Health and Nutrition Assessment Handbook (HNAH)

Revised December 2025

Local agencies (LA) are responsible for the purchase, maintenance, repair costs and replacement of anthropometric equipment as allowed by their contract. LAs may contact their district's technical assistance (TA) nutritionist or other agencies for recommendations on equipment. Before buying any equipment, determine if companies in the area provide service or repairs, if needed. LAs are required to have anthropometric equipment purchases approved by their district nutrition TA. Refer to the WIC Operations Manual (WOM) policy 5.1.070 Line Item: Equipment Purchases.

When contacting a company to place an order, confirm the company’s return policy and whether the company guarantees the equipment against defects for at least one year. Determine who should be contacted regarding returns or repairs, if applicable. Inquire about price, volume discounts and the cost of replacement parts. Pediatric examination tables are allowable when the minimum criteria for weight and length equipment are met.

LAs must keep the equipment manuals on file after purchase. These manuals serve as a valuable resource for understanding the equipment's specifications, operating procedures and maintenance requirements, thereby promoting efficient equipment management.

Minimum criteria for measuring equipment

Minimum criteria for a recumbent length board (mechanical and digital)

• Must be constructed of durable (non-flexible), easy-to-clean materials with no sharp edges or unfinished parts.
• Must be a firm, inflexible, flat, horizontal surface. Cushioning is acceptable if it is part of the manufacturer's device.
• A measuring tape must be made of a non-stretchable material (embedded if possible) and clearly marked to one-eighth inch or one mm or less.
• Digital infantometers must have gradations to one-eighth inch.
• A fixed head piece must extend above the measurement surface, at a right angle (90 degrees). The zero-inch mark must be exactly at the base of the headboard.
• Must have a smooth, movable, mounted footboard perpendicular to the tape.
• A pediatric examination table foot piece must be stable and locked when perpendicular.

Minimum criteria for a stadiometer (mechanical and digital)

• Must have a vertical ruler clearly marked in increments of one-eighth inch or one mm or less. The entire ruler must be securely attached to a solid surface, mounted on a board or attached to a flush wall without floor molding.
• Should allow, at a minimum, the heels, buttocks, shoulder blades and the back of the head to be in contact with the vertical surface of the equipment when measuring.
• If the equipment does not extend to the floor, an extension must be attached to complete the vertical surface.
• If mounted, the equipment should have a removable or attached headboard at a right angle (90 degrees) to the measurement surface.
• A digital stadiometer must have a hold function.
• The measuring arm on the platform scale is not an approved device for measuring the height of children or adults.

Minimum criteria for weighing equipment

Minimum criteria for scales (mechanical and digital)

• Must be constructed of durable, easy-to-clean materials with no sharp edges.
• Must be placed on a hard floor or a hard surface if the floor is carpeted.
• Spring-type bathroom scales are not acceptable.

Mechanical scale guidelines

• Must have a mechanism to allow a zero balance. An adjustable screw type is preferred.
• Must have a mechanism to allow calibration.

Infant scales

• Must be marked in increments of one ounce or less and accurate to that degree.
• Must have a capacity of at least 40 pounds.
• Must have a sturdy infant cradle.

Adult/child scale

• Must have a platform.
• Must be marked in increments of four ounces or less and accurate to that degree.
• Must have a capacity of at least 500 pounds.
  • Prior to federal fiscal year (FFY) 2026, the capacity requirement was 300 pounds. Scales purchased prior to FFY 26 that meet the previous capacity are grandfathered in and do not need to be replaced if still in working condition.

Digital scale guidelines

• Must have an automatic zero.
• Must have an automatic tare to zero.
  • Some digital scales come with a tare feature that allows the scale to be reset to zero while the caregiver is standing on it, before handing the infant to them. Once you have tared the scale to account for the caregiver’s weight, only the weight of the infant will be displayed.
• Should have a feature where the weight can be locked in.
• Must provide measurement reproducibility (i.e., consistent readings).
• Choose a scale based on its intended location, such as satellite clinics or LA, and consider whether the power source will be electrical, battery or both.
• Must provide accurate measurements, with minimum error at both low and high ends of the scale range.

Infant digital scale

• Must have a sturdy cradle to support the infant.
• Must have a minimum weighing capacity of 40 pounds.
• Must have a large enough cradle to ensure the infant’s safety.
• Must have accuracy within one ounce.

Adult and child digital scale

• Must have an accuracy within one-quarter pound or 100 grams.
• Must have a capacity of at least 500 pounds.
  • Prior to federal fiscal year (FFY) 2026, the capacity requirement was 300 pounds. Scales purchased prior to FFY 26 that meet the previous capacity are grandfathered in and do not need to be replaced if still in working condition.

Equipment inspections

Scales must be inspected for accuracy before using new equipment, whenever equipment is moved and annually. If calibration is required, refer to the equipment manual for instructions.

Stadiometers and recumbent length boards must be inspected to ensure accuracy before use for new equipment, when equipment is moved and annually. If the stadiometer or recumbent length board requires calibration, refer to the equipment manual for calibration instructions.

Training

Qualified LA staff must complete anthropometric training before performing measurements in the clinic. They will finish the Anthropometric Assessment training and the Anthropometric Comprehension quiz, which are available on the eLearning page of the LA Portal.

Document all training on the WIC Staff Training Record and keep certificates of completion.

Procedures for weighing

All participants should be weighed at every certification and mid-certification, unless appropriate referral data was provided before the appointment, and the data collected is recorded in the Management Information System (MIS). They may be weighed more frequently as determined by WIC Professional staff.

Infants and children 12-23 months must be weighed on an infant scale.

Children 24-59 months and women are weighed on an adult and child scale while standing upright.

All scales should be cleaned daily and as needed. If no scale paper is used, clean after each participant.

Refer to the manufacturer’s equipment specifications for additional operating instructions.

Measuring weight for an infant or child under 2 years of age

1. Instruct the parent or guardian to undress the infant down to a dry diaper. Children must remove their shoes and any heavy outer clothing. They must have a dry diaper or pull-up.
2. Check scales for zero balance.
   1. For mechanical scales, first balance the scale. The scale is balanced when the marker indicates zero with the weights in the zero position, or when the marker is positioned in the middle of the cut-out area on the balance beam. When necessary, move the weights to zero and turn the adjustment screw until the scale is balanced.
   2. For digital scales, turn the scale on and ensure it is zeroed before weighing the participant.
3. Measure weight based on the type of scale.
   1. For mechanical scales:
      1. Place the infant or child in the center of the scale, either lying down or sitting up. The infant or child cannot be holding on to the scale or have anything in their hands.
      2. Move the beam’s lower weight away from zero until the marker drops below the center point. Then slide the lower weight back one notch toward zero until the marker is above the center point.
      3. Slide the beam’s upper weight away from zero until the marker is centered. Moving the upper weight back and forth a few times until the scale is balanced may be necessary.
      4. The participant’s weight is displayed when the marker is balanced in the center of the cut-out portion, not touching the top or bottom.
   2. For digital scales:
      1. Place the infant or child in the center of the scale, either lying down or sitting up. The infant or child cannot be holding on to the scale or have anything in their hands.
      2. Ensure the participant remains on the scale until the reading is stable, the machine beeps or the display indicates the weight is locked in.
4. Read the weight to the nearest ounce and record the information in the MIS.
5. If the scale displays as a decimal weight instead of ounces, use the chart below to convert the decimal weight to ounces.

Infant test weighing

Test weighing is a method where an infant is weighed before and after breastfeeding to determine the amount of milk intake during that feeding.

An international board certified lactation consultant (IBCLC) must conduct or supervise test weighing in the LA.

The purpose of the test weight is to determine how effectively milk is transferred during feeding and to provide reassurance to mothers that their infant is transferring milk.

Breastfeeding infants ingest different amounts of milk at each feeding, so test weighing during one feeding does not offer a valid representation of an average feeding or allow calculation of overall intake. Studies have shown that infants must be weighed before and after every feeding for three days to establish an average feeding amount. Test weighing may be used in complicated clinical situations to monitor intake and adjust the volume of supplementation, such as in the neonatal intensive care unit (NICU).

Test weighing may be used in the LA as one measure of intake, in addition to other measures such as diaper output, weight gain or loss and mother’s report of feeding frequency and efficacy.

Principles to consider:

• A digital scale must be accurate to two grams or less and have an integration function allowing the infant’s movement.
• Infants are weighed before and after feeding, either without clothes or with the exact same clothing. The diaper should not be changed between the first weight and the second weight.
• The difference in grams between the first and second weights is considered the intake in milliliters. Some scales automatically store weights and compute the difference in milliliters; check the manufacturer’s instructions.

Measuring weight for a woman or child 2-5 years of age

1. Instruct the parent, guardian or participant to remove any extra clothing, such as a jacket, sweater or sweatshirt, empty their pockets of heavy items, and remove their shoes. Ask the parent or guardian to ensure the child has a clean, dry diaper or pull-up.
2. Check scales for zero balance.
   1. For mechanical scales, first balance the scale. The scale is balanced when the marker indicates zero with the weights in the zero position, or when the marker is in the middle of the cut-out area on the balance beam scale. When necessary, move the weights to zero and turn the adjustment screw until the scale is balanced.
   2. For digital scales, turn the scale on and ensure it is zeroed before weighing the participant.
3. Instruct the participant to stand in the center of the scale’s platform, look straight forward, feet slightly apart and with arms hanging naturally at their side.
4. Obtain measurement.
   1. For mechanical scales:
      1. Move the beam’s lower weight away from zero until the marker drops below the center point, then slide the lower weight back one notch toward zero until the marker is above the center point.
      2. Slide the beam’s upper weight away from zero until the marker is centered. The upper weight may need to be moved back and forth a few times until the scale is balanced.
      3. The participant’s weight is displayed when the marker is balanced in the center of the cut-out portion, not touching the top or bottom.
   2. For digital scales:
      1. Ensure the participant remains on the scale until the reading is stable, the machine beeps or the display indicates the weight is locked in.
5. Read the weight measurement in pounds and ounces, and record the information in the MIS.
6. If the scale displays as a decimal weight instead of ounces, use the decimal-to-ounces conversion chart above to convert the decimal weight to ounces.

If the participant’s weight exceeds the LA’s scale's measurement capacity, the LA will record the maximum value the scale can measure in the Weight field within the Length/Height/Weight tab of the MIS. The LA will select “Greater than (>) Scale Max” as the Incorrect Measurement Reason.

Procedures for height or length measurements

All participants should have a height or length measurement at every certification and mid-certification, unless appropriate referral data was provided prior to the appointment, and the data collected is recorded in the MIS.

All infants and children under 24 months should be measured while lying on a recumbent length board. Accurate measurement for children under 24 months requires the assistance of two people.

Height (stature) is the measurement of the distance from the top of the head to the bottom of the feet, which is performed standing upright.

Length (recumbent) is the measurement of the distance from the top of the head to the bottom of the feet that is performed lying down.

Height and length are not the same and cannot be used interchangeably.

Measuring length for an infant or child under 2 years of age

1. Place scale paper on the measuring board, if applicable.
2. Lay the infant or child face up on the length board. The body must be straight and lined up with the board.
3. Have the parent or guardian hold the infant or child’s head firmly against the non-moveable headboard until the measuring is completed.
4. Using one hand, hold the infant or child’s legs together just above the knees and gently push both legs down to fully extend their legs. Avoid using just one leg to measure, as this technique can displace the hip and make the infant or child appear longer than their actual length.
5. With the other hand, move the footboard until it rests firmly against the infant or child’s heels. The toes must be pointed directly up.
6. Read the measurement to the nearest eighth inch and record the information in the MIS.
   1. For digital infantometers that measure to the nearest hundredth, use the hundredths conversion table below to convert the decimal reading to the nearest eighth inch.
   2. For digital infantometers that measure to the nearest tenth, use the tenths conversion table below to convert the decimal reading to the nearest eighth inch.
7. The measuring board must be cleaned daily and as needed. If no scale paper is used, it should be cleaned after each participant.

Conversion tables for step 6:

Measuring height for a woman or child over 2 years of age

1. Have the participant remove their shoes and hat. Move any hairstyle or hair accessory out of the way that would obstruct or affect the accuracy of the measurement.
2. Have the participant stand on the bare flat surface, with heels slightly apart and feet flat on the floor.
3. Have the participant stand with their back as straight as possible and no bend in the knees. Heels, buttocks, shoulder blades and the back of the head should touch the wall or measuring surface.
   1. Depending on a person's overall body shape, not all four contact points may touch the measuring surface.
   2. Some narrow stadiometers may not allow contact with all points. In such cases, have as many contact points as possible.
4. Have their arms hanging naturally to the side, shoulders relaxed.
5. Ensure they are looking forward, with eyes straight ahead.
6. Slowly lower the movable headboard until it touches the crown of the head firmly.
7. Read the measurement to the nearest eighth inch and record information in the MIS. The measurer’s eyes should be parallel with the headpiece to ensure an accurate reading.
8. For digital stadiometers that measure to the nearest tenth or hundredth, use the conversion tables above to convert the decimal reading to the nearest eighth inch.

Nonstandard procedures

Contractures at the hips, knees and ankles can interfere with the accuracy of anthropometric measurements. Several measures are useful alternatives to length or height.

If a participant has a physical disability that prevents them from being measured using standard procedures, document it in the MIS by selecting “Participant Disability” in the Length/Height/Weight tab. Document further information in the SOAP note and by assigning any appropriate risk factor(s). Nonstandard procedures may be used, or referral data may be obtained from the health care provider.

Nonstandard procedures will not correlate directly with height or length, but can indicate a child’s rate of growth as plotted on the growth grids. Although the measurements may be in a low percentile for age, they will show whether the child is following a consistent growth curve.

Participant unable to stand or an uncooperative child

Crown-rump length

Children who are unable to stand without support should be measured by crown-rump length measurement. To take crown-rump length measurements, use the same technique as measuring length, except bend the child’s legs at a 90-degree angle and bring the footboard against the buttocks. Document in a general or SOAP note in the MIS that a crown-rump length measurement was taken. 

Weight

Children unable to stand on the scale may be weighed using an alternative method. Have the caregiver stand on the scale, tare the scale to zero, then have the caregiver hold the child. The child's weight will be displayed on the scale.

This procedure may be used for uncooperative children who refuse to be weighed using standard procedures. Ask the parent or caretaker to take the child out of the room and try to calm the child, then attempt to weigh the child again. Document the weight in the MIS, select “Uncooperative Client” in the Length/Height/Weight tab and provide further explanation in the general or SOAP note.

Referral data from the health care provider within the last 60 days can be used for an uncooperative child.

Participants wearing a cast

An individual wearing a cast can usually be weighed using standard procedures. The presence of a cast should be documented in the general or SOAP note. In this situation, overweight risk factors may not be used for WIC certification and plotting on the growth charts will be affected.

If the participant is wearing a cast that prevents the standing height measurement from being obtained, include documentation in the general or SOAP note. Omit the height measurement until the cast is removed and the height can be measured accurately. If an individual is wearing a cast that does not prevent their height from being obtained, complete the measurement using standard procedures and document that a cast was worn in the note.

One leg is shorter than the other

If a child is less than 3 years of age and one leg is shorter than the other, the child should be measured lying down. Both legs should be fully extended. A child over 3 years of age or a woman can be measured in a standing position by having them stand on their longest leg. Document how the measurement was obtained in the MIS.

Amputee and missing limbs

Infants or children missing arms or legs may be weighed using the standard procedure on the mechanical or digital scale. Document the weight and the physical condition in the MIS. Risk factors for being underweight cannot be used for WIC certification in this situation.

For older children or adults who cannot stand to be weighed and cannot be weighed by a parent or caretaker, document the weight as “Unknown” and select “Participant Disability” in Incorrect Measurement Reason in the MIS. If the participant grants permission, the LA may contact the participant’s health care provider to obtain referral data.

Participants with missing limbs that do not prevent the measurement of recumbent length or height should have the measurement taken using the standard procedure.

If the participant is missing limbs that prevent the measurement of recumbent length or height, the LA staff should document this as “Unknown” and select “Participant Disability” under the Incorrect Measurement Reason in the MIS. If the participant grants permission, the LA may contact the participant’s health care provider to obtain referral data.

It is important to note that the growth percentile for weight for height or length will not be accurate because of missing limbs. However, plotting the participant’s weight gain over time will still help assess growth.

Above or below MIS limits

If a participant’s length, height or weight is above or below the minimum or maximum allowed for their category in the Length/Height/Weight tab of the MIS, LA staff will be unable to enter the value.

If the participant is below the minimum, enter the minimum for their category, select “Participant Disability” from the Incorrect Measurement Reason and document the correct value in the note.

If the participant is above the maximum, enter the maximum for their category, select “Participant Disability” from the Incorrect Measurement Reason and document the correct value in the note.

It is important to note that if the minimum or maximum from the system is entered, it will not be an indicator of overall growth.

Body mass index (BMI)

Body mass index (BMI) is an anthropometric index of weight and height. It is the commonly accepted index for classifying adiposity in adults and has become the recommended index for children and adolescents.

In adults, BMI is expressed as a specific value calculated from weight and height.

In children and adolescents, BMI is age and gender specific and is identified by percentiles on the growth chart after incorporating the person’s age as a factor.

BMI is a screening tool used to identify individuals who are underweight, overweight and normal weight. BMI is not a diagnostic tool.

BMI will be automatically calculated in the MIS.

Standards for children

BMI is calculated for children 2 years of age and older after their height and weight are measured. It is plotted on the BMI growth grid.

It is recommended that terms such as “overweight” and “obese” be used only for risk assessment, while more neutral terms, such as “excess weight relative to height,” “excess weight,” or “excess BMI,” should be used when discussing a child’s weight with a parent or caregiver.

Standards for prenatal weight

Pre-pregnancy BMI is used to determine recommended pregnancy weight gain. LA staff should obtain her current height. If the pre-pregnancy weight is not known, use the woman's self-reported pre-pregnancy weight or her first-trimester weight, as per CDC guidelines. The pre-pregnancy BMI will appear in the Health Information tab of the MIS.