What is unexpected weight loss?

This means losing weight without trying to. Weight loss most often happens slowly over time.

Small changes in weight are normal. But losing weight without a clear reason might be a sign of a health problem.

It is important to see your doctor or nurse if you are not trying to lose weight and you lose more than 5 percent of your body weight over 6 to 12 months. An example is a person who weighs 150 pounds (68 kg) losing about 8 pounds (4 kg) over a year without trying to.

What can cause unexpected weight loss?

There are many possible reasons why a person might lose weight without trying. Examples include:

• Lifestyle changes – Things like stress, eating fewer calories than your body needs, intense exercise, or increasing your activity level can all lead to weight loss.

• Getting older – As you get older, you might have changes in taste or appetite. You are also more likely to have medical conditions or take medicines that can cause weight loss. It is also normal to lose some muscle as you age.

• Problems that affect eating – Things like poor appetite, trouble chewing or swallowing, dental problems, or nausea and vomiting can all lead to weight loss.

• Some medicines, natural products, or non-prescription drugs – They might reduce your appetite, cause nausea, or affect how your body absorbs nutrients from food. Examples include:

  • Medicines to treat diabetes, seizures, or thyroid problems

  • Caffeine

  • Nicotine

  • St. John's wort

  • Ephedra

• Medical conditions or treatments– Some medical conditions can affect your weight. Examples include:

  • Overactive thyroid

  • Digestion problems and infections

  • Cancer or cancer treatments, like radiation or chemotherapy

  • Mental health problems like anxiety, depression, or eating disorders

  • Heart, lung, or kidney problems

  • Autoimmune conditions like arthritis or lupus

• Drug or alcohol use – Using alcohol or drugs like cocaine, marijuana, or amphetamines can cause weight loss.

Will I need tests?

Maybe. Your doctor will start by asking about your weight loss and doing an exam. They might also do blood tests or other tests based on what they think might be causing your weight loss.

How is unexpected weight loss treated?

The right treatment depends on what is causing the weight loss. Treatment might include:

• Treatment for a medical condition

• Improving your nutrition – The doctor or nurse might suggest you meet with a dietitian (food expert).

• Reviewing or changing your medicines – Do not stop or change your medicines without talking with your doctor or nurse.

Your doctor might not be able to find a cause for your weight loss. They will want to follow up with you to monitor your weight.

What can I do on my own?

You might not be able to do anything. But if you think your weight loss was caused by your diet or lifestyle habits, you can try to take in more calories in your diet.

Eating foods with a lot of calories and protein can help keep your weight up. Some examples are:

• Thick soups

• Milk, milkshakes, cheese, pudding, and smoothies

• Nutritional supplement drinks (sample brand names: Ensure, Boost, Carnation Instant Breakfast)

• Eggs, chicken, lean red meat, and fish

• Yogurt, frozen yogurt, and ice cream

• Peanut butter, nuts, dried fruit, and granola bars

You can also:

• Eat 5 to 6 small meals a day, instead of 3 large meals. Eat healthy snacks in between meals when you feel hungry.

• Add butter, oil, nuts, gravy, powdered milk, protein powder, or cream to foods to give them extra calories and protein.

• Drink fluids between meals instead of with meals, so you do not fill up on fluids.

• Eat with family or friends.

• Take a short walk about an hour before you eat to help work up an appetite.

• Talk to your doctor if you have side effects from your medicines or treatments that are preventing you from eating.

When should I call the doctor?

Call for advice if:

• You cannot keep any foods or drinks down.

• You have severe belly pain.

• You feel dizzy or weak.

• You have a fever of 100.4°F (38°C) or higher.

• You think a medicine is causing your weight loss.