human nutrition

basal metabolism

calories needed for basic physiological function that are necessary to maintain life

thermic effect of food

energy needed for digestion, absorption, and metabolism

physical activity

voluntary activities includes exercise, day to day activities and fidgeting

how much does basal metabolism contribute to energy expenditure

60-70%

how much does thermic effect of food contribute to energy expenditure

5-10%

how much does physical activity contribute to energy expenditure

25-40%

basal energy expenditure

\-Amount of kcal needed for basal metabolism over 24 hours

\-Measured when the person is resting, awake, fasting and in a warm, quiet room

resting energy expenditure

\- Measured when the person is resting, awake, in a warm quiet room but is NOT fasting

\- 6% higher than BEE

what factors affect the basal metabolic rate

Surface area, Body composition, Age, Thyroid hormone, Growth, Environmental temperature, Physiological stress, Fasting and starvation, Nicotine, Caffeine and Genetics

factors that increase BMR

surface area, body composition, thyroid hormone, growth, environmental temperature, physiological stress, nicotine, caffeine (slightly), genetics

factors that decrease BMR

age, fasting and starvation, genetics

direct calorimetry

\-body heat released (energy leaves as heat)

\-insulated chamber surrounded by water (measures temp change of water)

indirect calorimetry

\-amount of oxygen consumed 

\-relationship between energy used and oxygen consumed

what does direct calorimetry measures

measures temp change of water heat production

what does indirect calorimetry measures

oxygen consumption

determine if person is in energy balance equilibrium

\-energy in = energy out

\-weight stable does not change

negative energy balance given the calories a person consumes and expends

\-intake is greater than expenditure 

\-2500-2000=500

positive energy balance given the calories a person consumes and expends

\-intake is less than expenditure

\-2000-2500= -500

effect on weight for negative energy balance

weight loss

effect on weight for positive energy balance

weight gain

how to calculate ideal body weight

\-female 100 lb for first 5 ft of height and for every inch over they can have 5 lb range is +- 10%

\-males 106 lb for first 5 ft, for every inch over is 6 lb, range is +- 10%

should everyone strive to be at their ideal body weight?

not always since there is a borader range for healthy weights

how calculate BMI

weight in lbs/ height in inches^2 * 703

strengths of BMI

\
\- correlates with body fat

\- more accurate than relying on weight alone

\- practical

weaknesses of BMI

\-same BMI categories can't be used in kids, weight for age or BMI for age

\-underestimates fat in frail elderly who lost muscle

\-overestimates fat in muscular individuals

Why can BMI be used to assess body weight?

weight in relationship to height

BMI where someone is underweight

18.5<

BMI where someone is at normal weight

18.5-24.9

BMI where someone is overweight

25-29.9

BMI where someone is obese

\> or \= 30

what amount of body fat is needed in men for good health?

10-22%

what amount of body fat is needed in women for good health?

20-32%

methods for determining percent body fat

\-underwater weighing or hydrostatic weighing

\-air displacement or BodPod

\-Bioelectrical Impedance

\-Dual x-ray absorptiometry (DXA)

\-skinfold measurements

principal and procedure of underwater weighing or hydrostatic weighing

principal; fat is not as dense as muscle

\-procedure: find body density by weighing a person outside of water and weighing in water

\-finds body density 

principal and procedure of air displacement or BodPod

\-principal: uses air displacement to determine body volume

\-procedure; person sits in small chamber

principal and procedure of bioelectrical impedance

\-principle: lean body mass conducts electricity better than fat

\-procedure: low-level electrical current

\-resistance to current flow

principal and procedure of dual x-ray absorptiometry

\-principal: measures fat, fat-free soft tissue and bone

\-procedure: uses x-rays

principal and procedure of skinfold measurements

\-principle: measures layer of fat under skin

\-procedure: uses multiple sites (biceps, triceps, chest, subscapular, thigh, abdomen, suprailiac crest)

\-calculation to determine body fat

obesity

having an excess amount of body fat

what diseases and conditions does obesity increase the risk of?

\-type 2 diabetes, increases insulin resistance

\-heart disease, associated with HTN and higher blood cholesterol

\-Hypertension

\-Sleep apnea, pauses in breathing while sleep, seconds to minutes

\-Gallstones

\-Bone and joint disorder- osteoarthritis

\-Cancer, uterine, prostate, colon

\-Psychological, depression, social stigmatization

two different types of body fat distribution

gynoid and android obesity

what area of the body is fat deposited in gynoid obseity

pear shape, hips, more common in women

what area of the body is fat deposited in android obesity

abdominal or central obesity, apple shape

What body fat distribution type is associated with the highest risk of disease?

android obesity

what diseases are increased by this fat distribution type?

HTN, type 2 DM and CVD

What waist circumference is used to define abdominal/android obesity?

men: >40 inches

women>35 inches

causes of obesity

\-Genetics 

\-Non exercise-associated thermogenesis-NEAT

\-Set point theory

\-Environment and Behavior 

\-Decreased physical activity (occupation, technology and transportation)

how might genetics play a role in the development of obesity?

\-body fat distribution

\-identical twin vs fraternal twins

\-identical twins raised in separate homes

\-differences in basal metabolic rate

\-differences in hormones that control appetite

what environmental factors contribute to the development of obesity?

\-obesity is increasing, yet gene pool has not changed

\-increased intake of energy dense food (more cal)

\-work more, cook less

\-larger portion size

what is the set point theory?

proposes that humans have a genetically predetermined body weight or body fat content which the body closely regulates

How much of a calorie deficit is needed to create a weight loss of about 1 lb per week?

\-500 kcal/d = 1 lb/ week

\-300 kcal/d = 1/2 lb per week

How much weight loss is needed to see improvement in disease risk?

10% weight loss in 6 months

What is the recommended rate of weight loss?

1 pounds per week

Dietary strategies for losing weight

\-calorie deficit

\-eat more vegetables, fruit, fiber

\-include protein and some fat with meals

\-use MyPlate as a guide

\-Qualities of sound weight reducing diet

\-balanced diet

Qualities of a sound weight-reducing diet

\-Promotes a safe rate of weight loss, 1 lb per week, slow and steady

\-Adaptable to special occasions and family meals

\-promote changes that can be maintained

\-focuses on health and healthy weight for life

\-all nutrients provided in adequate amount, my plate, does not promote certain foods as magical

\-reasonable cost 

\-has a behavior modification component

are low carbohydrate diets better at producing sustained weight loss compared with low calorie balance diets?

reduced kcal balanced diet is best because it is the \# of kcal consumed, not the % of the cho, pro, or fat that causes weight loss

Keto diet

\- low carb high fat diet 

\-induces ketosis

\~ketones are a byproduct of fat metabolism

\~low carbs diet

pros of keto diet

weight loss and hunger is controlled

foods allowed on keto diet

\-meat, often high in red meat

\-limited dairy-cheese

\-fats-oils, butter

\-nut butter

foods not allowed in keto diet

\-most fruits

\-most grains

\-starchy vegetables

\-legumes

cons of keto diet

\-reduced glycogen

\-loss of lean body tissue and electrolytes

\-fatigue, weakness

\-headaches

\-constipation

\-irritability

\-bad breath

\-hard on kidneys

guidelines for exercise in weight loss

\-increases calories out

\-essentials for weight loss maintenance

\-decrease the risk of heart disease independently of weight loss

\-improves mood, self esteem, relieves stress

\-in the obese it start slowly

\-10 min 3-5 days per week

\-build to 30-45 mins 5 days/week

Calorie ranges from cho, protein, fat (don't memorize exact numbers but know what is restricted and what is excessive)

\-restricted carbs< 20%

\-high protein 25-30%

\-high fat 55-65%

paleo diet

High meat intake, No dairy, grains, poultrty, salt, processed cooking. Low Iodine levels, Vit D

other benefits of exercise beside weight loss

-lower risk of disease through healthy lifestyle, balanced diet and physical activity

importance of behavior modification in weight loss

-works to change problem behavior

different techniques and examples of each behavior modification

\-self monitoring, log of what is eaten, how it made you feel

\-chain breaking, separates behavior that tend to occur together

\-stimulus control

\-contingency management, preparation for situations that may trigger overreacting

\-very low calorie diet, provides less than 800 kcal/d, under supervision, regain weight 

Usefulness/safety of fad diets

are difficult to stick with, lots of restrictions, not the best diet

Usefulness/safety of very low calorie diets (VLCD).

\-provides less than 800 kcal/d

\-must be under med supervision

\-many regain weight

what does bariatric surgery do to size of stomach?

\-reduces size of stomach

\-staple off part of stomach 

does bariatric surgery work at producing weight loss?

it does work producing weight loss

drawbacks to bariatric surgery

\-risk of surgery- reserved for those who are very obese or have comorbidities

\-lifetime change- must eat very slowly

\-nutrient deficiencies- must be monitored long time

\-should attempt other strategies first

difference between eating disorders and disordered eating

\- disordered eating is abnormal and potentially harmful eating patterns

\-eating disorders is psychological illness that involve specific abnormal eating behavior 

Anorexia

\-self enforced starvation

\-extreme weight loss

\-irritational fear of obesity

\-distorted body image

\-body weight used for self-evaluation

\-lack of recognition of the seriousness

Bulimia

\-episodes of binge eating followed by purging

\-binge, large amounts of food consumed in one sitting and lack of control

\-purge, vomiting, laxatives, enemas and excessive exercise

physical consequences of anorexia

\-death

\-cold intolerance

\-loss of heart tissue

\-development of irregular heart rhythm 

\-iron deficiency anemia

\-lanugo to regulate body temp

\-loss of menstruation 

\-low bone mineral density and osteoporosis 

physical consequences of bulimia

\-tooth decay

\-disturbances in heart rhythm

\-salivary glands swell

\-stomach ulcers

tears in esophagus

\-medications to induce vomiting toxic to heart, liver and kidney

\-death

personality traits that may occur in those with bulimia

\-symptoms are not obvious

\-many be normal weight

\-female perfectionist

\-self-evaluation influenced by body weight/ shape

triggers and causes of anorexia

\- no single cause but are certain things that increase risk

\-sociocultural factors like pressure to be thin, and unrealistic standards of beauty

\-genetic factors, tends to run in family but not genes identified

\-psychological factors, perfectionists, family dysfunction, and feeling loss of control

triggers and causes of bulimia

anxiety, binge, purge, guilt, anxiety

Behaviors individuals with anorexia may engage in.

\-dieting becomes life focus

\-hiding and storing food, spreading around plate

\-may exercise compulsively

\-deny hunger

\-excessively critical of themselves

\-may also engage in episodes of binging and purging

Behaviors individuals with bulimia may engage in.

anxiety, guilt, perfectionists, hide when eating food

binge eating

\-recurrent episodes of binge eating w/o purging

\-eat for emotional reasons, feeling out of control

\-eat in secret

\-feelings of shame

\-may be normal weight, overweight, or obese

Sings of eating disorders

\-eat in secret

\-avoid social situations where there is food

\-feel uncomfortable eating around others

\-refuse to eat

\-preoccupation w/food and body weight

\-exercise excessively

\-changes in mood

\-deny unusual eating behaviors

\-flexibility with food choices

\-eating a varied and balanced mix of foods

Female athlete triad

\-disordered eating

\-lack of menstruation/ amenorrhea

\-decreases in bone

\-common in sports where appearance is important such as figure skating, gymnastics and ballet

orthorexia

\-obsession with 'healthy' and "righteous" eating

\-fixates on identifying and eating the 'right food'

difference between orthorexia, anorexia and bulimia

\-motivation is not tied to control of weight or cal intake

\-motivation is to control what is perceived

How are eating disorders treated?

\-multidisciplinary team

\~psychological-treatment of coexisting conditions and coping skills

\~medical

\~registered dietitians

\~should be experienced in treating

\~\`complex area

\~\`many health care professionals don't feel comfortable dealing with 

\-Outpatient care or hospitalization 

\-Difficult to treat but treatable

\-Goal of nutrition counseling

\~address black and white thinking about food

vitamins

\-in general, the body is unable to synthesize enough

\-absence from diet produces deficiency symptoms

macronutrients

needed in larger amounts and provide energy

micronutrients

needed in smaller amounts and do NOT provide kcal

fat soluble vitamins

A, D, E, K

water soluble vitamins

Thiamin, riboflavin, niacin, B6, folate, B12, pantothenic acid, biotin, vitamin C

vitamins are

micronutrients

Stability and cooking practices that preserve vitamins in foods

\-water soluble are most fragile than fat soluble

\-degradation (water, heat, air, time)

water

cooking and soaking in water causes loss of water soluble vitamins

heat

higher heat destroys vitamins especially C

air

exposure to air

time

longer cooking time and time for harvest

storage and toxicity for water soluble

\-don' store a lot

\-excess are excreted in urine

\-toxicities can occur in large doses of supplements are taken but don't occur as easily as with fat soluble