Energy balance and BMR flashcards

What is energy balance?

Energy balance is the relationship between energy intake (calories consumed) and energy expenditure (calories burned). Maintaining energy balance is crucial for weight management.

Energy intake vs. energy expenditure.

- Energy intake: calories from food. - Energy expenditure: calories burned. - Balance impacts weight.

What happens in positive energy balance?

In positive energy balance, energy intake exceeds energy expenditure, leading to weight gain over time.

Fill in the blank: Negative energy balance results in _____.

weight loss

True or False: Energy balance is only about diet.

False. It includes both diet and physical activity.

List components of energy expenditure.

- Basal Metabolic Rate (BMR) - Physical Activity - Thermic Effect of Food (TEF)

What factors affect energy expenditure?

Factors include age, gender, body composition, and activity level.

Calculate total daily energy expenditure (TDEE): 2000 kcal BMR + 500 kcal activity.

TDEE = 2000 + 500 = 2500 kcal.

What is the role of thermic effect of food (TEF)?

TEF refers to the energy required to digest, absorb, and metabolize food; typically 10% of caloric intake.

True or False: Muscle tissue burns more calories than fat tissue.

True. Muscle is metabolically active, increasing overall energy expenditure.

What is homeostasis in energy balance?

Homeostasis in energy balance refers to the body's ability to maintain stable weight by adjusting intake and expenditure.

Name a consequence of prolonged negative energy balance.

Potential muscle loss and decreased metabolic rate.

How does physical activity impact energy balance?

Physical activity increases energy expenditure, helping to create a caloric deficit for weight loss.

Fill in the blank: A caloric deficit leads to _____.

weight loss

Compare energy balance during dieting vs. maintenance.

Dieting: negative energy balance needed. Maintenance: energy intake equals expenditure.

What is a common mistake in energy balance thinking?

Overestimating calories burned during exercise and underestimating food intake.

What is Basal Metabolic Rate (BMR)?

BMR is the number of calories your body needs at rest to maintain basic physiological functions like breathing and circulation.

How is BMR typically calculated?

BMR can be calculated using the Mifflin-St Jeor equation: For men: $\displaystyle BMR = 10 \times \text{weight (kg)} + 6.25 \times \text{height (cm)} - 5 \times \text{age (y)} + 5$ For women: $\displaystyle BMR = 10 \times \text{weight (kg)} + 6.25 \times \text{height (cm)} - 5 \times \text{age (y)} - 161$

True or False: BMR is the same for everyone.

False. BMR varies based on factors like age, sex, weight, height, and muscle mass.

Fill in the blank: BMR decreases with __________.

age and loss of muscle mass.

What does BMR indicate?

BMR indicates the minimum caloric requirement to sustain basic bodily functions at rest.

Why is BMR important for weight management?

BMR helps determine daily caloric needs, aiding in creating a caloric deficit for weight loss or surplus for weight gain.

Compare BMR and Total Daily Energy Expenditure (TDEE).

BMR is the energy needed at rest, while TDEE includes all calories burned throughout the day, including activity.

How does muscle mass affect BMR?

Higher muscle mass increases BMR because muscle tissue requires more energy to maintain than fat tissue.

Calculate BMR for a 25-year-old woman, 65 kg, 170 cm.

Using Mifflin-St Jeor: $\displaystyle BMR = 10 \times 65 + 6.25 \times 170 - 5 \times 25 - 161$ Results in approximately 1,400 calories/day.

What factors can temporarily increase BMR?

Factors include stress, fever, and certain medications.

True or False: BMR remains constant throughout life.

False. BMR typically declines with age and changes in body composition.

What role does thyroid hormone play in BMR?

Thyroid hormones regulate metabolism; low levels can decrease BMR, while high levels can increase it.

List two methods to measure BMR.

- Indirect calorimetry - Predictive equations (like Mifflin-St Jeor)

What is the significance of knowing your BMR?

Knowing your BMR helps tailor diets and exercise programs to meet personal health goals.

How does hydration status affect BMR?

Dehydration can lower BMR because water is essential for metabolic processes.

Fill in the blank: BMR is usually expressed in __________.

calories per day.

What happens to BMR during prolonged fasting?

BMR decreases as the body conserves energy and reduces metabolic rate.

List three factors that decrease BMR.

- Aging - Low muscle mass - Hormonal changes

How can physical activity influence BMR?

Regular exercise can increase muscle mass, which can raise BMR over time.

What is the average BMR for adult women?

Average BMR for adult women is typically around 1,600 calories/day.