Nutrition and You
“Balance”—we hear the term all the time. In the case of nutrition, it means “a state of equilibrium.” That is, if you “balance” what you take in nutritionally with what you put out in energy and activity, you will be “in balance.” It is not unusual for home parenteral and enteral nutrition (HPEN) consumers to watch intake and output (I and O) to reflect fluid balance, but it is also important to monitor I and O for nutritional balance.
Weight loss or weight gain can result from too little or too much fluid intake from oral, enteral, and/or parenteral sources. However, it is important to remember that weight balance can also depend on calorie balance. Weight loss or gain due to changes in calorie I and O may be more gradual than weight changes due to fluids.
So how many calories do you need each day? There are a lot of ways to figure this out. There are Recommended Daily Allowances (RDAs). These group males and females in different categories and determine calories needed by age. There are also some general guidelines based on calories per kilogram. But to most accurately know how many calories you need, you need to know what your basal or resting metabolic rate (RMR) is and the average amount of activity you do each day. Combining those two factors will approximate your daily “energy expenditure” or calorie needs (calories [kcals]/day = RMR calories + calories for activity).
When you started on HPEN, your clinicians would have calculated your overall calorie and nutrient needs to provide the enteral or parenteral formula that would help you maintain optimal health. These numbers should be recalculated if your medical condition, weight, or activity level change significantly.
RMR is often estimated using equations. This estimated RMR varies among individuals, and according to the equation used. The activity factor, added to the RMR to determine daily calorie needs, is also estimated; your clinician may adjust the factor to better reflect your activity level. RMR in adults is often estimated using the Mifflin St. Jeor Equation. Let’s use this equation to estimate the RMR for a 45-year-old woman who weighs 130 lbs (59 kg) and is 5’ 4” (162.5 cm) tall. Then we’ll add an additional amount of calories to the RMR to account for activity (we will estimate she needs another 30% of her RMR for minimal activity).
Equation (note that equation is adjusted for gender):
Male: RMR (kcal/day) = [10 x (wt
in kg)] + [6.25 x (ht in cm)] – [5 x (age in yrs)] + 5
Female: RMR (kcal/day) = [10 x (wt in kg)] + [6.25 x (ht in cm)] – [5 x (age in yrs)] - 161
• Convert pounds (lbs) to kilograms (kg) by dividing lbs by 2.2 (130/2.2 = 59)
• Convert inches to centimeters (cm) by multiplying inches by 2.54 (64 x 2.54 = 162.5)
RMR = (10 x 59) + (6.25 x 162. 5) – (5 x 45) – 161 = 1220 kcal/day
Calories for activity: 1220 x 30% = 366
Daily calorie needs for this 45-year-old, minimally active woman: 1220 + 366 = 1586 kcal/day
Your Balance, Your Weight
The “balance” comes in as you monitor your body weight.
• Are you gaining weight? If so, why? Could it be due to less exercise or activity (because you’ve been feeling bad, it’s too cold to go outside, or you’ve suffered an injury, for example)? Are you absorbing more oral calories?
• Are you losing weight? If so, why? Could it be due to more exercise or activity because you have been feeling better? Are you no longer able to eat orally? Could you be malabsorbing nutrients? Are you infusing your entire amount of feeding, whether EN or PN?
Whether you are a consumer of EN or PN or eat a regular diet, you have to balance the calories you take in with what you expend in activity and exercise. How is your balance? Need help? Contact your registered dietitian or send us a question!
This column has been compiled and reviewed Carol Ireton-Jones, PhD, RD; Laura Matarese, PhD, RD, LD, FADA, CNSD; Cheryl Thompson, PhD, RD, CNSD; and. Marion Winkler, PhD, RD, CNSC.
The LifelineLetter, September/October 2010