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Part II Nutrition Assessment, Consequences, and Implications

preparation is often a challenge in free-living older adults who may rely on easy-to-prepare and processed foods. For those who require enteral or parenteral feed- ings for nutrition support, macro- and micronutrients will be supplied by the enteral formula or IV solution. Energy needs of adults decrease with age because of a decreased basal metabolic rate associated with dimin- ished LBM. Energy needs vary by age, activity, disease state, and gender and therefore need to be individual- ized. The Mifflin-St Jeor equation, which considers height, weight, age, and gender to predict energy needs at rest, may be used for older adults (10). It is important to consider the level of activity and the disease state when determining energy requirements. Level of activ- ity may be extremely low and very close to the resting metabolic rate (RMR). Therefore, an additional 10% to the RMR and up to 20% to 30% may be used to account for activities of daily living based on the individual’s abilities and living environment. When determining energy needs of older adults, it is also important to con- sider the disease state or whether acute or chronic illness is present. As with any person receiving nutrition support, energy levels should be adjusted as needed to meet the established goal weight.

Protein

The recommendation for protein intake in adults 51 to 70 years and for those older than 70 years is 0.8 g/kg body weight. Acute illness or conditions of metabolic stress or infection warrant increased provision of protein. Critically ill older adults require 1.7 to 2.2 g of protein per kg of body weight to reach nitrogen balance (12). Older adults who are bedridden or immobile need increased protein because of the negative nitrogen balance associated with inactivity. Inadequate provision of protein may contribute to loss of LBM. Conditions that require decreased protein intake include hepatic failure or age-related diminished renal function. Paddon- Jones has recommended 30 g of protein three times per day (ie, breakfast, lunch, and dinner) for the older adult to maintain protein synthesis and therefore maintain muscle health and status (11). This may have to be achieved using a protein supplement or higher protein nutrition support regimen.

Carbohydrate

Intake from carbohydrate is typically 45% to 65% of total energy needs. Aging adversely affects carbohy- drate metabolism, and older adults are more likely to experience hyperglycemia than younger adults (8). Enteral and parenteral formulas with high carbohydrate content may not be well tolerated. However, special- ized lower carbohydrate enteral formulas should be

considered only after a trial and failure on a standard enteral formula.

Fat

Fat provides a source of energy and essential fatty acids and is necessary for absorption of fat-soluble vitamins. Fat makes up the balance of calories after carbohydrate and protein, at approximately 20% to 30% of total energy calories. Standard 1 kcal/mL enteral products provide approximately 30% of the energy as fat. Clients receiving parenteral nutrition should receive at least 10% (and usually no more than 1 g/kg of body weight) of their energy calories from intravenous fat emulsion to meet their essential fatty acid requirement (13).

Vitamins and Minerals

The intake of vitamins and minerals in older adults parallels their decreased energy intake. Because of age-related decreased absorption in the GI tract, defi- ciencies may develop, especially during an acute illness secondary to decreased body stores. Dietary Reference Intakes (DRIs) include the age categories of 51 to 70 years and over 70. Enteral formulas contain vitamins and minerals that provide 100% or more of the Reference Daily Intake based on the amount of formula administered, although these are not specific for the older adult population. Multivitamin and mineral preparations are added to parenteral nutrition formulas daily. Certain vitamins such as B-12, D, and others may be further affected by actual intake and disease, so it is important to review vitamin intake in the older adult and evaluate for the potential for defi- ciencies with the concomitant effects of disease for those receiving oral, enteral, or parenteral nutrition (8).

Fluid

Older adults have fewer compensatory mechanisms than younger adults for restoring and maintaining homeostatic norms due to age-related declines in renal and cardiac function. These then negatively affect the ability to maintain adequate hydration. Dehydration is the most common fluid and electrolyte disturbance in older clients. Fluid recommendations include 1 mL fluid/kcal or 30 mL/kg of body weight (8). Thirst detection, urination, and food intake may be altered in older adults, and they should be closely monitored for adequate fluid balance.

Ethical Considerations

The indications for nutrition support in older adults are based on the same medical indications and principles used for younger adults. However, ethical considerations are more likely to play a factor in the decision to initiate