8 Sudden Weight Loss Causes in Men & Women (Causes of Unexplained Weight Loss)

Here are the top 8 causes for sudden weight loss in men and women.

  1. Mental Health
  2. Digestive Issues
  3. Infections
  4. Medications
  5. Drug and Alcohol Use
  6. Chronic Disease
  7. Hormone Imbalances 
  8. Swallowing or Eating Issues 

Nutrition and food intake is central to our wellbeing and lives, so there are many factors that can impact our body weight. More often than not, we are trying to lose weight and pay close attention to our food choices and how to control our appetite and hunger. But if you find that you are losing weight without trying, this could be a symptom of something else. 

How much weight have you lost? Should you be concerned? In this article we’ll explore some of the many things that could cause unexplained weight loss and when you should consider seeing a doctor. 

What is Sudden Weight Loss and Why Does it Matter? 

Sudden weight loss occurs when you lose weight without changing your diet or fitness routine. It can also be defined by an unexplained weight loss of 5% or more of your body weight in 6 to 12 months (1,2). This would equal out to be around a 10 pound weight loss in a 200 pound adult. 

Sudden weight loss can happen to anyone, but is more prevalent in adults over the age of 65 (3,4,5,6).

It is normal for your weight to fluctuate from time to time, but major changes in your bodyweight are different. A significant amount of weight loss may be cause for concern because it can also indicate an underlying health concern or medical condition that needs attention. It can also lead to malnutrition, muscle loss, and decreased wellness if it continues to occur long term. 

What is the Most Common Cause of Sudden Weight Loss?

It is hard to pinpoint exactly what might causes weight loss unexpectedly in most people because there are a large number of possible factors (1). Some less serious, yet more common possibilities include any changes in mental health and changes in digestion (7,8). 

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It is also possible that you are unintentionally losing weight through healthy habits like physical activity. Most people do not accurately track their food intake well enough to spot small changes in their diet that can result in “unexplained weight loss”. 

For example, switching to a new lunch restaurant that happens to use less oil in their recipes or eating fewer snacks throughout the day without realizing it, can add up to very meaningful calorie decreases over time.

8 Causes of Sudden Weight Loss in Men and Women

It is important to note that any changes to your health should be discussed with your primary physician and this list is not intended to help you self diagnose or treat anyone suffering from unexplained weight loss. 

Some causes of unintentional weight loss include: 

1. Mental Health

Mental health is a big factor and the onset of depression, anxiety, or an eating disorder can all interfere with one’s nutrition habits. Additionally, stressful life events like the loss of a job, a divorce, or the death of a family member can all cause one to decrease their food intake and lose weight without realizing it. 

  • Stress
  • Anxiety
  • Depression
  • Eating Disorder
  • Dementia

2. Digestive Issues

Changes to your digestive system caused by inflammation, infection, damage to your intestine lining, or the onset of a digestive disorder are a direct link to how you digest and metabolize your food (9,10). Any of the following digestive issues can cause you to lose weight: 

  • Irritable Bowel Disease IBD
  • Celiac Disease
  • Crohn's Disease
  • Ulcers
  • Ulcerative Colitis

3. Infections

Depending on the type, certain infections can directly impact your metabolic rate, while others can directly interfere with absorption of nutrients. Types of infections that can cause you to lose weight are: 

  • Parasitic Infection
  • Rheumatoid arthritis
  • Tuberculosis
  • HIV

4. Medications

Certain prescribed medications can increase metabolic rate causing you to lose weight more quickly. Other medications can mess with your desire to eat with increased nausea, dyspepsia, or dysgeusia (11). These medications can include: 

  • Antibiotics
  • Anticonvulsants
  • Antidiabetics
  • Antifungals
  • Acetylcholinesterase inhibitors
  • Sedatives
  • Serotonin reuptake inhibitors
  • Tyrosine kinase inhibitors
  • Chemotherapy
  • Radiation Therapy
  • Disease-modifying antirheumatic drugs

5. Drug and Alcohol Use

Outside of prescribed medications, drug and alcohol use can also interfere with your metabolism (12). This can include just about any form of alcohol or illegal substance and depends on the amount and frequency of use. 

6. Chronic Disease

There are a wide range of chronic diseases and forms of chronic inflammation that can also impact your nutrition and weight status (13). These include: 

  • Diabetes
  • Cancer
  • Parkinson’s Disease
  • Rheumatoid Arthritis
  • COPD
  • Heart Failure
  • Endocarditis
  • Parkinson’s Disease
  • Type 1 Diabetes
  • Autoimmune Disease
  • Tumor

7. Hormone Imbalances

Certain hormonal imbalances can directly impact your appetite and nutrient metabolism (14). Causes of hormonal imbalances that can lead to weight loss are: 

  • Overactive Thyroid Gland (Hyperthyroidism)
  • Addison’s Disease
  • Adrenal Glands Insufficiency (changes in aldosterone and cortisol)
  • Exocrine pancreatic Insufficiency (decreased ability of the pancreas to produce digestive enzymes)

8. Swallowing or Eating Issues

Physical impairment, such as difficulty swallowing or pain while eating will definitely impair one’s ability to consume enough calories. This can include: 

  • Dysphagia
  • Dental Problems

When Should You See a Doctor About Sudden Weight Loss?

Weight loss can be caused by many factors that impede your desire or physical ability to eat enough food. Or perhaps you just need to pay closer attention to your nutrition intake to discover the cause. 

Sudden weight loss is not always room for concern, but it is almost always best to discuss with your doctor before drawing any conclusions Especially if you notice any additional symptoms that are concerning to your health. Symptoms like loss of appetite or poor appetite, diarrhea, low blood sugar, and depression may be a sign of something else your doctor may need to treat. 

Some other symptoms you may experience include: 

  • Fatigue
  • Changes in stool or urine
  • Changes in bathroom habits
  • Changes in appetite
  • Changes in mental status
  • You may also feel pain or discomfort in the body (joint pain, abnormal fullness, etc.)

Diagnosing and Treating Sudden Weight Loss

Your doctor is your best ally in diagnosing and treating any causes of sudden weight loss and necessary weight gain. Through a physical exam, blood test, urine and stool samples, and any other test needed, your physician can help you discover why you are losing weight and proper treatment options. 

In the meantime, you can focus on your nutrition by learning how many calories you need to eat a day to maintain your current weight, and by tracking your nutrition to ensure you are getting enough food each day. 

Set yourself up for success with tasty, ready to eat recipes that make it hard to skip a meal. Trifecta will cook and ship nutritious food right to your door!