HNSC Unit 9

energy balance, weight, health

Energy Balance

• balance occurs when energy in = energy out

Hunger

• physiological need to eat, sensation that demands relief

Appetite

• physiological desire to eat, learned motivation

Satiation

• perception of fullness that builds throughout the meal

Satiety

• perception of fullness that lingers after meal (inhibits eating until next meal)

Estimating Energy Needs

• quick and easy estimation:

  • males: body weight in kgx24 =kcal/day

  • females: body weight in kgx22 = kcal/day

Hormones

• leptin

  • appetite suppressing hormone produced in fat cells

  • operates on feedback mechanism

External Cues to Overeat

• wide variety delectable foods

• human sensations/emotions

• time of day

• stress

• food:

  • pricing, availability, advertising

• physical activity

Energy Expenditure

• 50-65%: BMR (basal metabolic rate: all activities to sustain life)

• 25-50%: voluntary activity

• 5-10%: thermic effect of food (increased metabolism for ~5 hours after eating a meal)

Factors that Affect Basal Metabolic Rate

• age

• height

• growth

• body composition

• fever, stress

• environmental temp

• fasting

• thyroxin

Anthropometry

• waist circumference

  • healthy: <102 cm for males, <88cm for females

  • central obesity (android, upper body, apple shape)

• fat fold or skin fold using calipers

Body Density

• lean tissue is denser than fat

  • underwater weighing (body volume and density)

• conductivity

  • bioelectrical impedance (BIA): lean tissue and water conduct electrical current

Radiographic

• dual energy X-ray absorptiometry (DEXA): for total body fatness, fat distribution, and bone density

Body Mass Index (BMI)

• used for adults over 20

• weight in kg/height in m²

• <18.5 = underweight

• 18.5-24.9 = healthy weight

• 25-29.9 = overweight

• 30-34.9 = obese class 1

• 35-39.9 = obese class 2

• >40 = obese class 3

Correlation of BMI with Mortality

• all cause mortality increases at very low BMI and high BMI

• moving from overweight to normal weight → not much change in risk

• moving from obese to normal weight → big change in risk

Factors Affecting Weight

• genetics

• age

• hormones

• some meds

• medical conditions

• family and culture

• social life

Determinants of Health

• a broad range of personal, social, economic, and environmental factors that determine individual and population health

Health Inequality

• differences in the health status of individuals and groups

Health Inequity

• health inequalities that are unfair or unjust and modifiable

  • e.g. canadians who live in remote or northern regions do not have the same access to nutritious foods such as fresh fruits and veggies as other canadians

Weight Cycling - Increases

• mortality/risk of death

• risk of coronary heart disease

• type 2 diabetes and cancer

• over eating in stress

• inflammation

• emotional distress

Weight Cycling - Decreases

• immune function

• metabolic rate

• physical activity

• muscle mass

• self-esteem

Weight Inclusivity Approaches

• eat well

• be active

• good sleep

• quit smoking

• stress management

• have fun

• see a dr

Weight Normative

• people are expected to be 1 size and goal is to attain the size defined as worthy/ideal

• if some people must maintain restriction/hunger to maintain lower weight, that is prescribed

Weight Inclusive

• people are expected to be a range of sized

• goal is to accommodate the needs of people of all sizes

• no one is expected to be hungry and all sizes are prescribed adequate nutrition

Anorexia Nervosa

• may be obsessed with thinness and are often intensely afraid of gaining weight

• can be a range of weight

• they eat very little and will resist easting when they are hungry

• they may feel like their bodies are larger than they are

• certain ways of eating and exercising

• highest death rate

Bulimia Nervosa

• will try to restrict their food intake in some way then feel guilty

• out of control eating is binge eating

• try to vomit after eating to rid of calories

Binge Eating Disorder

• almost all people with this have a history of dieting

• they may have grown up in a larger body than considered desirable and felt pressure to be smaller

• may lead to binge eating after dieting