May 2017 Issue

Eating Disorders: Preventing Side Effects in Anorexia Nervosa
By Whitney English Tabaie, MS
Today's Dietitian
Vol. 19, No. 5, P. 16

Anorexia nervosa (AN) is a severe, chronic disease with life-threatening consequences. The lifetime prevalence is 2% to 3% for women and 0.25% for men, and it's the third most common chronic condition in adolescent females.1 AN is characterized by an extreme fear of gaining weight, a distorted body image, and a persistent restriction of energy intake. While it isn't within a dietitian's scope of practice to diagnose the disease, RDs can learn to recognize the signs of illness and refer patients to outside specialists or work with an interdisciplinary health care team.

Side effects of AN are numerous, including minor, reversible complications such as brittle hair and nails to more serious, long-lasting consequences such as infertility, osteoporosis, and even death. "Because malnutrition affects every organ in the body, anorexia nervosa does too," says Jessica Setnick, MS, RDN, CEDRD, author of The Eating Disorders Clinical Pocket Guide: Quick Reference for Healthcare Providers. "Literally everything that can go wrong eventually will."

AN carries the highest mortality risk of any mental disorder.1 Heart failure and loss of brain function can result from chronic starvation or acute electrolyte imbalances, and studies show that one in five anorexia-related deaths result from suicide.1 Though recovery is challenging and can take more than a decade, dietitians can help minimize the physical, mental, and emotional damage of this devastating illness by intervening early, which "is the key to preventing permanent complications," Setnick says.

This article explores the wide range of short- and long-term side effects associated with AN and reviews the fundamental knowledge every RD needs to have to help treat this deadly disease.

Short-Term Side Effects
The immediate effects of AN-related malnutrition are apparent to even the untrained eye. In addition to appearing visibly emaciated with temporal wasting, AN patients may have dry, gray skin, brittle hair and nails, hair loss, or lanugo (soft, white hair on the face and back of shoulders).2 They also may develop carotenemia, an orange appearance to the skin caused by decelerated conversion of beta-carotene to vitamin A.2

Lab values are frequently abnormal in the AN patient, including micronutrient deficiencies such as low sodium chloride, magnesium, potassium, phosphorus, zinc, vitamin B12, and vitamin K.3 AN patients also may have a slow heart rate (bradycardia), hypotension, hypoglycemia, low thyroid hormone, and elevated liver enzymes.2 In addition, patients may experience alkalosis due to frequent vomiting.2

Other side effects include extreme fatigue, amenorrhea, bloating, constipation, gastroparesis, cold intolerance, poor immune functioning, impaired wound healing, and insomnia.1-2 "If your weight is very low, it's very hard to fall asleep, even if you've overly tired," says Robyn Goldberg, MS, RDN, CEDRD. AN patients are "constantly wired. They wake up in the middle of the night in a cold sweat because their blood glucose drops so low."

Some patients will wake up with bruises on their shins and calves, Goldberg says, "because their blood sugar drops so significantly that they are kicking themselves in their sleep. It can result in an epileptic seizure."

Long-Term Side Effects
Depending on disease severity, duration, and age of onset, some side effects of AN may become long term, despite recovery.

AN frequently overlaps with other psychiatric disorders such as depression, anxiety, posttraumatic stress disorder, substance abuse, and obsessive compulsive disorder. Studies show the lifetime prevalence of comorbidity in AN patients is approximately 40% to 45% for depression and 60% for anxiety.3

Proper nutrition may not resolve all of a patient's issues. "It isn't yet known whether anorexia nervosa causes permanent mental illness or if there's a possibility of complete remittance of anxiety or depression that's caused by the anorexia," Setnick says.

Long-term AN also can cause continued fertility issues, including severe hypoestrogenemia in women and decreased testosterone and libido in males even after recovery.4 Women with AN have higher rates of postnatal complications, postpartum depression, premature delivery, and lower birth weight babies.1

Furthermore, the disuse of the gut, and the concurrent use of compensatory mechanisms such as vomiting, laxatives, and diuretics, poses severe risks to the gastrointestinal tract. Dental caries and tooth erosion are common side effects of chronic vomiting.3 Ulcers occur in approximately 20% of patients, which can lead to bleeding and anemia.5 Gastric perforation, gastroesophageal laceration, and an increased risk of hepatic steatosis due to disturbed biosynthesis of lipoproteins are other potential, serious complications.1

Low bone density is another common side effect of long-term AN, putting patients at high risk of fractures. Studies show that approximately 92% of AN patients suffer from osteopenia and 38% from osteoporosis.6 Multiple factors may contribute to reductions in bone mass including hypoestrogenemia, hypercortisolemia, and micronutrient deficiencies.7 Because puberty is a critical time for accruing peak bone mass, women with AN onset during their teen years typically have lower bone density than those with later onset of AN.8

Finally, cardiovascular disturbances caused by malnutrition put patients at increased risk of both long-term and life-threatening problems. Decreased cardiac output causes cardiac muscle atrophy and arrhythmias such as sinus bradycardia.8 Moreover, abnormal lipid profiles are common and hypercholesterolemia may result due to reduced bile acid synthesis, which can lead to cardiovascular disease.1

RDs' Role
Dietitians play a crucial role in the recovery of AN patients, helping to restore weight and establish normal eating habits. "Eating disorders are a complex, complicated disease," says Nancy Farrell, MS, RD, FAND, a spokesperson for the Academy of Nutrition and Dietetics. "Treatment definitely requires a multidisciplinary team approach and includes a physician, RDN, psychologist/therapist, and psychiatrist."

Often, patients are resistant to treatment so it's imperative that from the beginning RDs establish trust. "I let them know that I am in the shallow end of the water with them," Goldberg says. "I'm not making them jump into the deep end alone. I work with the clients where they're at, with food choices that will feel somewhat safe and comfortable as I begin the negotiating."

AN patients' energy requirements are drastically increased. This may be partially explained by increased diet-induced thermogenesis, which can be up to 30% of resting energy expenditure in AN patients compared with 14% to 16% in healthy adults.9 Research shows that hypermetabolic patients may need up to 70 to 100 kcal/kg/day to achieve weight restoration.9 Normalization of metabolism occurs three to six months after patients return to a healthy weight.9 However, calories and other food measurements aren't routinely discussed with AN patients because this information may trigger obsessive thoughts or behaviors.2 Focusing on qualitative dietary information vs quantitative is an effective tool for helping patients regain normal eating patterns.

RDs assist in reaching caloric needs through collaborative meal planning with patients. Patients are encouraged to eat small, frequent meals, select fiber-rich, nutrient-dense foods, and limit caffeine, which can suppress appetite.10 A balanced, varied diet is recommended, with a high emphasis on essential fatty acids, as AN patients tend to avoid consuming fat.9 Initially, patients may need to limit lactose-containing foods, since intolerance can develop from gastrointestinal disuse.10 If a patient has micronutrient deficiencies, a multivitamin or supplement is advised.10

Dietitians also can provide nutrition counseling using intuitive eating concepts to help normalize eating patterns. Exercise is typically discouraged in the early stages of treatment, but may be incorporated once a patient is weight stable. Later in treatment, some RDs incorporate experiential eating exercises and outings to help clients become comfortable with food-related activities such as dining out, cooking, or grocery shopping.

Monitoring and Evaluation
Weight gain in the outpatient setting usually is set at a goal rate of 0.5 to 1 lb/week.3 In females, weight restoration should result in the return of menses. RDs may take their patients "blind weight" weekly to help monitor progress. Blind weighing is when the medical professional sees the value but the patient doesn't. Some RDs will cover the display on the scale or have the patient face backward so they're unable to see the number. However, weight isn't the only parameter for success.

Goldberg says recovery is about learning to quiet the internal voice. "Recovery is no longer thinking about, 'will this food make me fat,' or having constant feelings of guilt or shame about a specific food," Goldberg says. "It's thinking: food is fuel. It sustains me, and provides me pleasure. I can now focus on all the things in my life that I enjoy doing that I'd forgotten about."

Despite previous reports of low recovery rates for AN, new research shows that approximately 30% to 50% of patients achieve full recovery within 10 years, and approximately 75% within 20 years.11 These statistics offer a more optimistic outlook than often is presented, and emphasize the need for experienced dietitians who specialize in treating this challenging disease.

— Whitney English Tabaie, MS, graduated from the University of Southern California's School of Gerontology with a Master's Degree in Nutrition, Healthspan, and Longevity and plans to take the Commission on Dietetic Registration exam this summer. She shares her nutrition knowledge and love of plant-based cooking on her blog To Live & Diet in LA.

1. Meczekalski B, Podfigurna-Stopa A, Katulski K. Long-term consequences of anorexia nervosa. Maturitas. 2013;75(3):215-220.

2. Practice paper of the American Dietetic Association: nutrition intervention in the treatment of eating disorders. Academy of Nutrition and Dietetics website.
. Accessed March 28, 2017.

3. Halmi KA. Classification, diagnosis and comorbidities of eating disorders: a review. In: Maj M, Halmi K, Lopez-Ibor JJ, Sartorius N, eds. Eating Disorders. Vol 6. England: John Wiley and Sons Ltd; 2003:1-33.

4. Meczekalski B, Podfigurna-Stopa A, Genazzani A. Hypoestrogenism in young women and its influence on bone mass density. Gynecol Endocrinol. 2010;26(9):652-657.

5. Hall RC, Beresford TP. Medical complications of anorexia and bulimia. Psychiatr Med. 1989;7(4):165-192.

6. Mitchell J, Crow S. Medical complications of anorexia nervosa and bulimia nervosa. Curr Opin Psychiatry. 2006;19(4):438-443.

7. Misra M. Long-term skeletal effects of eating disorders with onset in adolescence. Ann N Y Acad Sci. 2008;1135:212-218.

8. Casiero D, Frishman W. Cardiovascular complications of eating disorders. Cardiol Rev. 2006;14(5):227-231.

9. Marzola E, Nasser JA, Hashim SA, Shih PA, Kaye WH. Nutritional rehabilitation in anorexia nervosa: review of the literature and implications for treatment. BMC Psychiatry. 2013;13:290-303.

10. American Dietetic Association. Nutrition Care Manual. Anorexia nervosa: nutrition prescription. Accessed March 28, 2017.

11. Eddy KT, Tabri N, Thomas JJ, et al. Recovery from anorexia nervosa and bulimia nervosa at 22-year follow-up. J Clin Psychiatry. 2017;78(2):184-189.