Weight Management Weight Loss Decreased Appetite and Unexplained Weight Loss in Men By Jerry Kennard, PhD Jerry Kennard, PhD Jerry Kennard, Ph.D., is a psychologist and associate fellow of the British Psychological Society. Learn about our editorial process Updated on June 14, 2021 Fact checked Verywell Fit content is rigorously reviewed by a team of qualified and experienced fact checkers. Fact checkers review articles for factual accuracy, relevance, and timeliness. We rely on the most current and reputable sources, which are cited in the text and listed at the bottom of each article. Content is fact checked after it has been edited and before publication. Learn more. by Adah Chung Fact checked by Adah Chung LinkedIn Adah is an occupational therapist, working in the area of pediatrics with elementary students with special needs in the schools. Her work as an occupational therapist includes: home health, acute care, chronic care, seating and positioning, outpatient rehab, and skilled nursing rehab. Learn about our editorial process Print Nico De Pasquale Photography / Getty Images Table of Contents View All Table of Contents Decreased Appetite Unexplained Weight Loss When to Seek Help If you're a man who has noticed that your appetite has decreased or you've lost weight for no apparent reason, there are many potential causes. While some may resolve on their own, others might require additional treatment. Knowing what to look for can help you decide when to seek help. Causes of Decreased Appetite The first step in managing a diminished appetite is determining the cause. Consider whether any of these conditions or issues might be affecting your appetite or eating habits, and discuss them with your healthcare provider. Emotional State Appetite can decrease in times of emotional upset. This includes periods when you may feel depressed, bored, or anxious. A reduction in appetite can also be caused by stress and the effect that it has on the brain's frontal pole. Illness or Infection Developing an illness or infection can also lead to a decrease in appetite, either directly or due to feeling nauseous. Infections that are often associated with a reduced desire to eat include: Respiratory infections that affect the lungs Pneumonia Influenza Kidney infection, such as pyelonephritis Hepatitis and conditions that cause liver inflammation HIV/AIDS Medical Conditions In some cases, loss of appetite may be caused by a physical health condition. Medical conditions that have been known to reduce one's appetite include: Amyotrophic lateral sclerosis (ALS) Appendicitis (26% of males have loss of appetite with appendicitis compared to 14.5% of females) Congestive heart failure Digestive disorders such as irritable bowel syndrome (IBS), Crohn's disease, celiac disease, and colitis Gastroesophageal reflux disease (GERD), also known as acid reflux Intestinal blockage Some cancers Nutrient Excess or Deficiency If your blood doesn't have enough of the minerals it needs, your appetite may be reduced. One example of this is hypokalemia, or low potassium in the blood, which can be caused by severe diarrhea, vigorous exercise, or the use of diuretics. Appetite can also decrease if you have too much of a specific mineral. If you have hypercalcemia—which is a condition in which there is too much calcium in the blood—you may notice a decrease in your desire to eat. Allergies and Sinus Conditions More than 50 million Americans have some type of allergy. Sometimes it's an allergy to something outdoors (such as trees, grass, or weed pollen). Other times, the person might be allergic to something indoors (mold, cat dander, or mites). Allergies can trigger the sinuses to release more mucous. When this mucous drains into your stomach, it can make you feel nauseous and reduce your appetite. Food Poisoning If you get food poisoning, you may not want to eat for a bit. Your stomach will likely be upset, potentially making it hard to keep food down until it starts to feel better. This can take hours to days after eating an unsafe food. Some studies have even connected certain insecticides with instigating a type of food poisoning, ultimately impacting appetite. While this is rare, choosing organic fruits and vegetables can help limit this risk. Medications Some medications are designed to suppress appetite. Others have appetite suppression as an additional, unintended side effect. Medicines that fall into the latter category include: Antibiotics Attention deficit and hyperactivity disorder (ADHD) medications Cancer treatments, such as chemotherapy Opiates (codeine, oxycodone, morphine) 10 Ways to Enjoy Food When Medication Suppresses Your Appetite Illegal Drugs Taking certain illicit drugs can also cause one's appetite to decline. Drugs that can potentially have this effect include hallucinogens, inhalants, and lysergic acid diethylamide (LSD). Other Causes There are a few additional factors that can potentially decrease a man's appetite. Among them are: Acute pain Migraine headaches High alcohol intake, especially over long periods of time Causes of Unexplained Weight Loss During periods of decreased appetite, weight loss can obviously occur. But there are occasions when weight loss is unexplained and may be unrelated to decreased appetite. One potential explanation is that the intake of calories is insufficient and outstripped by the energy needs of the body. Dramatic weight loss can also be due to an inability to digest and absorb food properly. Malabsorption is the term used to describe this inability of the body to absorb enough nutrients from the consumption of food and drink. This can lead to malnutrition and unexplained weight loss. The most common nutrients not sufficiently absorbed are fats (lipids); however, malabsorption can apply to nutrients like carbohydrates and proteins, minerals like iron and calcium, vitamins, and electrolytes like potassium and sodium. Malabsorption can be caused by several factors, including: Digestive enzyme problems Drug abuse Fever Gallbladder problems Hyperthyroidism Parasitic infections Small intestine problems Some medications causing long-term diarrhea When to Seek Help If your loss of appetite is accompanied by depression, an eating disorder, and/or drug or alcohol use, talk to your doctor. Seeking help is also recommended if you have any other symptoms that are unexplained. This can help rule out a medical condition. When weight loss reaches more than 10% of your starting weight over a short period of time (3 months, for example), medical attention is required to search for medical causes. What Is Appetite? Definition and How to Increase It 23 Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Simmons WK, Burrows K, Avery JA, et al. Depression-related increases and decreases in appetite: Dissociable patterns of aberrant activity in reward and interoceptive neurocircuitry. Am J Psychiatry. 2016;173(4):418-428. doi:10.1176/appi.ajp.2015.15020162 Nakamura C, Ishii A, Matsuo T, et al. Neural effects on acute stress on appetite: a magnetoencephalography study. PLoS One. 2020;15(1):e0228039. doi:10.1371.journal.pone.0228039 Bosch X, Monclús E, Escoda O, et al. Unintentional weight loss: Clinical characteristics and outcomes in a prospective cohort of 2677 patients. PLoS One. 2017;12(4):e0175125. doi:10.1371/journal.pone.0175125 Holm T, Maier A, Wicks P, et al. Severe loss of appetite in amyotrophic lateral sclerosis patients: online self-assessment study. Interactive J Med Res. 2013;2(1). doi:10.2196.ijmr.2463 Barisik C, Bener A. Predictors risk factors for acute complex appendicitis pain in patients: Are there gender differences? 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The malabsorption syndrome and its causes and consequences. Pathobiol Hum Dis. 2014;1266-1287. doi:10.1016/B978-0-12-386456-7.03804-1 Daher R, Yazbeck T, Jaoude JB, Abboud B. Consequences of dysthyroidism on the digestive tract and viscera. World J Gastroenterol. 2009;15(23):2834-2838. doi:10.3748/wjg.15.2834 Mount Sinai. Appetite - decreased. Cleveland Clinic. Unexplained weight loss. By Jerry Kennard, PhD Jerry Kennard, Ph.D., is a psychologist and associate fellow of the British Psychological Society. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit