Chapter 30: Nutrition Disorders, Obesity, and Enteral/Parenteral Alimentation

Learning Objectives

• Describe the important interrelationship between diet and physical activity in maintaining or restoring lean body mass (LBM) and the resulting effects this interaction has on total body mass in older adults.

• Describe the changes in body composition that occur over the adult life span and what physiologic, dietary, lifestyle, and disease factors are responsible for these changes.

• Describe the changing prevalence of obesity among older adults and be able to assess the impact of excess weight on the health status of older patients.

• Advise older adults about what constitutes an optimal diet and the advisability of using nutrient supplements given their health status.

• Describe common factors contributing to undernutrition in older adults.

• Identify the three most common causes of weight loss in older adults.

• Determine appropriate nutritional support interventions for persons with protein-energy malnutrition (PEM).

Key Clinical Points

1. With advancing age, the ratio of fat to total body mass increases regardless of whether total body weight increases or remains constant.

2. Although skeletal muscle mass generally declines with advancing age, the rate of decline in healthy individuals is highly dependent on the individual’s habitual level of physical activity and the quality of his/her diet.

3. Although the impact of excess weight (ie, body mass index [BMI] > 25 kg/m²) on long-term survival is highly controversial, there is a strong direct relationship between the level of obesity and the risk of developing disabling chronic diseases such as severe osteoarthritis, type 2 diabetes, and heart disease.

4. There is no evidence of benefit for any micronutrient supplement in healthy older adults who do not have a documented deficiency of the given nutrient or a condition that places them at high risk for the development of such a deficiency. Supplements of vitamins and minerals do not prevent or treat cardiovascular disease (CVD), cancer, or dementia.

5. Vitamin and mineral supplements, above the recommended upper limit (UL), increase adverse health outcomes. The National Academy of Medicine provides evidence-based guidelines for Recommended Dietary Allowances of vitamins and minerals for most individuals.

6. Laboratory blood tests of serum proteins (such as albumin and prealbumin) are indicators of inflammatory status, disease severity, and morbidity risk, rather than nutritional status.

7. Weight loss of 5% or more of baseline body weight over 6 to 12 months is associated with increased morbidity and mortality and should prompt clinical investigation.

8. When malignancy is the cause of weight loss, the diagnosis is usually readily made with standard evaluations that include a careful history, physical examination, and basic laboratory tests.

9. High-protein, high-calorie oral nutritional supplements may reduce morbidity and mortality when provided to hospitalized malnourished patients age 75 or older.

10. Enteral nutrition (EN) is preferred over parenteral nutrition (PN) for patients who are in need of nutritional support and have a functional gastrointestinal (GI) tract.