Elsevier

Mayo Clinic Proceedings

Volume 76, Issue 9, September 2001, Pages 923-929
Mayo Clinic Proceedings

Review
Rational Approach to Patients With Unintentional Weight Loss

https://doi.org/10.4065/76.9.923Get rights and content

Unintentional weight loss is a problem encountered frequently in clinical practice. Weight loss and low body weight have potentially serious clinical implications. Although a nonspecific observation, weight loss is often of concern to both patients and physicians. There are multiple potential etiologies and special factors to consider in selected groups, such as older adults. A rational approach to these patients is based on an understanding of the relevant biologic, psychological, and social factors identified during a thorough history and physical examination. The goal of this article is to discuss the clinical importance, review potential pathophysiology, and discuss specific etiologies of unintentional weight loss that will enable the clinician to formulate a practical stepwise approach to patient evaluation and management.

Section snippets

PATHOPHYSIOLOGY OF WEIGHT LOSS

The precise mechanism of weight loss is unknown in many patients. Caloric intake, absorption, utilization, and loss are key components that determine an individual's weight. Alteration in the balance of these components affects a patient's ability to maintain weight. For example, caloric intake may be modified by altered smell or taste, anorexia, nausea, abnormal satiation, etc. Absorption may be modified by altered gastrointestinal motility, exocrine pancreatic function, mucosal absorptive

ETIOLOGIES OF WEIGHT LOSS

Whereas dieting and eating disorders (ie, anorexia nervosa and bulimia nervosa) explain most cases of intentional weight loss, unintentional weight loss can be divided into organic, psychosocial, and idiopathic etiologies. Additionally, selected groups (eg, older adults) often have multiple etiologies to explain their weight loss. Three studies that have evaluated the etiologies of unintentional weight loss, defined as more than 5% of usual body weight, are summarized in Table 1.17, 18, 19

EVALUATION OF UNINTENTIONAL WEIGHT LOSS

In most patients, the etiology of unintentional weight loss is identified through a detailed history and physical examination. Key concepts of the evaluation include: (1) document weight loss-in up to 50% of patients, weight loss cannot be documented13; (2) perform a detailed history-medical, psychosocial, and dietary-and physical examination; (3) perform tests based on history and physical findings in conjunction with limited standard tests; and (4) establish appropriate follow-up to assess

MANAGEMENT PRINCIPLES

Early intervention based on the findings of the diagnostic evaluation provides the greatest opportunity for success. The severity of weight loss should be determined by a nutritional assessment, including a biochemical analysis combined with a thorough dietary history, evaluation of the patient's psychosocial situation, and consideration of anthropometric or other qualitative evaluations. A simple and common anthropometric evaluation is the body mass index (BMI). The BMI is defined as body

SUMMARY

Body weight, as determined by several key components, remains relatively stable over time. Unintentional weight loss, defined as a decrease of more than 5% of usual body weight during a 6- to 12-month period, is an important predictor of morbidity and mortality. However, weight loss is a nonspecific finding with multiple possible etiologies, including organic, psychosocial, and idiopathic. A rational stepwise approach based on relevant data extracted from the history and physical examination,

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    This work was presented in part at the Tenth Annual Advances and Controversies in Clinical Nutrition Course sponsored by Mayo Foundation and the American Society for Parenteral and Enteral Nutrition on April 28, 2000, in Tempe, Ariz.

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