Nutrition Test 7

• n A
• healthful weight

• q Is
• appropriate for your age and physical development

• q Is
• maintained without constant dieting

• q Is
• based on family history of body shape and weight

• q Promotes
• good eating habits and allows for regular physical activity

• q Is
• acceptable to you

• n Underweight:
• having too little body fat to maintain health (BMI <18.5)

• n Overweight:
• having a moderate amount of excess body fat (BMI >24.9 & <29.9)

• n Obese: having an excess of body fat that adversely
• affects health (BMI >30-39.9)

• n Morbid
• obesity: body weight exceeding 100% of normal, creating a very high risk
• for serious health consequences (BMI>40)

• n Body
• Mass Index

• q Expresses
• the ratio of a person’s weight to the square of their height

• q
• BMI = weight (kg) / height (m)2

• q BMI
• = [weight (lbs) / height (inches)2] X 703

• q BMI
• values below 18.5 or above 30 have increased health risks

• q Crude
• measure to determine healthy wt. & health risks

• n Body
• composition

• q Measure
• of body fat (amt of fat or adipose tissue) and lean body mass ( amt of fat free
• tissue, or bone, muscle & internal organs)

• q Can
• be measured by

• § Underwater
• weighing

• § Skinfold
• measurements

• § Bioelectric
• impedance analysis

• § Dual-Energy
• X-Ray Absorptiometry (DEXA)

• § Bod
• Pod™

• n Fat
• distribution pattern

• q Apple-shaped
• fat patterning – upper body

• § Increased
• risk for chronic diseases

• § Men
• tend to store fat in their abdominal region

• q Pear-shaped
• fat patterning – lower body

• § No
• significant increased risk for chronic diseases

• § Women
• tend to store fat in their lower body

• n Fat
• distribution pattern:

• q Abdominal
• fat increases chronic disease risk

• q Waist-to-hip
• ratio

• § Men’s
• waist-to-hip ratio is higher than 0.90

• § Women’s
• is higher than 0.80

• q Waist
• circumference

• § Men
• above 40 in. (or 102 cm.)

• § Woman
• above 35 in. (or 88 cm.)

• n Energy
• balance

• q Occurs
• when energy intake = energy expenditure

• q Intake
• > expenditure = wt. gain (xs of ~3,500 kcals = 1 lb gain.

• q Energy
• intake is kcal from food

• q Energy
• expenditure is energy expended at rest and during physical activity. 24 hour
• TEE:

• n Basal
• metabolic rate (BMR)

• n Thermic
• effect of food (TEF)

• n Energy
• cost of physical activity

• n Basal
• Metabolic Rate (BMR)

• q Energy
• expended to maintain basal, or resting, functions of the body

• q The
• highest proportion of total energy expenditure

• q BMR
• increases with more lean body mass, during stress, and periods of growth

• q BMR
• decreases with age and during energy restriction

• n Thermic
• Effect of Food (TEF)

• q Energy
• expended to process food

• q About
• 5-10% of the energy content of a meal if mixed diet

• n Energy
• cost of physical activity

• q About
• 20-35% of someone’s total energy output each day. Dependent upon: muscles used,
• body size, intensity & duration of activity, & genetic differences

• n Calculate
• your BMR

• q Men
• = weight (kg) x 1.0 x 24 hours

• q Women
• = weight (kg) x 0.9 x 24 hours

• n Add
• the energy required to maintain your activity level to your BMR

• n About
• 25% of one’s body fat is accounted for by genetic influences

• n Different
• ideas have been suggested to explain the impact of genetics on body fat

• q Thrifty
• Gene Theory – proposes a gene causes people to be energetically thrifty; expend
• less energy thus wt gain

• q Set-point
• Theory – proposes person’s wt stays within a small range (set point); body
• compensates for changes in energy balance & keeps a person’s wt at set
• point

• n Environmental
• factors in childhood can influence

• q Food
• choices

• q Activity
• levels

• q Later
• adult behaviors

• n Childhood
• overweight increases the risk of heart disease and premature death as an adult

• n Hunger
• vs. appetite

• n Proteins
• affect the regulation of appetite and storage of body fat

• q Leptin
• acts to reduce food intake

• q Ghrelin
• stimulates appetite

• q Peptide
• YY (PYY) decreases appetite

• q Uncoupling
• proteins in brown adipose tissue increase energy expenditure

n Increase satiety (or decrease food intake)

q Hormones – serotonin, cholecystokinin (CCK)

q Increase in blood glucose levels after meal

q Stomach expansion

q Nutrient absorption from the small intestine

n Decrease satiety (or increase food intake)

q Hormones - beta-endorphins

q Neuropeptide Y

q Decreased blood glucose levels

• n Social
• factors influencing our diet include:

• q Family
• or cultural traditions

• q Holidays
• and celebrations

• q Easy
• access to high-fat foods

• q Less
• physically active lifestyles

• q Societal
• expectations of the “perfect” body

• n Healthful
• weight change requires

• q Gradual
• change in energy intake

• q Regular
• and appropriate physical exercise

• q Application
• of behavior modification techniques

• n Safe
• and effective weight loss

• q Follow
• recommended serving sizes

• q Reduce
• high-fat and high-energy food intake

• q Regular
• physical exercise: increase energy expenditure and BMR

• n Weight
• loss medications and herbal supplements:

• q May
• have dangerous side effects

• q Many
• have been removed from market

• q Should
• only be used if a person has

• n A
• BMI of 30 kg / m2

• n A
• BMI of 27 kg / m2 and other health risk factors

n Underweight: BMI below 18.5

↑ risk of infections & illness

• n Effective
• weight gain:

• q Eat
• 500 to 1,000 extra kcal/day

• q Eat
• frequently throughout the day

• q Maintain
• a balanced diet

• q limit
• fat intake: 15-30% of total energy intake

• q Avoid
• tobacco (depress appetite and increase BMR)

• q Exercise
• regularly with resistance training

• n
• Overweight

• q BMI
• between 25 and 29.9 kg / m2

• q Health
• risks: high blood pressure, heart disease, type 2 diabetes, sleep disorders

• q Many
• overweight people will become obese

• q Recommend
• healthful eating and regular physical activity to prevent additional weight
• gain, achieve a healthful weight, support long-term health

• n
• Obesity and morbid obesity

• q Obesity:
• BMI from 30 to 39.9 kg / m2

• q Morbid
• obesity: exceeds 100% normal weight

• q 5
• of the 9 leading causes of death in the US are associated with obesity

• q Multifactorial
• disease: many causes of obesity

Disorders Related to Energy Intake

• n
• Overweight and obesity – epidemic in US
• linked to many chronic diseases:

q Hypertension

• q Dyslipidemia
• - elevated total cholesterol, triglycerides, and LDL cholesterol, and decreased
• HDL cholesterol

• q Type
• 2 diabetes

• q Heart
• disease and stroke

• q
• Gallbladder disease

• n
• Overweight and
• Obesity – epidemic in US linked to
• many chronic diseases:

q Osteoarthritis

q Sleep apnea

• q Certain cancers: colon, breast, endometrial, and
• gallbladder

• q Gestational diabetes, premature fetal deaths, neural
• tube defects, and complications during labor and delivery

• q
• Depression

• n Treatments
• for obesity may include

• q Low-calorie
• diet and regular exercise

• q Prescription
• medications

q Surgery

• § Vertical
• banded gastroplasty

• § Gastric
• bypass

• § Gastric
• banding

n Physical activity: any muscle movement that increases energy expenditure

• n Leisure time
• physical activity: any activity unrelated to a person’s occupation

• q Recreational –
• hiking, walking, biking

q Competitive sports

• q Exercise –
• purposeful, planned, structured physical activity

• n Physical fitness: state of being from the interaction
• between nutrition and physical activity

n Physical fitness includes

q Cardiorespiratory fitness

q Musculoskeletal fitness

q Flexibility

q Body composition

• n Regular
• physical activity:

• q Reduces
• the risk of heart disease, stroke, high blood pressure

• q Reduces
• the risk for obesity and type 2 diabetes

• q Reduces
• the risk for osteoporosis

• q May
• reduce the risk of colon cancer

• q Improves
• sleep patterns and immune function

• q Reduce
• anxiety and mental stress

• n Despite
• the clear benefits of regular physical activity,

• q more
• than half of all US
• adults do not do sufficient physical activity

• q 16%
• of US adults admit to doing no leisure time physical activity at all

• q less
• than 30% of high school students participate in daily physical education

• n A
• sound physical fitness program

• q Meets
• your personal goals

• q Is
• fun

• q Includes
• variety and consistency

• q Appropriately
• overloads the body

• q Includes
• a warm-up and cool-down period

• n A
• sound physical fitness program meets your personal goals

• n An
• individual’s fitness program will be different if they are

• q Training
• for athletic competition

• q Working
• toward cardiorespiratory fitness

Trying to maintain overall health

• n A
• sound physical fitness program is fun

• n An
• individual’s fitness program should focus on what they enjoy.

• q Outdoor
• activities

• q Social
• recreation

• n A sound physical fitness program includes variety and
• consistency

• n A variety of activities helps to maintain interest and
• increase enjoyment

• n The Physical Activity Pyramid highlights the
• variety of activities that constitute a fitness program

• n A sound physical fitness program appropriately
• overloads the body

• n Hypertrophy:
• gain in muscle strength and size from repeated work that overloads the muscle

n Overload principle: additional physical demands on the body to improve fitness

q Excess exertion is NOT recommended

• q FIT principle
• determines appropriate overload

• n The
• FIT Principle

• q Frequency
• – the frequency of physical activity varies with fitness goals

• q Intensity
• – determining proper intensity may be based on maximal heart rate or Borg Scale
• of Perceived Exertion

• q Time
• of activity – total activity time is an accumulation of activities or
• completed all at once

• n A
• sound physical fitness program includes a warm-up and a cool-down period

• q Includes
• stretching and calisthenics

• q Warm-up
• increases blood flow and body temperature, and prepares a person
• psychologically for the activity

• q Cool-down
• helps to prevent injuries and may reduce muscle soreness

• n Adenosine
• triphosphate (ATP) – the energy carrying molecule in the body

• n ATP
• must be generated continuously since muscles store only enough ATP for 1–3
• seconds of activity

Fuel for Physical Activity

• n After
• depleting ATP stores, muscles turn to other sources:

• q Creatine
• phosphate (CR) stores some energy that can be used to make ATP

• q Creatine
• phosphate stores enough energy for 3 to 15 seconds of maximal physical effort

• n After
• creatine phosphate, glucose is the next source of energy for ATP
• production

• n
• Glucose provides ATP through glycolysis

• n
• The most common source of glucose during
• exercise: muscle glycogen and blood glucose

• n Glycogen
• stores are limited

• n
• Primary end product of glycolysis is pyruvate

• n With
• limited oxygen, pyruvate is converted to lactic acid, by-product of
• intense activity

• n Excess
• lactic acid goes back to the liver to be converted back into glucose

• n Glucose
• metabolism

• q Anaerobic
• breakdown of glucose yields 2 ATP molecules

• q Aerobic
• breakdown of glucose yields 36 – 38 molecules of ATP

• n Triglycerides
• (fats) can be metabolized to generate ATP

• q For
• low intensity exercise

• q For
• exercise of long duration

• q Abundant
• energy source, even in lean people

• q 2x
• more energy per gram as carbohydrate

• n Carbohydrates
• and fats can both be used as energy sources for ATP production

• q Carbohydrates
• are mostly used for high intensity activity

• q Fats
• are used for low intensity exercise

• n Proteins
• (amino acids) are not used as a fuel source for exercise

• n Energy
• needs

• q Energy
• needs may be higher for athletes

• q Different
• energy needs for males and females

• q Depends
• on body size

• q Depends
• on the type of physical activity

• n Recommended
• diet includes

• q 45-65%
• of kcal from carbohydrates

• q Following
• exercise: consume carbs with protein enhances muscle protein synthesis

• q Critical
• period (3-4 hours after exercise): to optimize glycogen storage and muscle
• protein synthesis

• q Carbohydrate
• loading: alter exercise duration and carb intake to maximize muscle
• glycogen

• n Recommended
• diet includes

• q 15-25%
• kcal fat (less than10% saturated fat)

• q 12-20%
• kcal from protein

• § For
• most: 0.8 g/kg weight

• § For
• athletes: slightly more

• § Most
• Americans already eat 2x protein needs

• § Studies
• do not support a high protein diet

• n High
• protein, low carbohydrate diet marketed for athletes is NOT recommended

• q Too
• low in carbohydrate and energy to store glycogen, support training and
• performance

• n Functions
• of Water

• q Temperature
• regulation: evaporative cooling

• q Transport
• nutrients, hormones, waste products

• q Component
• of chemical reactions

• q Part
• of body tissues

q Lubricant

• n Maintaining
• water balance is critical

• q Drink
• fluids before, during, and after exercise

• q Drink
• enough water to maintain body weight

• q Training
• in hot environments requires careful attention to water intake

• q Heat
• illnesses commonly experienced during physical activity: heat syncope, heat
• cramps, heat exhaustion, and heatstroke

• n The requirements for some vitamins and minerals may be
• altered in athletes

q B vitamins

q Calcium

q Iron

n Most of these nutrients can be met with a healthy diet

• n Iron supplementation may be required under proper
• medical supervision

• n Ergonomic
• aids: substances used to improve exercise and athletic performance

• q Many
• of these products are not effective

• q Some
• of these products are dangerous

• q Reliable
• research and accurate information on these products is hard to find

• n Ergonomic
• aids: substances used to improve exercise and athletic performance

• q Many
• of these products are not effective

• q Some
• of these products are dangerous

• q Reliable
• research and accurate information on these products is hard to find

Ergonomic Aids

• n Ergonomic
• aids used to increase muscles and strength include

• q Anabolic
• steroids

• q DHEA
• (dehydroepiandrosterone)

• q GHB
• (gamma-hydroxybutyric acid)

q Creatine

• n Ergonomic
• aids used to increase energy levels and optimize fuel use include

q Caffeine

q Ephedrine

q Carnitine

q Chromium

q Ribose