What is the appropriate workup for weight loss?

Workup for Weight Loss

The appropriate workup for weight loss must first distinguish between intentional and unintentional weight loss, as unintentional weight loss requires a comprehensive medical evaluation to identify potentially serious underlying causes. 1

Initial Assessment for Unintentional Weight Loss

History

• Quantify weight loss: amount, timeframe (significant if >5% over 6-12 months)
• Dietary changes: appetite, food intake, difficulty swallowing, taste changes
• Gastrointestinal symptoms: nausea, vomiting, diarrhea, constipation, abdominal pain
• Systemic symptoms: fever, night sweats, fatigue
• Psychological assessment: depression, anxiety, cognitive changes
• Medication review: new medications, polypharmacy
• Social history: living situation, ability to obtain/prepare food, alcohol use
• Review of systems: focusing on all major organ systems

Physical Examination

• Vital signs including temperature
• Comprehensive examination with focus on:
  • Oral cavity (dentition, mucosa)
  • Thyroid
  • Cardiopulmonary system
  • Abdominal examination (masses, organomegaly)
  • Lymph nodes
  • Neurological assessment (including cognitive function)
  • Skin (cachexia, lesions)

Laboratory and Diagnostic Testing

First-Line Tests

• Complete blood count
• Comprehensive metabolic panel
• Thyroid-stimulating hormone
• Urinalysis
• Fecal occult blood test
• C-reactive protein/erythrocyte sedimentation rate
• HbA1c (if diabetes suspected)

Second-Line Tests (Based on Initial Findings)

• Chest X-ray
• Upper GI endoscopy (especially in elderly with GI symptoms)
• Abdominal imaging (ultrasound, CT scan)
• HIV testing (if risk factors present)
• Tuberculosis testing
• Additional endocrine workup (cortisol, etc.)
• Age-appropriate cancer screening

Common Causes of Unintentional Weight Loss

In Community-Dwelling Adults

• Malignancy (especially lung and gastrointestinal)
• Non-malignant gastrointestinal disorders
• Psychiatric disorders (depression, anxiety)
• Endocrine disorders (hyperthyroidism, diabetes)
• Infectious diseases
• Medication side effects

In Institutionalized Older Adults

• Psychiatric disorders (depression most common)
• Difficulty feeding self
• Swallowing disorders
• Dementia-related factors
• Social factors (isolation, lack of preferred foods)

Management Approach

1. Treat identified underlying causes
2. Nutritional support:
   • Dietary consultation
   • Calorie-dense supplements
   • Consideration of appetite stimulants in select cases
3. Address environmental and social factors:
   • Ensure adequate assistance with meals if needed
   • Provide preferred foods
   • Create pleasant eating environment
4. Follow-up:
   • Close monitoring for patients without identified cause (up to 25% of cases)
   • Regular weight checks
   • Reassessment if weight loss continues

Special Considerations for Elderly Patients

Elderly patients with unintentional weight loss have higher risk for infection, depression, and death 2. Special attention should be paid to:

• Medication review (polypharmacy is common)
• Dental health and swallowing function
• Cognitive assessment
• Social support evaluation
• Nutritional needs and preferences

Intentional Weight Loss Evaluation

For patients seeking intentional weight loss, assessment should include:

1. BMI calculation and waist circumference measurement 3
2. Obesity-related comorbidity screening:
   • Hypertension
   • Dyslipidemia
   • Diabetes/prediabetes
   • Sleep apnea
   • Fatty liver disease
   • Osteoarthritis
3. Readiness for change assessment
4. Previous weight loss attempts and outcomes
5. Psychological factors affecting eating behaviors

Key Pitfalls to Avoid

• Failing to distinguish between intentional and unintentional weight loss
• Missing malignancy as an underlying cause (particularly GI and lung)
• Overlooking depression, especially in elderly patients
• Assuming a diagnosis without appropriate testing
• Inadequate follow-up for patients without identified cause
• Focusing only on weight without addressing quality of life and function

Remember that up to 25% of patients with unintentional weight loss may not have a specific diagnosis after comprehensive workup, making close follow-up essential 1.