Causes of Weight Loss in the Elderly

Elderly man wearing a baseball cap.

Unintentional weight loss commonly impacts the elderly. 

27% of those >65 years old in the community and 60% living in nursing homes experience unintentional weight loss (1)

Weight loss in the geriatric population occurs for various reasons and can lead to many negative effects. Let’s explore these causes and their impact. 

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What is Unintentional Weight Loss?

Unintentional weight loss is the reduction of body weight that is involuntary. 

Centers for Medicare and Medicaid considers losses of 5% in 30 days, 7.5% in 90 days, and 10% in 180 days significant. 

Recovery from weight loss in the elderly is more difficult as the process to regain muscle is impaired with age (2)

Causes of Weight Loss

Multiple factors create increased risk for weight loss in the geriatric population. 

Causes of weight loss: chronic disease, acute illness, medications, physical declines, mood, physiological changes, anorexia of aging, fluid, oral problems, social factors, cognition.
Causes of Weight Loss in the Elderly

Chronic Diseases

Many chronic conditions contribute to weight loss as part of their disease processes (3). Some of these include: 


All types of cancer create increased nutritional needs due to the widespread impact on the body. This is in addition to the basic nutrient need requirements. 

Head, neck, and gastric cancers can put patients at even increased risk for weight loss. 

Their symptoms and treatments can cause increased difficulties eating. Feeding tubes may be warranted in some cases. 

Gastrointestinal Disorders

Anything affecting the Gastrointestinal (GI) tract is likely to poorly impact appetite and intake. 

Constipation can lead to fullness or nausea, decreasing intake and resulting in weight loss over time. 

Irritable bowel syndrome (IBS), colitis, or general diarrhea create risk for dehydration. Some become fearful of eating and avoid it so foods don’t “run through them.” 

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*This article contains affiliate links. I may earn a commission from qualifying purchases at no extra cost to you. 

Ulcers, GI bleed, and other problems causing abdominal pain can lead to reduced food intake. 

Other GI disorders that can lead to weight loss include gastroparesis (delayed stomach movement), vomiting, GERD (gastroesophageal reflux), and hiatal hernias.


Dysphagia is difficulty swallowing. Self limiting of foods may occur, consuming only soft foods for ease of swallowing. 

Altered foods and thickened liquids are used to improve the safety of swallowing. Some may dislike these altered textures, leading to poor intake and weight loss. 

Celiac Disease

Celiac disease is when an immune response occurs in the small intestine when gluten is eaten. Gluten is a protein found in wheat, barley, and rye. 

Because of the impact on the GI tract, weight loss can occur until gluten is removed from the diet and the small intestine recovers. 

A gluten free diet may be difficult to follow for older adults who don’t have as much access to foods or when cognition is impaired. 

Even Amazon has tons of gluten free products for delivery right to your house.

*This article contains affiliate links. I may earn a commission from qualifying purchases at no extra cost to you. 

Thyroid Disorders

Hyperthyroidism occurs when there is an overproduction of thyroid hormones. The elderly typically present with fatigue and weight loss. 

Hypothyroidism occurs when the thyroid gland is functioning less than normal. Weight gain is a common symptom. 

However, abnormalities in thyroid levels can lead to altered taste and cognitive impairment. These symptoms can lead to reduced nutritional intake. 

Thyroid hormone controls metabolism, so any disturbances can negatively affect nutritional status. 


Although energy needs may reduce with age, vitamin and mineral needs do not. Following a strict diabetic diet can lead to inadequate intake and weight loss. 

Unstable blood sugars impact metabolism and cause weight loss as well. 

Human Immunodeficiency Virus

HIV compromises the immune system and increases nutritional needs. If these needs are not met then weight loss can occur.

HIV treatment has become so effective, however, that this risk is decreased with proper medication regimen. 

Parkinson’s Disease

Parkinson’s disease is a brain disorder causing involuntary movements, stiffness, and poor coordination. 

Its disease process can lead to dysphagia and unavoidable weight loss. 

Depression & Anxiety

Depression and anxiety can plague the elderly population for a variety of reasons.

Isolation, grief, decreased independence are just a few examples. This can all lead to a lack of desire to eat and then weight loss. 


Dementia is a progressive cognitive decline, which can result in decreased physical function.

Dementia impacts many processes involved in appetite and eating. This can lead to decreased intake and poor absorption of nutrients. 

Multiple factors in its disease process can cause weight loss. 

Acute Illness

Acute illness can cause temporary decline in appetite and lead to weight loss. 

Some common conditions that occur in the elderly are:

Pain and treatments for acute illness can lead to poor appetite. Many antibiotics cause stomach upset which poorly affects appetite. 

This typically resolves when illness is over, however some may find it difficult to regain lost weight.  


Medications frequently have nutrition related side effects (4):

  • Reduced salivation
  • Dry mouth
  • Taste changes/loss
  • Decreased appetite
  • Constipation
  • Diarrhea
  • Nausea 
  • Lethargy

These side effects can all impact nutritional status and/or ability to eat, leading to weight loss. 

Other medications may lead to fluid related weight loss, such as diuretics (water pills).  

Polypharmacy is when multiple medications are used for the same condition or when one person takes many medications. This is common in the elderly. 

The more medications used, means greater potential for the above side effects that can impair nutrition and lead to weight loss. 

Nutrition side effects of medications: reduced salivation, dry mouth, taste changes, loss of taste, decreased appetite, constipation, diarrhea, nausea, lethargy, fluid shifts, dehydration.
Nutrition Side Effects of Medications

Physical Declines

Both acute and chronic conditions can lead to physical declines in the elderly. 

Fractures can impair mobility. Other chronic conditions, such as Parkinson’s alters balance and coordination. 

Decreases in ADLs (activities of daily living) can cause depression due to loss of independence. Self feeding may be more difficult also. 

Decreased ability to get to the grocery store and prepare meals can lead to poorer nutrition. 


The geriatric population faces many challenges that impact mood including:

  • Social isolation
  • Grief, especially loss of spouse  
  • Decreased independence
  • Placement into institutions

Poor mood can inhibit intake causing weight loss. 

Physiological Changes

Changes in gastric signals leads to early fullness and therefore less nutritional intake (5). This includes slowed stomach emptying

Sense of smell and taste is reduced, which also can inhibit adequate eating. 

Anorexia of Aging

Anorexia of aging is the age-related decline in appetite. Motivation to eat is diminished even when illness is not present. 

This leads to inadequate nutritional intake and then weight loss. 

Learn more at Appetite Loss in the Elderly.  

Oral Problems

The elderly face many oral issues. This includes poor dentition, missing teeth, ill fitting dentures, and swallowing difficulty. 

This all can impact chewing and swallowing ability. Some may not voice their deficit and restrict foods instead. 

Altering diet textures, serving naturally soft foods, and receiving speech therapy can help. 

Routine oral care and dental visits can assist as well. 


Cognitive impairment can impact eating and weight in a variety of ways. Forgetting to eat, poor appetite, difficulty self feeding are a few examples. 

The impact on the brain from various conditions impacting cognitive function, such as dementia, can also cause impaired absorption regardless of adequate food intake. 

Social Factors

Losing a spouse, living in isolation, inability to get to the grocery store or prepare meals can lead to poor nutritional intake and weight loss. 

Many older adults live on a fixed income and even affording adequate nutrition can be difficult. 


Many chronic conditions impact fluid status, including kidney disease, congestive heart failure (CHF), liver cirrhosis, edema (swelling). 

These diagnoses will cause weight changes as fluids shift in the body.

Diuretics, water pills, are frequently prescribed for heart failure and edema which will cause fluid to be pulled from the body and create fluid related weight loss. 

Risks of Unintentional Weight Loss

Losing 4-5% body weight in one year or greater than 10% in five to ten years is linked with increased morbidity and mortality (6)

Maintaining weight is important to reduce associated risks (7), (8), (9):

  • Increased infections
  • Bone loss
  • Fractures
  • Hospitalization
  • Poor quality of life
  • Increased morbidity and mortality
  • Cachexia 
  • Fatigue 
  • Declined physical function 
  • Hospital related complications
Risks of weight loss: increased infections, bone loss, fractures, hospitalizations, poor quality of life, increased morbidity and mortality, cachexia, fatigue, declined physical function, hospital complications.
Risk of Weight Loss

Prevention and Treatment

Monitoring intake and weight trends can help identify the beginning of weight loss. 

Early identification and intervention can prevent weight loss before it becomes significant. 

Finding the root cause of weight loss can improve the success of interventions. 

Here are some ways to prevent and treat weight loss: 

  • Honor food and beverage preferences
  • Liberalize diet
  • Mechanically alter foods as appropriate
  • Thicken liquids if necessary
  • Serve more calorie dense foods
    • Add peanut butter
    • Add extra butter or margarine
    • Mix in powdered milk
    • Top with cheese
    • Liberally use condiments such as mayo, sour cream, and gravy
    • Use extra sauce 
  • Try oral nutrition supplements, ideally between meals
  • Offer snacks throughout the day
  • Keep foods and fluids visible 
  • Offer choices
  • Serve meals in social environment
  • Keep dining areas well light
  • Adjust portion sizes as needed: some may be overwhelmed by large meals
  • Try family style dining 
  • Allow adequate time to eat
  • Serve foods of contrasting colors 
  • Consult psychology when mood issues are present
  • Doctors may prescribe appetite stimulants when appropriate 
  • Treat gastrointestinal (GI) issues 
  • Tube feeding may be appropriate in some instances 

*This article contains affiliate links. I may earn a commission from qualifying purchases at no extra cost to you. 

Prevent & treat weight loss: honor food preferences, liberalize diet, mechanically alter foods, thicken liquids, serve calorie dense foods, supplements, snacks, keep foods visible, offer choices, social environment, well lit dining rooms, adjust portion sizes, family style dining, psych consult, med review.
Prevent and Treat Weight Loss

Practical Takeaways

Weight loss occurs in the elderly for a number of reasons from chronic conditions to social issues. 

Early identification and quick implementation of intervention can help stop or at least slow weight loss. 

Keeping weight loss at bay can help the elderly avoid the many complications associated with unintentional weight loss.

*This article contains affiliate links. I may earn a commission from qualifying purchases at no extra cost to you. 

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