Human Nutrition - Exam 3

lbs to kg

divide by 2.2

aggressive treatments of obesity

drugs low calorie diet surgical treatment

factors affecting fat utilization

duration of activity (beginning activity uses fatty acids, after 20 minutes uses body fat) intensity of activity (as intensity increases, we use less fat; need oxygen to break down fat) training (the better trained muscles use more fat)

when is prevention of excess weight gain most effective?

during the growing years of childhood and adolescence

protein synthesis during and after activity

during: protein synthesis is suppressed - muscles use amino acids for fuel after: protein synthesis accelerates

what are the three main categories of thermogenesis

energy expended for: basal metabolism physical activity food digestion and absorption (thermic effect of food)

ATP

(adenosine triphosphate) main energy source that cells use for most of their work - delivers instant energy - present in small amounts in all tissues - required for muscle contraction

thermic effect of food

estimate of the energy required to process the food you eat - digestion, absorption, utilization of food and heat produce - affected by food comp and frequency of eating

what is excess energy stored as?

fat

ectopic fat

fat that accumulates outside of adipose tissue contributes to the many diseases associated with obesity

during rest, the body derives more than half of its ATP from the oxidation of ____________

fatty acids

what affects energy requirements

gender growth age physical activity body comp body size

glucose is stored in the liver and muscles as what

glycogen

drugs for weight loss

have to be taken with lifestyle changes diuretics amphetamines sibutramine phenylpropanolamine benzocaine laxatives orlistat

what kind of diets help people work out for long periods of time

high carb

factors affecting glycogen storage and use

how much carbohydrates a person eats - high carb diets enhance endurance by ensuring ample glycogen stores how long glycogen stores last depend on intensity and duration of activity - hard intensity uses the lactic acid system to break down glucose to pyruvate anaerobically conditioned muscles rely less on glucose and more on fat

when protein synthesis is greater than degradation, a person can gain muscle in a condition called __________

hypertrophy

hydration before/during/after exercise

important before drink water during drink some but not a lot after drink to replace

when we eat more we ________ fat cell numbers, and when we lose weight, the fat cells ________.

increase shrink

activity

intensity of exercise and body size - physical activity helps keep lean tissue

When do fat cells increase most rapidly?

late childhood and early puberty

the aerobic system

low intensity or long activities - carbohydrates, fats, and some amino acids are continuously oxidized to ensure an uninterrupted supply of ATP

android

mainly men body fat is accumulated in the upper body more risk

gynoid

mainly women body fat accumulated in lower body harder to lose

fast way to calculate basal metabolism

males : 1.2 kcals/kg/hr females : 0.9 kcals/kg/hr (0.9 or 1.2) x weight in kg x 24 hrs

ideal body weight

men: 106 lbs for 5 ft plus 6 lbs for every 1 inch over women: 100 lbs for 5 ft plus 5 lbs for every 1 inch over + 10% for large frame size - 10% for small frame size

what kind of fat is most/least harmful

most harmful: intra-abdominal fat (central or upper body) least: lower body fat (around hips and thighs)

what is the primary source of glucose

muscle glycogen

treatments for obesity - reasonable treatments

new philosophy: small moderate changes promote better health modest loss will lower cholesterol and blood pressure goal: 5-10% weight loss over 6 months is reasonable

why is it hard to maintain low body weight

number of fat cells doesn't decrease when weight is lost

where is the other spots where the body stores fat?

organs (heart, liver)

the body adapts to physical activity, responding to physical activity ___________ by building structures to support the activity

overload

uncoupling proteins

prevent energy from being converted to ATP, instead oxidation gives off heat - so affects basal metabolism - present in the mitochondria - white fat and other tissues have these - increases metabolic rate and energy expenditure - abundant in brown adipose, bc high number of mitochondria

as fat cells enlarge, it stimulates cell __________, meaning the number of cells increases

proliferation

LDL (lipoprotein lipase)

promotes fat storage in fat and muscle cells found on the surface of cells lining muscles and adipose tissue LPL breaks down VLDL's triglycerides, providing fatty acids for the msucles to use for energy and the adipose tissue to use for later obese = more LPL activity fat breakdown differs around the body after weight loss, LPL activity rises

what has the highest thermic effect?

protein protein > alcohol > carbohydrates > fat

determining frame size

r = height (cm)/wrist circumference (cm)

treatment for obesity - eating plan

reasonable energy intake (too little will cause loss of lean body mass) restrict intake to 10 kcals/pound make sure you are getting all the nutrients eat CHO, restrict fat, adequate water eat slow

gastric bypass surgery for weight loss

reduces stomach size so you can't eat as much might need supplements for vitamin or mineral deficiencies suppresses hunger alters metabolism by changing hormone secretion

if energy balance becomes negative, the number of fat cells ___________

remains the same

basal metabolism

represents the energy needed for vital body processes - depends mainly on lean tissues

meals before competition

should be carb rich avoid fiber and fat

myokines

signaling proteins secreted by working skeletal muscles that contribute to widespread beneficial effects of physical activity on body system - evoke changes in skeletal muscle and adipose tissue and organs

the number and ________ of fat cells increase when energy balance is positive

size

what factors affect eating disorders

societal family (unhealthy communication, emphasis on weight and perfection, high incidence of depression) individual (biological, personality, significant life events)

what happens to adipose cells when we lose weight

the adipose cells shrink, but the number of fat cells doesn't decrease

what happens when the diet delivers too little energy, carb, or protein?

the body uses its glycogen and fat stores to meet glucose and energy needs (also degrades lean tissue to meet protein (and glucose) needs)

lactic acid system (glycolysis)

the breakdown of glucose to pyruvate without the use of oxygen pyruvate is then converted into lactic acid can generate small amounts of ATP quickly for high intensity activity lasting up to 3 minutes

set point

the point at which controls are set (for example, on a thermostat). The set-point theory that relates to body weight proposes that the body tends to maintain a certain weight by means of its own internal controls.

body composition

the proportions of muscle, bone, fat, and other tissues that make up a person's total body weight

weight loss strategies

- small changes - moderate losses - reasonable goals - reasonable rate of weight loss

bulimia nervosa (health problems)

- subclinical malnutrition - tooth erosin - red eyes - calloused hands - clinical depression - high substance abuse rates

treatment for obesity - physical activity

to increase energy expenditure (short and long term) provides appetite control psychological benefits spot reducing (only for the abdomen) low to moderate long duration

what do fat cells store?

triglycerides

what happens when we do not have enough energy? what do we turn to for energy?

we break down what we stored - lose lean tissue and water and body fat

how to calculate BMI

weight (kg) / height (m^2) weight (lbs) / height (in^2) x 703 healthy : 18.5 - 24.9

energy balance

when energy in versus the energy out - a shift in balance causes weight changes

when do fat cells divide

when it reaches maximum size

brite adipocytes

white fat cells with brown fat cell characteristics when fat cells undergo browning (gain uncoupling proteins) - more abundant than brown fat cells in adults - can be triggered by exercise

overload

working the body harder than it is normally worked a principle of training that states for a body system to improve, it must be worked at frequencies that increase by increments

anorexia nervosa

An eating disorder characterized by an obstinate and willful refusal to eat, a distorted body image, and an intense fear of being fat - malnutrition - distorted body image - denial

density

D = weight/volume

muscle dysmorphia

a disorder characterized by an extreme concern with becoming more muscular

Adiponectin

a protein produced by adipose cells that inhibits inflammation and protects against insulin resistance, type 2 diabetes, and cardiovascular disease - inversely correlated with body fat (high body fat = less adiponectin) - secreted by body fat

leptin

a protein produced by fat cells (adipose) under direction of the ob gene, which suppresses appetite and stimulates energy expenditure - promotes negative energy balance and a decrease in body weight and fatness - acts on the hypothalamus - levels increase when body fat increases, and decreases when body fat decreases - levels decrease with food intake and increase with fasting, hunger, starvation

ghrelin

a protein produced by the stomach cells that enhances appetite and decreases energy expenditure - triggers the desire to eat; blood levels of ghrelin increase before a meal and decrease after - acts on the hypothalamus - lean people have high levels, obese people have low levels - a lack of sleep raises ghrelin levels - levels increase with increased body fat

weight cycling

a repeated pattern of losing and regaining body weight

hyponatremia hypernatremia

abnormally low/high concentrations of Na+ in the blood

adaptive thermogenesis

additional energy spent to adapt to a dramatic change - when exposed to extreme cold or heat

fat is stored in the ________ tissues

adipose

where is the first spot that the body stores fat?

adipose tissue: the body's natural storage site

what factors affect the BMR

age growth body comp fever : raises BMR stresses : environmental temperature fasting/starvation : losing lean tissue to be broken down for energy malnutrition smoking : stopping smoking raises weight caffiene sleep

obesogenic environment

all the factors surrounding a person that promote weight gain, such as increased food intake, especially of unhealthy choices, and decreased physical activity - pushes our population towards obesity

bulimia nervosa

an eating disorder characterized by episodes of overeating, usually of high-calorie foods, followed by vomiting, laxative use, fasting, or excessive exercise - more prevalent than anorexia nervosa - not as physically apparent - secretive nature - binge-purge cycle

binge eating disorder

an eating disorder in which people overeat compulsively - typically with no purging

____________ occurs when protein degradation is greater than synthesis

atrophy

estimated energy requirements

average energy intakes predicted to maintain body weight in healthy individuals also called daily energy expenditure

Choose the incorrect answer: a. Vitamin and mineral deficiencies impede performance b. Taking a vitamin or mineral supplement before a competition will improve performance, especially if the athlete has a vitamin or mineral deficiency c. Athletes consuming little food, for example, to "make weight" may benefit from a multivitamin-mineral supplement d. Supplements won't improve the performance of well-nourished athletes

b

factors that affect utilization of carbohydrates

diet (high carb diets allow endurance athletes to perform the longest) intensity (as intensity increases, glycogen is used quickly) lactic acid (cori cycle) duration of activity (first 20 minutes uses glycogen, after glycogen and fat is used) glucose after activity enlarges glycogen stores

PYY

digestive hormone that suppresses appetite - peptide from the stomach - signals satiety - released from the small intestine

characteristics of FAD diets

- limited food choices - excludes certain food groups - lacks certain nutrients - promises rapid weight loss - difficult to maintain

anorexia nervosa (health problems)

- "skin and bones" apperance - lower body temp - lanugo and loss of hair - lower basal metabolism - lower heart rate - iron deficiency, anemia, nutrient deficiencies - rough, dry, scaly, cold skin - low white blood cell count - constipation, amenorrhea - changes in neurotransmitter - mortality (heart failure) - osteoporosis

what are the three treatments for obesity

- lifestyle changes - medication - surgery

eating patterns to help lose weight

- be realistic about energy intake - emphasize nutritional adequacy - eat small portions - slow down - lower energy density of food - remember water - focus on plant based foods - choose fats sensibly

problems with a low carbohydrate diet

- constipation - nausea - fatigue - stale foul taste in mouth - loss of appetite - low blood pressure - elevated uric acid - dramatic weight loss (due to water loss)

bulimia nervosa (treatment)

- discontinuing purging and restrictive diet habits - learn to eat 3 meals a day plus snacks - treatments

anorexia nervosa (warning signs)

- focus on dieting - abnormal eating habits - eating very little food - preoccupation with food - hiding and storing food - prepares large meals for others - withdrawn from friends and family - critical of self and others - sleep disturbances and depression - may exercise compulsively

anorexia nervosa (treatments)

- intervention - nutrition therapy - psychological therapy

binge eating disorder (treatments)

- learn to eat in response to hunger - learn to eat in moderation - avoid restrictive diets - address hidden emotions - overeater anonymous - antidepressants

protein needs

0.8 g/kg body weight - more for physical activity

1 in = ? cm

2.54 cm

1 pound of fat

3500 kcalories

1 m = ? inch

39.37

A waist circumference of > ___ for men, and > ___ for women is an indicator of fat distribution and central obesity

40 35

components of energy expenditure

50-65% basal metabolism 30-50% physical activities 10% thermic effect of food

very low-calorie diet for weight loss

800 kcals : 1g protein/kg; 50g carbohydrate little to no fat, must take vitamin/mineral supplements slower fat oxidation and BMR

female athlete triad

A condition consisting of three interrelated disorders: abnormal eating patterns (and excessive exercising) followed by lack of menstrual periods (amenorrhea) and decreased bone density (premature osteoporosis)

creatine phosphate system

The energy pathway that consists of adenosine triphosphate (ATP) and phosphocreatine (PC) provides immediate energy (between 10 and 15 seconds) through the breakdown of these stored high-energy phosphates - for short and high intensity activities - is regenerated at rest

how to measure the energy released in food

bomb calorimeter - how we came up with how many kcals for protein, fat, carbs, and alcohol - food in burned, the change in temperature in water is measured to show how much energy is contained

health risks associated with body weight and body fat

cardiovascular disease diabetes (type II) cancer inflammation and metabolic syndrome