Summary
Unintentional weight loss and/or malnutrition affect up to 10% of adults aged > 65 years. Conditions associated with unintentional weight loss and/or malnutrition can be classified as inflammatory (e.g., acute illness, COPD) or noninflammatory (e.g., dental disorders, major neurocognitive disorder, major depressive disorder). Diagnostic criteria of malnutrition identify significant weight loss, sarcopenia, and/or evidence of inflammation or decreased food intake and help confirm the diagnosis. Further clinical evaluation and diagnostic studies help identify an underlying cause and assess for complications. Management involves treatment of the underlying cause, nutritional support, and management of dehydration and/or micronutrient supplementation as needed.
Epidemiology
The prevalence of malnutrition varies significantly based on various factors (e.g., age, comorbidities).
- 5–10% in individuals aged > 65 years [1]
- Up to 50% in long-term care facilities (e.g., nursing home residents) [1][2]
- 20–50% in individuals with chronic conditions (e.g., COPD, congestive heart failure, Alzheimer disease) [1]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
Disease-related malnutrition with inflammation [1][2][3]
Includes conditions that increase metabolic demand and catabolism
-
Acute illness [4]
- Severe trauma
- Burns
- Severe infections
-
Chronic conditions
- Gastrointestinal disorders
- Cardiopulmonary conditions
-
Malignancy-related
- Cancer anorexia-cachexia syndrome (most commonly caused by GI tract cancer) [2][3]
- Chemotherapy-associated anorexia
- Endocrine disorders, e.g.:
- Chronic infections, e.g., HIV wasting syndrome, tuberculosis
- Autoimmune conditions, e.g., polyarteritis nodosa, polymyalgia rheumatica
- Other conditions, e.g., CKD, retroperitoneal fibrosis
Chronic conditions can lead to cachexia, a form of secondary protein-energy malnutrition associated with muscle catabolism despite nutritional supplementation.
Disease-related malnutrition without inflammation [1][2]
Includes conditions that cause difficulty swallowing and/or reduced oral intake
-
GI tract disorders
- Dental disorders
- Causes of esophageal dysphagia, e.g., ; esophageal strictures, esophageal carcinoma
- Short bowel syndrome [4]
- Neurological disorders (including causes of oropharyngeal dysphagia)
- Psychiatric conditions
-
Other causes
- Medications causing decreased food intake [3]
- Early postoperative state [5]
- Mechanical ventilation (See “Supportive care in the intensive care unit” for more information.) [6]
Anorexia nervosa is not classified as a cause of unintentional weight loss, but it is a common cause of malnutrition in adults.
Malnutrition without disease [1][2]
Causes of inadequate access to nutritious food (i.e., food insecurity) include:
- Individual socioeconomic situation
- Low food availability (e.g., during natural disasters)
Malnutrition and unintentional weight loss in older adults are often multifactorial; a cause is not identified in up to one-third of cases. [3][7]
The causes of weight loss in older adults can be summed up in 9 Ds: dementia, depression, disease, disability, diarrhea, drugs, dysphagia, dysgeusia, and dentition. [3]
Screening
Nutritional assessment in older adults [2][8]
- Consider annual screening.
- Screening options
- Monitor weight and/or BMI.
- Ask the patient if they have lost weight in the last 6–12 months.
- Mini Nutritional Assessment
- Any of the following are considered a positive screen and should prompt further evaluation:
- BMI < 23 kg/m2
- Unintentional loss of ≥ 5% of weight in 6–12 months
- Mini Nutritional Assessment score ≤ 11
A BMI < 23 kg/m2 is associated with increased mortality in older adults. [9]
Screening for malnutrition in hospitalized patients [1][2][10]
- Screen all patients within 48 hours.
- Use of screening tools is recommended, e.g., Nutritional Risk Screening 2002.
Clinical evaluation
Focused history [1][3]
-
Current medical history
- Onset, duration, and amount of weight loss
- Appetite, oral intake, and diet
- Changes in muscle mass and strength
- Symptoms of micronutrient deficiencies (e.g., vitamin deficiencies, zinc deficiency)
-
Past medical history
- Diagnosis of a cause of malnutrition and unintentional weight loss in adults
- Medication review: drugs associated with decreased food intake
-
Social history
- Access to food: socioeconomic status, living situation, social support
- Assessment of social situation for older adults
-
Symptoms of underlying conditions
- Constitutional symptoms
- GI tract symptoms (e.g., dysphagia, changes in bowel habit)
- Psychiatric symptoms (e.g., depressed mood, symptoms of cognitive impairment)
Following presentation with unintentional weight loss, 1 in 10 adults aged > 60 years are diagnosed with cancer. [3]
Focused physical examination [1][3]
- General appearance: Assess for features of dehydration or hypovolemia.
-
Body measurements
- Measure body weight and BMI.
- Assess fat mass (e.g., using waist circumference).
- Assess for reduced muscle mass (e.g., calf circumference, mid-upper arm circumference).
-
Features of underlying conditions [3]
- Functional status assessment, including mobility
- Oral cavity examination (e.g., tooth decay, problems with dentures)
- Cardiovascular examination (e.g., clinical features of heart failure)
- Pulmonary examination (e.g., clinical features of pneumonia, clinical features of COPD)
- Abdominal examination (e.g., clinical fatures of celiac disease, clinical features of colorectal cancer)
- Neurological examination (e.g., for clinical features of major neurocognitive disorder)
Diagnosis
Approach [3]
- Perform a detailed clinical evaluation.
- Use the diagnostic criteria for malnutrition in adults to:
- Confirm diagnosis
- Establish severity based on phenotypic criteria [4]
- Obtain initial studies to assess for:
- Underlying causes of malnutrition
- Associated conditions (e.g., micronutrient deficiencies)
- Consider additional studies based on clinical judgment.
- Refer all patients for specialist nutritional evaluation.
Diagnostic criteria for malnutrition in adults [1][4]
| Global Leadership Initiative on Malnutrition criteria [4] | |||
|---|---|---|---|
| Phenotypic criteria |
| ||
| |||
| Etiologic criteria |
| ||
| The diagnosis of malnutrition is appropriate if one phenotypic criterion and one etiologic criterion are met. | |||
Initial studies
Laboratory studies [1][12]
- CBC: to evaluate for anemia (e.g., caused by micronutrient deficiencies, malignancy), lymphopenia [12]
-
CMP
- Electrolytes: to evaluate for hyponatremia (e.g., due to severe dehydration), hypercalcemia of malignancy
- Fasting plasma glucose: to evaluate for underlying diabetes mellitus
- Thyroid function tests: to rule out hyperthyroidism
- Inflammatory markers: to evaluate for underlying inflammatory disease [1]
- Micronutrient levels: to evaluate for deficiencies (e.g., vitamin B1, vitamin B6, vitamin B12, folic acid, iron, and/or zinc deficiencies)
Albumin is not recommended as a marker of malnutrition. [1][2]
Chest X-ray [12]
- Indication: all individuals > 65 years of age
- May show signs of an underlying condition, e.g.:
Cancer screening
- Obtain fecal occult blood test in all older adults and patients with relevant clinical features (e.g., changes in bowel habit). [3]
- Perform further cancer screening as indicated based on the patient's age and sex.
Additional studies
- Abdominal ultrasound: Consider as initial test in patients with features of GI disorders (e.g., abdominal pain, early satiety, change in stool pattern). [3]
- CT abdomen, thorax, or pelvis: for suspected malignancy
- Endoscopy: e.g., for suspected esophageal dysphagia
- Modified barium swallow: for suspected oropharyngeal dysphagia
- Serology: e.g., HIV screening if risk factors for HIV; HCV screening if risk factors for HCV infection
Management
General principles
- Involve a specialist team (e.g., nutritionist, physiotherapist, social services) for all patients.
- Treat the underlying condition and consider specialist referral. [1]
- If no cause is established: close observation and reassessment in 3–6 months [3]
- Provide nutritional support.
- Manage dehydration and nutritional deficiencies as indicated.
- Indications for specialized nutrition support may be considered. [1]
- For patients with severe malnutrition, see also “Prevention of refeeding syndrome.”
Nutritional support [1][2][3]
- Optimize oral intake
- Ensure adequate access to food (e.g., through meal delivery services).
- Food preparation and mealtimes
- Recommend smaller, more frequent meals with varied, appealing foods.
- Encourage eating with others. [13]
- Adapt food texture (e.g., softer foods if swallowing and/or dental disorders).
- Recommend assistance at mealtimes if required.
- Avoid appetite stimulants (e.g., megestrol) in most patients, especially older adults. [3][14]
- Oral nutritional supplements may be considered in patients with either of the following: [2][15]
- Inability to increase caloric intake with foods
- Current or recent hospitalization
Do not routinely prescribe appetite stimulants or high-calorie supplements to improve appetite or increase weight in older adults. [16]
Assistance at mealtimes is recommended in patients with advanced major neurocognitive disorder; avoid invasive enteral or parenteral feeding. [16]
Management of dehydration and nutritional deficiencies
Consider specialist referral and/or hospital admission as indicated.
- Management of dehydration
- Electrolyte repletion
- Micronutrient supplementation (e.g., oral iron therapy, thiamine and/or zinc supplementation) [17]
Complications
- Sarcopenia
- Immunocompromise-related infections (e.g., pneumonia, gastroenteritis, urinary tract infection, sepsis)
- Impaired wound healing
- Secondary osteoporosis, stress fractures
- Frailty
- Impaired mobility and falls
Malnutrition leads to deterioration in overall functioning and worsens clinical outcomes of other health conditions. [1]
We list the most important complications. The selection is not exhaustive.