Nutritional Indices in Adults: Body Mass Index (BMI)

Nutritional Indices in Adults

• The international standard for assessing body size in adults is the body mass index (BMI).
• BMI is computed using the formula: BMI = Weight (kg) / Height (m²).
• BMI is a simple index of weight-for-height that classifies underweight, overweight, and obesity in adults.

Body Mass Index (BMI)

• BMI is defined as weight in kilograms divided by the square of height in meters (kg/m2).
• For example, an adult who weighs 70kg and is 1.75m tall has a BMI of 22.9.

Problems with BMI Use

• BMI is only a proxy indicator of body fatness.
• Factors such as fitness (muscle mass), ethnic origin, and puberty can alter the relationship between BMI and body fatness.
• BMI does not provide any indication of the distribution of body fat and does not fully adjust for the effects of height or body shape, which may be particularly important when comparing figures across ethnic groups.

Health Consequences of Obesity for Adults

• Obese individuals are at increased risk for many diseases and health conditions, including:
• All-causes of death (mortality)
• Hypertension
• High LDL cholesterol, low HDL cholesterol, or high levels of triglycerides (Dyslipidemia)
• Type 2 diabetes
• Coronary heart disease
• Stroke
• Gallbladder disease
• Osteoarthritis
• Sleep apnea and breathing problems
• Chronic inflammation and increased oxidative stress
• Some cancers (endometrial, breast, colon, kidney, gallbladder, and liver)
• Low quality of life
• Mental illness such as clinical depression, anxiety, and other mental disorders
• Body pain and difficulty with physical functioning

Dietary Constituents

• Classification by origin: foods of animal origin and foods of vegetable origin.
• Classification by chemical composition: proteins, carbohydrates, fats, minerals, and vitamins.
• Classification by predominant function: body-building foods, energy-giving foods, and protective foods.
• Classification by nutritive value: cereals, vegetables, fruits, etc.

Nutrients

• Macronutrients: proteins, fats, and carbohydrates.
• Micronutrients: vitamins and minerals.

Balanced Diet

• A diet that contains a variety of foods in such quantities and proportions that the need for all nutrients is adequately met for maintaining health, general well-being, and also makes small provisions for extra nutrients to withstand a short duration of leanness.

Principles of Constructing Balanced Diet

• Daily requirement of protein should be met (15-20% of daily energy intake).
• Fats limited to 20-30%.
• Carbohydrates rich in natural fiber should constitute the remaining food energy.
• Requirements for micronutrients should be met.

WHO Dietary Goals

• Fat should be limited to about 20-30%.
• Saturated fats should not be more than 10%.
• High consumption of refined carbohydrates should be avoided.
• Restrict sources rich in energy.
• Salt intake should be reduced.
• Proteins should account for 10-20%.
• Junk foods should be reduced.

Nutrition in Health Care

• Health problems can alter nutrition needs and lead to malnutrition.
• Hospitalized patients are at risk of malnutrition, with 40-60% of acute illness patients being malnourished, and others declining in nutrition status within 3 weeks.

How Illness Affects Nutrition Status

• Reduced food intake due to nausea, inflammation of the mouth, and medication-related GI upset.
• Interferes with digestion and absorption.
• Alters metabolism and excretion.

Identifying Risk for Malnutrition

• Nutrition screening identifies persons at risk for nutrition problems.
• Screening must be done within 24 hours after admission.
• Nutrition assessment includes medical diagnosis, medical record, physical measurements, lab reports, and diet history.

Planning Care

• The Nutrition Care Process includes nutrition assessment, nutrition diagnosis, nutrition intervention, and nutrition monitoring and evaluation.
• The Nursing Process includes assessment, nursing diagnosis, outcome identification and planning, implementation, and evaluation.

Historical Information

• Medical history includes age, gender, weight, prescription drugs, over-the-counter medications, type of illness, and dietary supplements.
• Social history includes cultural heritage, financial concerns, living situation, who prepares and shops for food, and meal patterns.

Dietary Assessment Methods

• 24-hour recall and food record are used to assess dietary intake.
• Food record is recorded over several days and includes food preparation and meal patterns.