Loss of Weight – UpToDate

Loss of Weight
  • Clinically important weight loss is traditionally defined as loss of more than 5 percent of usual body weight over six months.

Major causes of weight loss

1) Voluntary weight loss
  • Drugs
    • Rx ↓ obesity: rimonabant, orlistat, phentermine, sibutramine, metformin, bupropion
    • Rx abuse for weight loss effects: amphetamines and derivatives, thyroid hormone
    • Herbal & OTC: 5-hydroxytryptophan, aloe, caffeine, cascara, chitosan, chromium, dandelion, ephedra, garcinia, glucomannan, guarana, guar gum, herbal diuretics, nicotine, pyruvate, St. John’s wort
  • Dieting
  • Anorexia nervosa and bulimia nervosa
  • Chronic vigorous exercise, usually combined with dieting (eg, distance runners, ballet dancers, gymnasts)
2) Involuntary weight loss with increased appetite
  • Hyperthyroidism
  • Uncontrolled diabetes mellitus
  • Malabsorption syndromes
  • Marked increase in physical activity
3) Involuntary weight loss with decreased appetite
  • Medical disorders
    • Malignancy: particularly gastrointestinal, lung, lymphoma, renal, and prostate cancers
    • GI: PUD, malabsorption, diabetic enteropathy, dysphagia, IBD, hepatitis, Zenker’s diverticulum, paraesophageal hernia
    • Endo: hyperthyroidism, diabetes, adrenal insufficiency
    • ID: HIV, viral hepatitis, TB, chronic fungal or bacterial disease, chronic helminth infection, lung abscess
    • Severe heart, lung, or kidney disease:
      • cardiac cachexia from heart failure
      • pulmonary cachexia from severe obstructive or restrictive lung disease
      • renal failure, nephrotic sydrome, chronic glomerulonephritis
    • Neuro: stroke, dementia, dysphagia, Parkinson disease, amyotrophic lateral sclerosis
    • Chronic inflammatory:  sarcoidosis, severe RA, giant cell vasculitis
  • Psychiatric disorders
    • Affective disorders: depression, bipolar disorder, GAD
    • Food-related delusional manifestations of other psychiatric disorders
  • Drugs
    • Alcohol
    • Opiates
    • Amphetamines and cocaine
    • Drug withdrawal syndromes: withdrawal after chronic high-dose psychotropic medications or cannabis
    • Adverse effects of Rx: topiramate, zonisamide, SSRIs, levodopa, digoxin, metformin, exenatide, liraglutide, NSAIDS, and anticancer and antiretroviral drugs
    • Herbal and other nonprescription drugs (see above)

1  Pursue an underlying cause in a patient with unexplained weight loss through history, physical examination (including weight) and appropriate investigations.

  1. The duration and pattern of weight loss
    • past fluctuations in weight
    • whether weight loss is progressive or stabilized.
    • Weight loss in a person whose weight has been stable and weight loss that is progressive are more worrisome and require more immediate follow-up.
  2. Intention to lose weight, changes in appetite, caloric intake, and physical activity.
  3. Furthermore, the interviewing clinician should elicit medical, psychological, and functional factors associated with poor food intake. The nine D’s associated with weight loss may help elicit these factors, particularly in the elderly:
    • Dentition
    • Dysgeusia
    • Dysphagia
    • Diarrhea
    • Depression & Dementia
    • Disease & dysfunction
    • Drugs
  4. A thorough review of systems is necessary if the etiology remains uncertain after the above questioning.
Physical examination
  • assess the overall appearance, affect, skin changes (eg, melanoma or spider angiomata), presence of lymphadenopathy, cardiopulmonary status, hepatosplenomegaly, abdominal mass, breast/prostate abnormalities, rectal examination with stool hemoccult, and any neurologic deficit.
    • abnormal physical findings were common among those with malignancy
    • Conversely, abnormal physical findings were present in only 3 percent of those diagnosed with a psychiatric disorder or who remained undiagnosed after a thorough evaluation and follow-up.
Diagnostic testing
  • + Hx / PEx: Ix focused on confirming the suspected dx
  • – Hx / PEx:  a basic Ix should include:
    • Lab:
      • CBCD & hemoglobin A1c & ESR or CRP
      • chemistries: electrolytes, glucose, calcium, renal and hepatic function, TSH
      • U/A, FOB
    • Diagnostic imaging: CXR
  • Despite an appropriate initial evaluation, a clear cause for weight loss is often not found. Watchful waiting for one to six months is preferable to a battery of testing with low diagnostic yield


2  Maintain an ongoing record of patients’ weights so as to accurately determine when true weight loss has occurred.

Qualitative judgments by patients about the magnitude of their weight loss are often unreliable.

In a prospective study of involuntary weight loss, only 50 percent of patients reporting weight loss had true weight loss. Therefore, in documenting weight loss, it is important to obtain previous weight records and, if not available, to query family members about the patient’s weight history, including usual weight prior to the period of weight loss

3  In patients with persistent weight loss of undiagnosed cause, follow-up and reevaluate in a timely manner in order to decide whether anything needs to be done.

  • careful attention should be paid to dietary history, possibility of psychosocial causes, surreptitious drug intake, and new manifestations of occult illness.
  • pharm. Tx: infections, endocrinopathies
  • surgery/radiation: malignancy
  • behavioral therapy:depression, anorexia nervosa
  • removal of offending agents: ephedra, laxatives
  • nutritional support: dementia, dysphagia

  • UpToDate 2015
Posted in 60 Loss of Wt, 99 Priority Topics, Endo, FM 99 priority topics

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