Estimated Energy Requirement (EER): the average dietary energy intake predicted to maintain an energy balance in a healthy adult of a defined age, gender, and height whose weight and level of physical activity are consistent with good health.

Energy balance: the calories consumed are equal to the energy expended.

Variables which affect nutrient needs:

• age

• gender

• activity level

• climate

• health

• state of nutrition

To maintain weight:

• Sedentary adults require: ~30 cal/Kg/day

• Moderately active adults require: ~35 cal/Kg/day

• Very active adults require: ~40 cal/Kg/day

Energy Content of Food

The energy content of food is calculated from the heat released by the today combustion of food in a calorimeter.

• expressed in kilocalories

• carbohydrate = 4 cal/g

• protein = 4 cal/g

• fat = 9 cal/g

• alcohol = 7 cal/g

Use of Food Energy in the Body

The energy generated by metabolism of the macronutrients is used for three energy-requiring processes that occur in the body:

1. Resting metabolic rate (RMR)

2. Physical activity

3. Thermic effect of food

The number of kcal expended by these processes in 24-hour period: total energy expenditure (TEE)

Resting Metabolic Rate (RMR)

The energy expended by an individual in a resting, postabsorptive state in a thermo neutral environment.

• energy required to carry our normal body functions

  • e.g. respiration, blood flow, and ion transport

• can be determined by measuring the respiratory quotient (RQ)

  • carbohydrate = 1

  • protein = 0.84

  • fat = 0.71

• 60% - 75% of the TEE in sedentary individuals is attributable to the REE

• RMR in adults:

  • men (70kg): 1800 cal

  • women (50kg): 1300 cal

• increased in: children, males, cold climate, fever, and thyrotoxicosis

• decreased in: females, starvation, sleep, and hypothyroidism

Physical Activity

• Muscular activity provides the greatest variation in the total energy expenditure (TEE).

• The amount of energy consumed depends on the duration and intensity of the exercise.

• a lightly active person may require ~30% - 50% more calories than the RMR

• highly active person may require 100% more calories above the RMR

Thermic Effect of Food (Specific Dynamic Action (SDA))

The extra heat produced over and above the caloric value of food.

This suggests stimulation of tissue metabolism after food ingestion.

• carbohydrate = 6%

• protein = 30%

• fat = 4%

• mixed balance diet = 10%

Special Periods of Life

1. Growing period

   • Infants (up to 2 months) caloric requirements: 120 cal/kg/day

   • Children (6 months - 1 year) caloric requirements: 100 cal/kg/day

2. Pregnancy

   • caloric needs increase by 300 - 400 cal/day

3. Lactation

   • caloric needs increase by 500 - 700 cal/day

Acceptable Macronutrient Distribution Ranges (AMDR)

A range of intakes for a particular macronutrient that is associated with reduced risk of chronic disease while providing adequate amount of essential nutrients.

• carbohydrates = 45% - 65% of their total calories

• protein = 10% - 35%

• fat = 20% - 35%