Energy Balance Concepts

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What defines energy balance?

Energy expenditure is greater than energy intake

Energy intake is reduced over time

Energy intake exceeds energy expenditure

Energy intake equals energy expenditure (correct)

Which of the following factors influences energy intake?

Genetics only

Metabolic rate exclusively

Type and amount of food consumed (correct)

Duration of physical activity

What does resting metabolic rate (RMR) primarily refer to?

Total calorie intake throughout the day

Calories burned during strenuous exercise

Energy needed for maintaining normal bodily functions (correct)

Energy consumed from food only

How does the thermic effect of food (TEF) affect daily energy expenditure?

It is typically 8-10% of daily energy expenditure Signup and view all the answers

Which of the following factors does NOT influence basal metabolic rate (BMR)?

Physical activity level Signup and view all the answers

What is one of the main hormonal characteristics of polycystic ovary syndrome (PCOS)?

Excess androgen production Signup and view all the answers

Which hormone, when in low levels, can increase appetite and lead to overeating?

Leptin Signup and view all the answers

Which condition results from a loss of muscle and fat tissue due to undernutrition?

Wasting Signup and view all the answers

What percentage of deaths in children under 5 years of age in 2020 was attributed to undernutrition?

45% Signup and view all the answers

Obesity is linked to an increased risk for which of the following conditions?

High blood pressure Signup and view all the answers

What genetic disorder is characterized by an uncontrollable feeling of hunger?

Prader-Willi syndrome Signup and view all the answers

Which of the following is not a consequence of undernutrition?

Heightened cognitive abilities Signup and view all the answers

What are micronutrient deficiencies primarily associated with?

Deficiency of vitamins and minerals Signup and view all the answers

Which medication type is commonly associated with weight gain?

Corticosteroids Signup and view all the answers

Which type of cancer is NOT typically associated with obesity?

Lung cancer Signup and view all the answers

Which of the following is a potential pregnancy complication due to undernutrition?

Preeclampsia Signup and view all the answers

How does undernutrition affect the immune system?

It weakens it Signup and view all the answers

What is a potential consequence of obesity in men?

Low sperm count Signup and view all the answers

Obesity can result in which of the following pregnancy complications?

Preeclampsia Signup and view all the answers

Which condition is characterized by impaired growth and cognitive deficits due to undernutrition?

Stunting Signup and view all the answers

What can malabsorption lead to in relation to undernutrition?

Deficiencies in essential nutrients Signup and view all the answers

Which factor contributes to a higher BMR due to increased muscle mass?

Lean body mass Signup and view all the answers

What typically causes a slowdown in metabolism as people age?

Loss of muscle tissue Signup and view all the answers

Which of the following best describes the relationship between gender and metabolism?

Men have faster metabolisms than women. Signup and view all the answers

What is the primary distinction between BMR and RMR?

BMR is the minimum calories needed for basic functions at rest. Signup and view all the answers

What is one possible hormonal cause of obesity?

Hypothyroidism Signup and view all the answers

Which of the following environmental factors can affect BMR by requiring the body to work harder?

Changes in environmental temperature Signup and view all the answers

What is a primary effect of genetics on metabolism?

It can predispose individuals to varying metabolic rates. Signup and view all the answers

What role does physical activity play in relation to BMR?

It can increase muscle mass and therefore BMR. Signup and view all the answers

What is a primary characteristic of anorexia nervosa?

Severely restricted food intake Signup and view all the answers

What behavior is commonly associated with bulimia nervosa?

Binge eating followed by purging Signup and view all the answers

Which eating disorder is characterized by a restrictive eating pattern not attributed to another medical condition?

Avoidant/restrictive food intake disorder (ARFID) Signup and view all the answers

What is cachexia commonly associated with?

A syndrome of wasting and weakness Signup and view all the answers

How can gastrointestinal disorders lead to undernutrition?

By impairing absorption of nutrients Signup and view all the answers

Which side effect of cancer treatment can contribute to undernutrition?

Nausea and vomiting Signup and view all the answers

What mechanism does cancer employ that can deprive other cells of nutrients?

Direct malnutrition caused by cancer cells Signup and view all the answers

How can diarrhea related to gastrointestinal disorders affect nutrient status?

It increases nutrient losses Signup and view all the answers

Study Notes

Energy Balance

Energy balance is the state where energy intake equals energy expenditure
This concept shows how body weight changes over time based on intake and expenditure.
When these are in balance, body weight stays stable.
A positive energy balance means energy consumed is greater than energy expended, leading to weight gain.
A negative energy balance means energy consumed is less than energy expended, leading to weight loss.

Definition of Energy Intake

Energy intake is the amount of energy a person takes in through food and drinks
It's influenced by the type and amount of food consumed, and the frequency of eating.

Definition of Energy Expenditure

Energy expenditure is the amount of energy spent through physical activity, and bodily functions.
It's influenced by the amount of exercise, and metabolism (the body's rate of converting food to energy).
Factors influencing metabolism include age, sex, and genetics.

Components of Energy Expenditure

Basal Metabolic Rate (BMR): the energy expenditure needed for maintaining normal bodily functions and homeostasis. Accounts for 60-75% of total energy expenditure
Thermic Effect of Food (TEF): the energy required for digesting, absorbing and metabolizing food. Accounts for 5-10% of total energy expenditure.
Physical Activity: the energy used from movement like exercise. Accounts for 15-30% of total energy expenditure.

Factors Affecting BMR

Body Composition: Lean body mass (especially muscle mass) requires more energy to maintain, thus contributing to a higher BMR.
Age: Metabolism generally slows with age due to loss of muscle tissue and changes in hormonal and neurological processes.
Body Size: Larger bodies with more metabolizing tissue have higher BMR.
Gender: Men generally have faster metabolisms (higher BMR) than women, partly due to their larger size.
Genetics: Genetic predisposition can partly determine metabolic rate.
Hormonal Factors: Hormonal imbalances(e.g. hypo/hyperthyroidism) affect metabolism, influencing BMR.
Environmental Factors: Temperature changes can affect BMR as the body works harder to maintain its normal temperature.
Drugs: Certain substances (e.g. caffeine, nicotine) can increase BMR, while some medications can affect metabolism.
Physical Activity: Increases muscle mass, thus increasing BMR.

BMR vs RMR

BMR and RMR are similar, but BMR is measured under more strict conditions
BMR is measured in a darkened room, after 8 hours of sleep and 12 hours of fasting and in a resting or reclining position. RMR has fewer restrictions and is easier/quicker to measure.

Male & Female Resting Metabolic Rate

An equation is used to estimate BMR
Values for weight, height, and age are inputted for the calculation

Obesity

Obesity is defined as having a body mass index (BMI) of 30 or greater.
BMI is used to determine if a person is maintaining a healthy body weight.
Body composition assessments (e.g. underwater weighing, BIA, DXA, Bod Pod, skinfolds, waist circumference) are ways to measure healthy body weight.

BMI Values and Weight Status

A table showing BMI values and their corresponding weight statuses.

Causes of Obesity

Genetics: Some people are genetically more predisposed to obesity.
Diet: Eating too much calorie-dense food and drinks is a major cause of obesity
Physical Activity: Lack of exercise can contribute to obesity.

Medical Conditions Associated with Obesity

Hypothyroidism (low thyroid hormone levels).
Cushing Syndrome (high cortisol levels)
Polycystic Ovary Syndrome (PCOS).
Prader-Willi Syndrome.
Other eating disorders like anorexia and bulimia as well as conditions associated with malabsorption.

Under-nutrition

Under-nutrition, involves having too little of essential nutrients.
It can lead to several health problems, including wasting, stunting and micronutrient deficiencies (e.g. anaemia, goiter, rickets).
It is a major cause of child mortality.

Causes of Undernutrition

Malabsorption (e.g., celiac disease, Crohn's disease).
Anorexia Nervosa (an eating disorder characterized by an extreme fear of weight gain, resulting in severely restricted food intake).
Bulimia Nervosa(an eating disorder characterized by binge eating followed by purging behaviors, such as vomiting, laxative use, or excessive exercise).
Other eating disorders (e.g. avoidant/restrictive food intake disorder (ARFID), pica)
Cancer (Cancer cells consuming a lot of nutrients, leaving limited supply to other tissues and cells)
Chronic infections (such as HIV/AIDS, tuberculosis, and malaria increase metabolic demands and diminish the body's capacity to absorb essential nutrients.)
Gastrointestinal disorders(such as Crohn's disease and ulcerative colitis)

Health Consequences of Under-nutrition

Impaired growth and development.
Weakened immune system
Increased risk of chronic conditions(e.g., heart disease, stroke, cancer)
Pregnancy complications(such as preeclampsia, low birth weight and miscarriage)

Malnutrition

Malnutrition refers to a nutrient imbalance, which can take the form of having too little or too much nutrient intake.
Undernutrition is more common than overnutrition in developing countries.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the principles of energy balance, including definitions of energy intake and expenditure. Understand how these concepts affect body weight and the influence of various factors on metabolism and energy usage.