Human Growth and Development Nutrition

Growth and Development

• Increased energy expenditure during infancy, childhood, adolescence, pregnancy, and lactation

Thermic Effect of Food

• Energy required for digestion, metabolism, and storage of nutrients
• Occurs within a few hours of a meal
• Approximately 10% of the energy value of food
• Protein has the highest thermic effect at 20-30%, fat at 5%, and carbohydrates at 5-10%

Physical Activity

• Energy required to perform physical work of any kind
• Includes non-exercise activities (NEAT) such as talking, sitting, and fidgeting
• Factors influencing energy expenditure:
  • Intensity: how strenuous the activity is, related to O2 consumption
  • Duration: the longer the duration, the higher the energy expenditure
• Physical activity level (PAL): energy expended from physical activity expressed as a percentage of BEE
• Categorized as sedentary, moderate, or vigorous activity

Measuring Energy Intake and Expenditure

• Measured in a laboratory research setting using a bomb calorimeter
• Practical methods include simple calculations and indirect calorimetry
• Scientific databases contain analysis of nutritional content of foods
• Predictive equations estimate energy expenditure when indirect calorimetry is not available

Energy Balance

• Balance occurs when energy intake approximates energy expenditure
• For most healthy adults, energy balance fosters weight maintenance
• Negative energy balance: insufficient energy available, leading to weight loss
• Positive energy balance: energy intake exceeds energy expenditure, leading to weight gain

Factors Influencing Energy Balance

• Biology-genetics and hormones
• Food types-food behavior, liquid forms of intake, protein-containing foods

Recommendations for Energy Intake and Expenditure

• Institute of Medicine (IOM) describes estimated energy requirements (EER) for adults and children
• EER considers important body functions, growth and development, physical activity, and good health
• Physical activity (PA) levels for different lifestyles defined by the World Health Organization (WHO) as:
  • Sedentary: little to no exercise or physical activity beyond daily living
  • Low active: light physical activity such as walking or standing for at least 2 hours per day
  • Active: moderate physical activity such as brisk walking, cycling, or gardening for at least 30 minutes per day
  • Very active: high levels of physical activity such as running, swimming, or engaging in sports for at least 60 minutes per day

Physical Activity Recommendations

• Children: at least 60 minutes of moderate physical activity on most days, minimizing sedentary behavior
• Adults: at least 30 minutes of moderate activity on most days, with some requiring up to 60 minutes to prevent weight gain

Energy Balance in Children

• Normal growth and development indicates that energy needs are being met
• Insufficient energy intake leads to slowed growth rate (growth faltering)

Wellness Concerns

• Positive energy balance can lead to weight gain, increasing the risk of diseases such as DM or hypertension
• Assess reason for energy imbalance, including medical reasons and energy intake and expenditure

Energy Balance in Critical Illness

• Nutrition intervention is essential for critically ill patients with altered metabolic needs
• Requirements for protein, calories, and micronutrients are increased during physiologic stress and may continue during rehabilitation