Thermic Effect of Food (TEF)

Definition

The thermic effect of food (TEF) refers to the increase in metabolic rate that occurs after the ingestion of food. This effect is due to the energy required for digestion, absorption, and assimilation of nutrients. TEF accounts for a small percentage of total energy expenditure and varies depending on the macronutrient composition of the diet, with protein having a higher thermic effect compared to carbohydrates and fats.

5 Must Know Facts For Your Next Test

1. TEF typically accounts for about 10% of total daily energy expenditure, although this can vary based on factors such as body composition and meal size.
2. Different macronutrients have varying thermic effects; protein has the highest TEF, followed by carbohydrates, and then fats.
3. TEF is influenced by meal composition, as larger meals tend to produce a greater thermic effect due to increased energy requirements for processing.
4. The duration of the thermic effect can last several hours after eating, peaking around one hour post-meal and gradually declining.
5. Factors like age, sex, and individual metabolic differences can affect the magnitude of TEF in different individuals.

Review Questions

• How does the thermic effect of food influence overall energy expenditure in a daily routine?
  • The thermic effect of food contributes to overall energy expenditure by increasing metabolic rate following food intake. It represents the energy used for digestion, absorption, and metabolism of nutrients. While TEF typically accounts for about 10% of total daily energy expenditure, its impact can vary depending on dietary composition and meal size. Understanding TEF helps in comprehending how different foods can affect weight management and energy balance.
• Discuss how the macronutrient composition of a meal affects its thermic effect.
  • The macronutrient composition significantly influences the thermic effect of food. Protein has a higher thermic effect compared to carbohydrates and fats, meaning that meals rich in protein require more energy for digestion and metabolism. This difference in TEF can affect total energy expenditure throughout the day. Therefore, choosing higher protein meals may increase calorie burn post-meal compared to those high in fats or carbohydrates.
• Evaluate the role of individual differences such as age and sex in determining the thermic effect of food.
  • Individual differences such as age, sex, and metabolic rates play a crucial role in determining the thermic effect of food. Younger individuals generally have a higher metabolic rate compared to older adults, resulting in potentially greater TEF. Similarly, males often have a higher muscle mass than females, which can lead to increased energy expenditure from TEF. These variations highlight the importance of considering personal factors when assessing the impact of diet on overall energy expenditure.

Related terms

Basal Metabolic Rate (BMR):

The rate at which the body expends energy at rest to maintain essential physiological functions.

Physical Activity Level (PAL): A measure used to estimate energy expenditure based on physical activity, which is a component of total energy expenditure.

Total Daily Energy Expenditure (TDEE): The total number of calories burned by an individual in a day, which includes BMR, TEF, and calories burned through physical activity.