Physical and Systemic Effects of Malnutrition

Key Points

  • Malnutrition damages every organ system.
  • Terms such as Goal or Ideal Weight or range often are talking about the minimum #, and may be too low for good health for many individuals.
  • BMI does not take into account gender differences and may be too low for good health.

Central Nervous System (Brain)

  • May show signs of cognitive impairment on neuropsychological testing or in performing daily tasks.
  • Poor concentration, depressed and irritable mood.
  • Nero-imaging studies (CT, MRI) show changes in brain can occur fairly early in AN.
  • Reduction in the size of brain issue (grey and white tissue)
  • Weight restoration brings white matter volume back, however grey matter loss may persist.


  • Loss of cardiac muscle (wasting) occur early in the course of AN, with decreased heart size and thickness of walls, potentially reducing heart’s ability to pump oxygenated blood to body.
  • Generally reversible, but risk in acute stages.
  • Slow heart rate (bradycardia), >35-40bpm for adults, and > 50bpm for adolescents
  • Decreased blood pressure
  • Restricting fluids may cause orthostatic (low volume of fluid inside arteries) may cause fainting.


  • Fatigue, cold intolerance, excessive urination or involuntary vomiting may be related to changes in hormonal (endocrine) system.
  • Generally, electrolyte problems occur in those who purge by vomiting or use of diuretics or laxatives (or severely restrict fluids).
  • Having “normal labs” is not in itself indicative of good health.
  • Most of the serious complications of AN are not detected by blood tests


  • Bloating, abdominal pain, constipation
  • May result from delayed emptying time of the stomach, or slowed down digestive processes
  • Colonic transit times normalize in a few weeks with nutritional restoration.


  • Loss of menstrual periods increases the life-long risk of bone problems
  • Loss of periods from AN different than with menopause
  • Birth control pills will not protect bone health, and should not be used in AN

Renal (kidney)

  • Risk of kidney failure with severe fluid restriction (laxative or diuretic use)


  • Excessive exercise can cause stress fractures and bone pain
  • Most serious in adolescence when should be developing peak bone mass
  • Damage often permanent, starts early
  • DEXA scan in first 6 months at low weight
  • Medications used in menopausal women for osteoporosis not effective for AN
  • Weight restoration only way to stop progression of bone loss.

Skin and Hair

  • Hair loss common
  • Lanugo on body and face (fine, downy hair)

Back to Resources >

All material © 2011-2013 Rhonda Overberger. If you wish to share my original, copyrighted material, please include my name and as the source. Thank you.