine to help suppress the appetite (x).
Aging causes a decrease in metabolism and changes to the digestive system, which can lead to appetite loss. Other age-related factors can include medications, ill-fitting dentures, changes in taste and smell, low activity levels and pain. About 20 percent of aging adults experience unintentional weight loss due to some of these factors (x). Severe appetite loss can lead to more severe, potentially fatal consequences (x, x, x).
Exercising may have an effect on appetite. There are many different factors that contribute, including intensity, duration, type of exercise, diet and mentality. For example, research states that more difficult workouts tend to suppress appetite, but lower or moderate intensity workouts increase it. Also, longer workouts take longer to cause hunger than shorter workouts (x).
Other Illnesses such as inflammatory bowel disease (IBS) and depression can lead to appetite loss that may last for weeks or months. Continuous weight loss can be detrimental due to a lack of nutrients that provide energy.
Symptoms Accompanying Loss of Appetite
Loss of appetite causes a lack of desire to eat, even if the patient has not eaten for a long period of time, which can lead to unintentional weight loss. If it occurs temporarily as a result of an illness or emotional stress, the appetite usually returns after the sickness passes and there is no risk of significant weight loss. However, decreased appetite can cause other health problems. Some other signs to look out for that often accompany loss of appetite include (x, x, x):
- Trouble focusing
- Water retention and swelling
- Weakness and fatigue
- Constipation (x)
- Nausea, heartburn and bloating
- Low motivation and mood changes (x)
- Body aches and fever
- Reproductive difficulties
- Menstrual changes
Treatment for Loss of Appetite
Depending on the severity of the symptom, certain medications may increase appetite. Dronabinol and megestrol help regulate appetite (x, x). Studies show that antidepressants and steroids may also stimulate appetite (x, x, x). However, these medications may cause side effects, so consult a doctor before taking any medication.
Eat Green Vegetables
Drink Plenty of Water
A loss of appetite can cause dehydration, so drink plenty of water to stay hydrated. If a slow digestive system is the cause of a decreased appetite, increase water intake to help boost the digestive system (x).
Exercise is vital for a healthy, functioning body and is an excellent appetite booster. You may lose your appetite during exercise, but it generally comes back after resting. For example, swimming is one of the best forms of exercise to boost the appetite (x).
Supplements for Digestion
Containing healthy fatty acids, fish oil is an excellent natural supplement that affects mood, heals acne and improves heart health. In a research study, subjects who took fish oil supplements before breakfast experienced an increase in appetite (x). Take one or two fish oil softgels two or three times every day or follow a physician’s instructions on dosage.
Vitamin B1 (Thiamine)
Also called thiamine, vitamin B1 performs several different functions in the body, including boosting metabolism and reducing digestive problems. Folic acid and vitamin B1 can be found in poultry, green leaves and vegetables, so eating a healthy diet with thiamine supplements may help improve digestion and increase the appetite. Take vitamin B1 powder in 50 to 100 mg doses every day, unless a physician recommends otherwise.
Low zinc levels are associated with gastrointestinal disease and helps regulate hormones and metabolism. It also has an effect on appetite (x). Foods that are high in zinc include cashew nuts, oysters, chicken and pumpkin seeds. The recommended dosage for zinc gluconate powder is between 225 and 450 mg per day, unless a physician advises otherwise.
The Bottom Line
Loss of appetite is the lack of desire to eat and is medically referred to as anorexia (x). This type of anorexia refers to an unintentional loss of appetite, which is not the same condition as anorexia nervosa, an eating disorder with intentional food restriction.
Appetite loss is a common symptom of a variety of acute conditions, such as the flu or mononucleosis. It may also develop as a result of more chronic conditions, such as cancer, kidney disease or liver failure. It also often accompanies other symptoms including insomnia, fatigue, constipation, bloating and nausea.
Medications can help boost appetite, such as dronabinol, megestrol, antidepressants and steroids. Patients can also use home remedies to increase their appetites—drinking plenty of water, exercising and eating green vegetables. Supplements may also help aid digestive health, like zinc, vitamin B1 and fish oil. Although they may help, supplements are not intended for medical treatment. Always consult a doctor before taking any supplement and follow their instructions.