HNSC 2170: Unit 7

What is energy balance and imbalance?

Imbalance between energy in and energy out.

What happens during feasting?

Energy in (consumption) is greater than energy out (energy excess). Excess energy (fat, carbs, protein, alcohol) is stored as body fat.

What happens during fasting?

Energy in is less than energy out (energy deficit). The body gets energy from tissue stores (carbs, fat, proteins).

What are the effects of rapid initial weight loss and lean body mass during fasting?

Voluntary weight loss and lean body mass loss. Involuntary weight loss is considered starving.

What is energy balance?

Energy in (kcal) is equal to energy out (kcal). Food energy intake is equal to energy expenditure. Change in energy stores is equal to energy in (kcal) minus energy out (kcal).

How much energy (kcal) needs to be expended in excess of need to lose approximately 1 lb of body fat?

Every 3500 kcal expended in excess of need can lead to a loss of around 1 lb of body fat.

How much of energy expenditure does basal metabolism account for?

Basal metabolism accounts for 50-65% of energy expenditure.

What activities are included in basal metabolism?

Involuntary activities to maintain life, such as circulation, respiration, temperature maintenance, hormone secretions, nerve activities, and new tissue synthesis. Excludes digestion and voluntary activities.

What is basal metabolic rate?

The rate at which the body expends energy for increased activities. It varies from person to person and is measured when awake and lying still, at a good temperature, after restful sleep and an overnight fast.

What factors can affect basal metabolic rate?

Factors that can increase BMR include being in a growing stage (children, adolescents, pregnant women), having a higher lean body mass (fit people, males), engaging in physical activity and strength activities, being tall (larger surface area for weight), having a fever or being stressed. Factors that can decrease BMR include loss of lean body mass, fasting, malnutrition, and sleeping.

What is the second largest component of energy expenditure?

Physical activities, which are intentional and voluntary movements of muscles such as walking, sitting, and running. It varies and the number of calories spent depends on muscle mass and body weight.

What is the thermic effect of food?

The energy expenditure associated with the digestion, absorption, and metabolism of food. It accounts for approximately 10% of energy expenditure.

What is the relationship between muscle mass and calorie expenditure?

↑muscle mass = ↑kcal spent

What factors affect the amount of calories spent during activity?

↑length, frequency, intensity of activity

What factors affect the body's basal metabolic rate (BMR)?

Age, height, body composition, fever, stresses, environment temperature, fasting/starvation, malnutrition, hormones, smoking & caffeine, sleep

How does age affect BMR?

↓lean body mass w/ age = ↓BMR

How does height affect BMR?

↑height (tall) = ↑BMR

How does body composition affect BMR?

↑lean tissue = ↑BMR, ↑fat tissue = ↓BMR

How does fever affect BMR?

↑BMR

How do stresses affect BMR?

+ diseases & certain drugs = ↑BMR

How does environment temperature affect BMR?

Heat & cold = ↑BMR

How does fasting/starvation affect BMR?

↓BMR

What is BMR (Basal Metabolic Rate)?

amount of energy it takes to keep your body functioning at rest

How does malnutrition affect BMR?

↓BMR

How do hormones affect BMR?

Thyroxin can ↑BMR or ↓BMR, premenstrual hormones slightly ↑BMR

How do smoking and caffeine affect BMR?

↑BMR

How does sleep affect BMR?

↓BMR

What factors should be taken into account when calculating energy requirements?

Gender, growth, age, physical activity, body composition & size

How does gender affect energy requirements?

Women have ↓BMR than men, menstrual hormones may ↑BMR

How does growth affect energy requirements?

Children, adolescents, pregnant women have ↑BMR

How does physical activity affect energy requirements?

↑PA will use more energy

What is the formula for calculating BMI?

BMI = weight (kg) / height (m^2) or weight (lb) / height (in^2) x 703

What are the BMI classifications for adults?

Underweight: below 18.5, Normal: 18.5-24.9, Overweight: 25-30, Obese (class I): 30-35, Obese (class II): 35-40, Extreme obesity (class III): >40

What are the limitations of BMI?

Does not show how much weight is fat, does not show where fat is located, not suitable for some athletes

What are the BMI ranges for different populations?

Body builders: BMI in obese range; Pregnant & lactating women: ↑weight is normal during childbearing; Adults over 65: BMI values based on data from younger people; Adjusted BMI ranges for older adults exist.

What happens to height as people age?

People tend to lose height as they age.

What is the significance of BMI values between 23-29?

↓Mortality rate; not associated with ↑risk.

What is the relationship between BMI and health?

Many in the 'normal' range were unhealthy; Many in 'very obese' were healthy.

What are the methods for assessing body weight and composition?

Anthropometry: direct body measurements (waist circumference, fat fold test); Skinfold: estimate of total body fat & location of fat using callipers.

What is visceral fat?

Fat stored deep in abdominal cavity, not subcutaneous fat in skin.

What is central obesity?

↑Fat around trunk/belly, aka abdominal fat; Common in men; ↑Risk of CVD, stroke, DM, HTN, some types of cancers.

What is lower body fat?

↑Fat in hips, legs; Common in women; Not usually associated with chronic diseases.

What is the significance of waist circumference?

Indicator of fat distribution & central obesity; ↑Risk of central obesity problems; Women: >35 in; Men: >40 in.

What role does genetics play in the development of obesity?

Genetics influence energy usage, eating behaviors, and body composition.

What is the role of lipoprotein lipase (LPL) in obesity?

LPL allows for fat storage in fat and muscle cells.

How does leptin contribute to obesity?

Leptin is an appetite suppressing hormone that conveys information about body fatness to the brain.

What is the function of ghrelin in obesity?

Ghrelin is an appetite stimulating hormone that promotes energy storage and stimulates appetite.

What are some other theories that explain the development of obesity?

Other theories include fat cell development, set-point theory, and intestinal bacteria.

How does fat cell development contribute to obesity?

The theory suggests that the number and size of fat cells determine body fatness.

- Fat cells increase in number in childhood and typically taper off in adulthood

What is the set-point theory?

The set-point theory proposes that the body maintains a certain weight through internal controls.

How does intestinal bacteria influence obesity?

Changes in intestinal microbiota may influence energy balance and contribute to weight changes.

What are some environmental stimuli that contribute to obesity?

Factors such as overeating, learned behavior, and physical inactivity can contribute to obesity.

What is overeating?

Overeating refers to consuming more food than the body needs.

What is appetite?

Appetite is the psychological desire to eat.

What is satiety?

Satiety is the feeling of fullness and satisfaction after a meal that inhibits further eating.

What are factors that contribute to overeating?

Readily available, inexpensive, heavily advertised, tasty

How can thinking a food is a good value lead to overeating?

People may eat more than they need

What types of food can contribute to overeating?

Fast food (energy dense), restaurant meals

What are some tips for reducing portion sizes?

Decrease portion sizes, choose less energy-dense foods

What types of foods should be included in a healthy diet?

Fruits, vegetables, legumes, whole grains

What are hunger and appetite?

Hunger is a physiological desire to eat, appetite is a psychological desire to eat

What can cause us to ignore hunger or over-respond to it?

Psychological stimuli, learned behavior

What are some emotional factors that can influence eating?

Fear of starvation, cravings, expressing feelings through eating

How does physical inactivity affect nutrient intake?

Moving too little can lead to nutrient deficiencies

What is a sedentary lifestyle?

A lifestyle with little physical activity, such as excessive screen time or sitting jobs

What are the risks of taking health products for weight loss?

No evidence for long-term weight loss, potential interactions and adverse effects

What are some risks of buying weight loss products online?

No examination by healthcare professional, unreliable sources, risk of counterfeit products

What is the risk of using weight loss products for purposes other than intended?

Using products 'off label' can be risky, such as using laxatives for weight loss

Why is assuming a product is safe because it's 'natural' a risk?

Natural products can still have risks, such as high concentrations of ingredients

What is energy imbalance?

When there is a disparity between energy intake and energy expenditure.

What are the three components of energy expenditure?

Basal metabolic rate, physical activity, and thermic effect of food.

What factors affect the body's basal metabolic rate?

Age, gender, body size, body composition, and genetics.

What factors should energy requirement calculations take into account?

Physical activity level, age, gender, and body composition.

How is body mass index (BMI) calculated?

BMI = weight (kg) / height (m^2).

What role may genetics play in the development of obesity?

Genetic factors can influence metabolism, appetite, and fat storage.

What are the other theories that may account for the development of obesity?

Set point theory, thrifty gene theory, and leptin resistance.

What environmental stimuli may play a role in the development of obesity?

Food availability, portion sizes, sedentary lifestyle, and marketing.

Define appetite.

The psychological desire to eat.

What are the three lifestyle components required for healthy weight loss?

Balanced diet, regular physical activity, and behavior modification.

What are some healthy weight loss strategies?

Portion control, mindful eating, and gradual weight loss.

What is the difference between weight normative and weight inclusive approaches?

Weight normative focuses on weight loss, while weight inclusive promotes health at any size.

What are the benefits and recommendations for physical activity?

Improved cardiovascular health, weight management, and at least 150 minutes of moderate-intensity exercise per week.

what is moderate-intensity activities?

cause you to sweat a little and to breathe harder. Examples include brisk walking, water aerobics, bike riding, and gardening.

What is vigorous-intensity activities?

cause you to sweat more and be "out of breath." Examples include jogging, swimming laps, aerobics, hiking, and cross-country skiing.

How is behavior modification used for weight loss?

Changing habits and behaviors related to eating and physical activity.

What are some healthy weight gain strategies?

Increased calorie intake, resistance training, and balanced nutrient intake.

Where does energy intake come from?

Foods and beverages

What is basal metabolic rate (BMR)?

Sum of involuntary activities to maintain life

What does BMR exclude?

Digestion and voluntary activities

What is voluntary activity?

Intentional activities conducted through muscle movements

How long does the thermic effect of food last?

Approximately five hours after a meal

What is the largest energy expenditure for most people?

Basal metabolism

What is the second largest energy expenditure for most people?

Voluntary activity

What is the third largest energy expenditure for most people?

Thermic effect of food

How is energy expended in the body?

Basal metabolic rate, voluntary activity, thermic effect of food

What is Estimated Energy Requirement (EER)?

A calculation used to determine the number of calories your body needs.

Why is gender important in calculating energy requirements?

Because body composition differs between men and women.

Why is growth important in calculating energy requirements?

Because BMR is higher during periods of growth.

Why is age important in calculating energy requirements?

Because energy requirements decrease as we age.

Why is physical activity level important in calculating energy requirements?

Because physical activity uses more energy.