Loss of Appetite: Causes, Weight Loss and When to Worry

What loss of appetite feels like

You may not feel hungry at mealtimes, feel full after a few bites (early satiety), feel nauseated by food or its smell, or find food tasteless. It is different from deliberately eating less. Loss of appetite is common in older adults, partly because taste, smell and activity decline with age, but a marked change is still worth checking.

Common causes

Short-term causes

• Infections: colds, flu, COVID-19, stomach bugs and urinary tract infections. Appetite usually returns as you recover
• Nausea and digestive upset: food poisoning, indigestion, constipation
• Stress, grief and anxiety
• Pain anywhere in the body
• Medicines: antibiotics, opioids, chemotherapy, metformin, GLP-1 drugs such as semaglutide, ADHD stimulants, some antidepressants, digoxin
• Pregnancy, especially the first trimester
• Alcohol or drug use, including withdrawal

Longer-term causes

Loss of appetite and weight loss together

When poor appetite comes with unintended weight loss, the body is not getting enough energy, and a cause should be found. Doctors consider weight loss significant when it reaches about 5% of your body weight over 6 to 12 months. Patterns that guide them:

• With tiredness and lethargy: depression, thyroid disease, diabetes, anemia, kidney or liver disease, chronic infection, cancer.
• With nausea or stomach pain: gastritis, ulcers, gallstones, pancreatitis, stomach or pancreatic cancer.
• With night sweats or fever: tuberculosis, HIV, lymphoma, other infections.
• With swallowing difficulty: esophageal narrowing or cancer.
• In a young man: depression, substance use, diabetes (type 1), inflammatory bowel disease, hyperthyroidism, and less commonly testicular cancer or lymphoma.
• In older adults: depression, dental problems, medicines, social isolation and cancer are the main causes.

Weight loss without loss of appetite, where you are eating normally or more, points more to diabetes, an overactive thyroid or malabsorption. See recent weight loss for more on unexplained weight loss.

How doctors find the cause

A doctor will ask how long it has lasted, how much weight you have lost, about mood, medicines, alcohol, diet, bowel habits, swallowing, pain and night sweats. They will examine you, including weight, mouth and teeth, lymph nodes, thyroid, abdomen and chest. Common tests include:

• blood count, kidney and liver function, blood sugar and HbA1c, thyroid function, calcium, inflammation markers (CRP), and often HIV and hepatitis tests
• urine tests
• stool test for hidden blood (FIT)
• chest X-ray
• further tests as needed, such as endoscopy, CT scan or a depression screening questionnaire

Treatment and what helps

Treating the cause usually restores appetite. While that happens:

• Eat small amounts often: 5 or 6 small meals or snacks rather than 3 big ones.
• Make every bite count: add calorie- and protein-rich foods such as nut butters, eggs, cheese, yogurt, olive oil and milk.
• Drink between meals, not with them, so you do not fill up on fluid.
• Use nutrition drinks if eating is hard.
• Make food appealing: favorite foods, eating with others, a short walk before meals.
• Manage nausea: cold foods smell less, and ginger may help. Ask your doctor about anti-nausea medicine.
• Review medicines with your pharmacist or doctor.
• Get dental problems fixed, and adjust ill-fitting dentures.

In some situations, such as cancer, doctors may prescribe appetite stimulants. These need careful discussion because of side effects.

Frequently asked questions

What causes loss of appetite and weight loss?

Common causes include depression, anxiety, ongoing infections, digestive problems such as gastritis or inflammatory bowel disease, thyroid or kidney disease, medicines and, less often, cancer. If you have lost 5% or more of your weight over 6 to 12 months without trying, see a doctor for tests.

When should I worry about loss of appetite?

See a doctor if poor appetite lasts more than 2 weeks, or sooner with weight loss, vomiting, difficulty swallowing, blood in stool, yellow skin, night sweats, persistent tiredness or a lump. Seek urgent help if you cannot keep fluids down or have thoughts of self-harm.

Can anxiety cause loss of appetite?

Yes. Anxiety and stress release hormones such as adrenaline that suppress hunger and slow digestion, causing nausea and a knotted stomach. Appetite usually returns when the stress eases. Persistent anxiety affecting your eating is worth discussing with a doctor or therapist.

What causes loss of appetite, weight loss and tiredness together?

This combination can point to depression, an underactive or overactive thyroid, diabetes, anemia, chronic kidney or liver disease, tuberculosis, HIV or cancer. A doctor will usually start with blood tests and an examination to narrow down the cause.

How can I increase my appetite?

Eat small, frequent meals, choose energy-dense foods, drink between rather than with meals, stay active, and make meals social and enjoyable. If a medicine is reducing your appetite, ask whether there is an alternative. Persistent poor appetite should be checked by a doctor.