Anthropometry in Adults

Introduction

• Course: AGN 3311 - Nutrition Assessment

• Focus Topic: Anthropometry in Adults

Nutrition Indicators

• Definition: Nutrition indicators are interpretations of nutrition indices based on cutoff points.

• Purpose:

  • Measure clinical phenomena of malnutrition.

  • Assist in making judgments or assessments regarding nutrition status.

• Characteristics of a Good Nutrition Indicator:

  • High sensitivity: detects as many at-risk individuals as possible.

  • High specificity: minimizes false positives (people not at risk).

  • Functionally meaningful: related to morbidity and mortality risk, sensitive to changes in status.

• Standard Cutoff Points Defined:

  • Under-nutrition

  • Optimal nutrition

  • Overnutrition

Adult Anthropometry [1]

Measurements

• Weight and height (in kg and meters).

• Waist and hip circumferences (in cm).

Indices

• Body Mass Index (BMI) in kg/m².

• Waist-to-hip ratio.

• Additional indices (consider age):

  • Mid-upper-arm circumference (MUAC).

  • Skin fold thickness (indicates subcutaneous and total body fat).

  • Waist circumference (for body fat distribution).

Taking Measurements for Adults

Height

• Procedure:

  • Subject stands erect and bare-footed on a stadiometer.

  • Use a movable headpiece, leveled with the skull vault.

  • Record height to the nearest 0.5 cm.

Weight Measurement

• Equipment: Regularly calibrated electronic or balanced-beam scale.

• Procedure:

  • Weigh in light clothing and no shoes.

  • Read to the nearest 100 grams (0.1 kg).

Body Mass Index (BMI)

Calculation

• Formula: BMI = \frac{\text{weight (kg)}}{\text{(height (m))^2}}

• Purpose:

  • Screening tool for weight problems that may lead to health issues.

  • Reliability in indicating body fatness and estimating critical fat values linked to increased disease risk.

  • Acceptable standard for assessing overweight and obesity.

Reliability of BMI

• BMI is generally reliable for most but exceptions exist:

  • Bodybuilders & athletes: Pandimensional muscularity leads to overestimation of body fat.

  • Elderly individuals: Muscle loss leads to underestimation of body fat.

• Definition of Obesity:

  • Excessive body fat relative to body weight, distinct from being overweight.

  • Associated with increased risks for conditions such as hypertension, diabetes, CHD, etc.

Calculating BMI

• Example calculation:

  • Weight = 60 kg; Height = 1.65 m

  • $BMI = \frac{60}{(1.65)^2} = 22 kg/m^2$

• Interpretation:

  • < 16: Severe underweight

  • 16 – 17: Moderate underweight

  • 17 – 18.5: Mild underweight

  • 18.5 – 24.9: Normal

  • 25 – 30: Overweight (Grade 1 obesity)

  • > 30—40: Obese (Grade 2 obesity)

  • > 40: Very obese (morbid or Grade 3 obesity)

WHO Classification for BMI

• Classification:

  • BMI 18.5 - 24.9: Normal Weight

  • BMI 25.0 - 29.9: Over Weight

  • BMI 30.0 - 34.9: Obesity Class I

  • BMI 35.0 - 39.9: Obesity Class II

  • BMI 40.0 - 49.9: Obesity Class III

Conclusions about BMI

• Conclusion:

  • BMI is a reasonable indicator of body fat in adults and children.

  • Not a direct measure of body fat, should not be used as a diagnostic tool.

  • Use BMI for tracking weight status in populations and identifying potential weight issues in individuals.

Hip Circumference

• Measurement Procedure:

  • Measure at the point of greatest circumference around hips and buttocks.

  • Measured to the nearest 0.5 cm while the subject stands, the measurer squats beside.

  • Use flexible, non-stretchable tape in contact with skin without indenting soft tissue.

Waist/Hip Ratio

• Waist circumference measurement:

  • Measured at the level of umbilicus, to the nearest 0.5 cm.

  • Subject stands erect, arms at sides, relaxed abdomen, feet together.

  • Measurement taken at the end of normal expiration.

Calculating Waist-to-Hip Ratio (WHR)

• Formula: $ext{WHR} = \frac{\text{waist (cm)}}{\text{hip (cm)}}$

• Example:

  • Waist = 30 cm; Hip = 40 cm

  • $ext{Ratio} = \frac{30}{40} = 0.75$

• Significance:

  • Central obesity predicts CHD & diabetes type II; risk increases with:

  • > 1 for men.

  • > 0.87 for women.

Mid-Upper Arm Circumference (MUAC)

• Normal MUAC ranges:

  • 20-year-old female: 23-34.5 cm

  • Male: 27.2-37.2 cm

• Challenges in older adults: sagging skin, changing fat distribution, declining muscle mass.

• Purpose: Estimates skeletal muscle mass and fat stores.

Anthropometry in Pregnant Women

Measurements

• Include:

  • Weight

  • Height

  • Mid-upper arm circumference (MUAC)

  • Skin fold thickness

• Weight Measurement Protocol:

  • Monthly up to 30 weeks gestation, then bi-weekly until the last month when it shifts to weekly.

  • Total weight gain calculated by subtracting pre-pregnancy weight from weight before delivery.

Age-related Changes in Body Size and Composition

• Changes include:

  • Loss of stature (height)

  • Decrease in weight

  • Loss of bone density

  • Loss of muscle mass (sarcopenia)

  • Decreased body water

  • Redistribution of body fat (increased fat).

Challenges with Taking Measurements [1]

Height Measurement Challenges

• Height may decrease by 1-2 cm/decade after age 50 due to:

  • Spinal compression

  • Spinal curvature (kyphosis)

  • Loss of muscle tone in back and legs.

• Alternatives for Measuring Height:

  • Arm span

  • Demi span

  • Knee height

Challenges with Taking Measurements [2]

Other Measurement Challenges

1. MUAC and skin-fold measurement inaccuracies arise due to loss of body water and compressibility.

2. Subject may be bedridden or unable to stand:

   • Most measurements become difficult or impossible.

3. Oedema prevents weight and skin-fold measurements.

Using Arm Span Instead of Height

• Correlation:

  • Arm span correlates well with height but varies by ethnicity and age.

• Implication:

  • Age-specific and ethnicity-specific equations should be used for estimating height from arm span in older adults.

Defining Elderly

• Age brackets within older adults:

  • Young old (65-74 years)

  • Old (75-84 years)

  • Oldest old (85-99 years)

  • Centenarians (100+ years)

• No strict chronological schedule for aging; varies across individuals.

Effects of Aging [1]

• Aging begins around age 30:

  • Chronic vs. Acute health conditions.

  • Normal aging vs. disease progression.

  • Perspective: "Aging is inevitable, maturing is optional."

Effects of Aging [2]

• Prevalence of Chronic Conditions in Older Adults:

  • 80% have at least one chronic health condition.

  • 50% have more than one.

• Most costly conditions:

  • Heart disease

  • Stroke

  • Cancer

  • Diabetes

• Impacts of poor access to nutritional diets on health, independence, and quality of life.

Factors Affecting the Rate of Aging

• Influencing Factors:

  • Genetics, lifestyle choices, co-morbid diseases, social environment, and economic status impacting the rate of aging.

Factors That Place Older Adults at Risk for Malnutrition

• Significant contributors to malnutrition risk include:

  • Medications

  • Chronic diseases (e.g., congestive heart failure, renal insufficiency, chronic GI diseases)

  • Depression

  • Dental disease & impaired swallowing issues

  • Reduced taste and smell recognition

  • Low socioeconomic status

  • Physical weakness

  • Social isolation

Older People at High Risk

• Findings from consultations for the World Humanitarian Summit include:

  • Many older individuals are separated from family, have physical disabilities, or are cut off from services.

  • Experience both physical and psychological distress.

  • Possess distinct health and nutritional needs.

  • Are at increased risk for abuse and neglect, particularly among older women.

Changes in Body Size and Composition with Aging

• Variations include:

  • Height loss

  • Weight loss

  • Bone density loss

  • Muscle mass and function (sarcopenia) decline

  • Decreased body water

  • Increased fat distribution changes.

Physiologic Changes Affecting Nutrition Status [1]

• Changes lead to:

  • Increased body fat and decreased lean body mass.

  • Structural changes causing fractures, decreasing physical activity and social interaction.

  • Decreased pancreatic enzyme production, affecting digestion and absorption.

  • Possible abnormal gut bacteria overgrowth impeding nutrient absorption, especially proteins and essential vitamins.

Physiologic Changes Affecting Nutrition Status [2]

• Oral changes:

  • Missing teeth and gum deterioration, affecting chewing and swallowing, leading to dysphagia.

  • Discomfort and pain in the mouth can lower food intake.

• Neurological changes:

  • Cognitive decline and stability issues may impact food and liquid intake.

• Sensory changes:

  • Taste and smell changes with age; reduction in sight, hearing, and combined loss in taste and smell.

• Renal changes:

  • Decreased kidney size and function, heightened risks for chronic kidney disease (CKD), leading to increased frailty, anemia, and depression.

Physiologic Changes Affecting Nutrition Status [3]

• Common postural conditions in elderly:

  • Scoliosis

  • Kyphosis

Nutritional Requirements of the Elderly

Key Nutritional Components:

• Vitamins

• Protein and amino acids

• Calcium

• Calories

• Best Foods for Older Adults:

  • Brightly colored vegetables and fruits

  • Whole grains

  • Low- or non-fat dairy products

  • Lean animal and vegetarian proteins

  • Spices

  • Healthy oils

  • Adequate liquids

Measurement Difficulties in Elders [1]

• Height loss of 1-2 cm per decade after age 50 caused by

  • Spinal compression

  • Spinal curvature (kyphosis)

  • Loss of muscle tone in back and legs.

Alternatives to Height Measurement in Geriatrics

• Alternatives include:

• Arm-span

  • Positively correlated to height, varies with age and ethnicity.

  • Employ age- and ethnicity-specific equations for estimating height from arm span in older adults.

• Other alternatives:

  • Demi-span

  • Knee height.

Measurement Difficulties in Elders [2]

• For MUAC and skin-folds measurements:

  • May be inaccurate due to body water loss and compressibility.

• Challenges for bedridden individuals, where most measurements become nearly impossible.

• The presence of oedema complicates weight and skin-fold measurements.

Interpreting BMI

• BMI Classification:

  • < 16: Severe underweight.

  • 16 – 17: Moderate underweight.

  • 17 – 18.5: Mild underweight.

  • 18.5 – 24.9: Normal.

  • 25 – 30: Overweight.

  • >30: Obese.

  • >40: Morbidly obese.

Defining Nutritional Status of the Elderly

• Cut-off values for elderly different from younger adults due to varying body composition.

• Insufficient research on age-related cut-offs leading to inconclusive results for determining mortality risk in older adults.

Current Position Concerning the Elderly

• Key Issues:

  • Marginalization of elderly in policy; limited or no adaptations for their needs in the food and nutrition sector.

  • Lack of mention in recent national nutritional strategies and inadequate social pension provisions.

What Can Be Done for the Elderly

• Recommendations for Improved Care:

  • Integrate nutrition into comprehensive geriatric assessments.

  • Establish efficient nutrition screening programs tailored for older adults.

END OF SESSION