Nutrition Assessment Techniques

Anthropometry

• Anthropometry is the measurement of body size, weight, and proportions
• Anthropometric measures are indicators of health, development, and growth in infants and children
• Anthropometry can evaluate nutritional status, such as obesity or emaciation from malnutrition
• Useful for monitoring effects of nutritional interventions, disease, trauma, or surgery
• Considered the method of choice for estimating body composition in clinical settings

Measuring Length, Stature, and Head Circumference

• Measurements of length, stature, and head circumference are fundamental and easily obtained anthropometric measurements
• These measurements are particularly sensitive indicators of health in infants and children

Assessing Growth and Development

• A child's growth and development can be assessed by comparing stature for age, weight for age, weight for stature, and BMI for age with standards from studies of large groups of healthy children

Calculating Indices and Estimating Expenditure

• Stature is crucial for calculating indices such as weight for stature, weight divided by stature, and the creatinine height index, used in estimating basal energy expenditure

Frankfort Horizontal Plane

• In stature measurements, positioning the head in the Frankfort horizontal plane is critical
• The Frankfort horizontal plane is a line between the lowest point on the margin of the eye socket (orbit) and the tragion (notch above the tragus, a cartilaginous projection in front of the ear lobe)
• With the head in line with the spine, this plane should be horizontal

Measuring Length

• Length (recumbent length) is used for children younger than 24 months or those who cannot stand without assistance
• Recumbent length is measured when the subject is lying down

Growth Charts

• Growth charts for ages birth to 36 months are based on recumbent length
• Growth charts for ages 2 to 20 years are based on stature

Recumbent Length Measurement Technique

• Measuring recumbent length requires a device with a stationary headboard and moveable footboard, perpendicular to the backboard
• The measuring scale should have zero at the edge of the headboard
• Two people are needed; one holds the child's head, insuring the Frankfort horizontal plane, and the other measures the length

Stature Measurement Technique

• Stature, or standing height, can be measured in subjects aged 2 to 3 years and older who can stand without assistance
• One method involves attaching a measuring stick or tape measure to a vertical surface (like a wall) and using a right-angled headboard to read the measurement

Stature Measurement Techniques (Continued)

• A wall should not have a thick baseboard and the subject should not stand on a carpet as this can affect the accuracy
• The use of a moveable rod on a platform scale is not recommended due to lack of rigidity and inconsistent headboard alignment
• A stadiometer, like the Harpeden or Seca, is a preferred method
• Barefoot and minimal clothing are required to facilitate correct positioning of the body. The subject should stand with heels together, arms to the side, and legs straight. Shoulders relaxed. Head should be in the Frankfort horizontal plane

Stature Measurement Techniques (Additional Considerations)

• Obese individuals with protruding buttocks or curvature of the spine may not be able to touch needed points on the stadiometer
• In these cases, two or three points may need to be used or height estimated from knee height
• Subjects should inhale deeply and hold their breath when measuring
• Measurements should be read to 0.1 cm or in. with eye level to the headboard to avoid parallax

Head Circumference Measurement

• Head circumference measurement is used to detect abnormalities in head and brain growth
• Crucial in the first year of life, although conditions may not be related to nutrition
• Head circumference increases rapidly in the first 12 months, then growth is much slower
• Measurement is recommended routinely in infants and young children up to 36 months

Head Circumference Measurement Technique

• Head circumference is easiest to measure when infant or child is sitting on caregiver's lap
• Older children may be measured while standing
• A flexible, non-stretchable measuring tape is required
• The tape should be in the same plane on both sides of the head, pulled snug to compress the hair
• The measurement should be read to the nearest 0.1 cm or in., written in the infant's file, reliability of the measurement verified by a second reading

Measuring Weight

• Body weight is a critical nutritional assessment measurement
• Helpful in equations predicting caloric expenditure and indices of body composition
• Weight should be taken with an electronic or balance-beam scale
• Electronic scales are often lighter, more portable, and faster, as well as easily reading digital output in metric or English units

Weight Measurement Technique (Infants)

• Infants should be weighed using a pan-type pediatric electronic or balance-beam scale accurate to 10g (0.01 kg) or .5 oz
• Cushions or diapers used are weighed and measurements then subtracted from the infant's weight

Weight Measurement Technique (Children and Adults)

• Children and adults who can stand without assistance should be weighed using a platform electronic or balance beam scale, accurate to 100g (.1kg) or 25 lb
• The weight should be read down to the nearest .1 kg or .25 lb
• Two immediate measurements need to be within 100g or .25 lb - for infants - measurements need to taken nude, or with weight of diaper subtracted

Weight Measurement Technique Considerations

• Scales should be placed on a hard flat surface; re-calibration is necessary after movement of the scale; Spring-type bathroom scales are not recommended due to possible loss of accuracy
• Ideally child or adult should be measured after voiding and dressed in an examination gown of known weight or light underclothing

Non-Ambulatory Person Weight Measurement

• Non-ambulatory people can be weighed on bed scales or chair scales
• Position comfortably in the weighing sling or sit upright in the chair, with body weight equally distributed on both feet
• Measurements should be taken using either method, the weight should be recorded to 0.1 kg or .25 lb

Skinfold Measurements

• Skinfold measurements are the most widely used method to measure and indirectly estimate percent body fat in clinical settings using the thickness of a skin fold
• Equipment is inexpensive and useful for obtaining measurements in a small space; measurements are taken quickly
• Skinfold measurements correlate well with those determined by hydrostatic weighing

Skinfold Measurement Technique

• Proper measurement of skin folds requires care in site selection and adherence to standard protocols
• Most North American researchers measure skin folds on the right side of the body. European researchers most commonly measure on the left.
• The skin fold should be correctly grasped by thumb and index finger from the correct proximal site
• The caliper should be held perpendicular to the long axis and with the dial facing up
• The caliper should not be placed too deeply into or too close to the tip of the skin fold
• The reading should be taken approximately 4 seconds after pressure is released from the caliper arm
• Two measurements should be taken at least 15 seconds apart, to allow the skin fold to return to its normal state
• Measurements, should not be taken immediately after exercising or when the subject is overheating. It takes practice

Skinfold Measurement Technique Continued

• Several types of skin fold calipers are available; the Lange skin fold caliper is among the most popular; less expensive, plastic calipers are available (eg, Slim Guide, Fat-control)
• Consistent techniques should be tested by having different technicians take measurements

This quiz covers essential techniques and practices in measuring height, head circumference, and body weight for nutritional assessments. It addresses best practices for using stadiometers and scales, ensuring accurate measurements, and the importance of head circumference in infants. Gain insight into the proper protocols for accurately assessing nutritional status.