Lecture 9: Weight Management Flashcards Preview

Nutitional Science > Lecture 9: Weight Management > Flashcards

Flashcards in Lecture 9: Weight Management Deck (34):

Energy Out: Basal Metabolic Rate

-Energy required to maintain functions of the body while at rest (after 12 hr fast & rest)
-Involuntary activities: respiration, circulation, synthesize new cells & hormones, sending nerve signals, fluid balance, body temperature
-BMR accounts for about 60-70% of TEE


Energy Out: Basal Metabolic Rate (Determinants)

- Lean Body Mass (age, gender)
*Obese usually have higher LBM and burn more Calories/d
- Height (LBM and body surface)
- Age: decrease BMR 3-5%/10 yrs after age 30 (LBW and hormone changese
- thyroid hormone: (incease BMR)
-starving/fasting: (decrease BMR)
-Growth: want your BMR to increase
-Healing/fever (7% increase BMR)


Can you change your BMR?

-Increase: building or maintain LBM – physical activity, >1.05g/kg protein intake* (research still conducted)
-Decrease: energy restricted diets, lower lean body mass


Energy Out: Physical Activity/Exercise

-Most variable of outputs
-Accounts for ~15-35% of TEE
*Couch potato: ~ 10%
*Athlete in training ~ 50%
Dual effect on output
↑ Energy expenditure during and after exercise
↑ LBM= ↑ BMR

-Energy costs of various activities (table 13.2)
*Higher intensity= more Calories burned per minute
*Stretching vs running at 8.6 mph


Energy Out: Thermic Effect of Food

-Energy used in food digestion, absorption, transport metabolize, and storage of nutrients
-TEF accounts for ~5-10% of the energy consumed & TEE
*Consume 500 Kcals = 25-50 Kcals needed for TEF
-Perhaps more energy needed metabolize protein and carbohydrate than fat
*Meta-analysis found higher protein (25-35% Calories), low-fat diet had more weight loss (~2lbs) than lower protein (12-18%), low-fat diet with similar Caloric intake*
*AMDR for protein: 10-35%


Alternative Means to “Speed Up Your Metabolism”

*may preserve LBM: > 1.05 g/kg/d
*Increase thermogenesis
*Increase BMR but has not shown to reduce body weight
*Increase blood pressure, irregular heartbeat, sleep disturbance
-Capsaicin in chili peppers (cayenne pepper)
-Cold water: REE increases 25-30% for 30-40 min


Fed & Overfed State

-Glucose for energy, maintain blood glucose levels, then glycogen formation
*Remaining glucose converted to FA for energy storage
-Amino acids used for body protein needs
*Excess converted to FA for energy storage
-FA used for fuel
*Excess stored  excess body weight


Short-Term Fast (0-6 hrs)

-0-6 hr fast (between meals & overnight)
1. Liver glycogen to maintain blood glucose levels and for energy
2. Gluconeogenesis to maintain blood glucose levels and glucose for brain
3. FA for energy


3-5 Day Fast

-3-5 d fast (no glycogen left)
1. Gluconeogenesis- fast rate of protein breakdown (and glycerol) for maintaining blood glucose levels
2. FA & Ketones


5-7 Day Fast

-5-7 d fast
*Metabolic rate slows and energy needs declines
*Gluconeogenesis slows down
1. Ketones & FA- nervous system adapts to use ketones, spares protein.
2 . Gluconeogensis from protein (to keep the TCA cycle working & maintain BG levels & for RBC)


Estimating Energy Requirements

Macronutrients + O2 --> ATP + CO2+ H2O and heat

-Direct calorimetry
-Indirect calorimetry
-Record intake over 3-7 days and use average
-Rough estimate
-Predictive equations


DRI: Estimated Energy Requirement (EER)

-Average dietary energy intake (kcal) to maintain energy balance in a healthy adult
-Individualized: age, gender, weight, height, level of physical activity
-Modified if healing, disease or pregnancy


A Healthy Body Weight

-Body weight: bone, muscle, fat, tissue, fluid*, blood etc.

-What is a healthy body weight?
*A weight appropriate for your age, physical development
*A weight that someone can realistically achieve without disordered eating & exercise patterns & is acceptable to the individual
*A weight where your nutrient needs can be met
*A weight associated with reduced disease risk
~Overweight & obesity are associated with DM, HTN, heart disease, stroke, gallbladder dz., osteoarthritis, sleep apnea, cancers (endometrium, breast, prostate, colon)
*Adequate lean and fat tissues


Estimation of Healthy Weight

For men:
106 pounds for the first 5 feet
add 6 pounds per each inch over five feet
A man who is 5’10” should weigh 166 lbs. (149-183 lbs)*

For women:
100 pounds for the first 5 feet
add 5 pounds per each inch over five feet
A women who is 5’10” should weigh 150 lbs. (135-165 lbs)*
*+/- 10% for frame size

110-120%: overweight
>130%: obese


Assessing Body Weight: Body Mass Index

Body mass index (BMI)= weight (kg)/height (m)2
BMI = [weight (lbs) / height (inches)2] x 703

Underweight: <18.5
Normal: 18.5-24.9
Overweight: 25-29.9
Obese: 30 or greater
Morbid Obesity: 40 or greater


Assessing Body Weight: Body Mass Index (disease and limitation)

Disease risk increases when BMI 25, especially >30

-Fat distribution
-Doesn’t take muscle mass and bone size into account
-Not as useful in people >65
-Ethnic variation (higher risk of disease at lower -BMI and waist circumferene cut-offs)


Body Composition: Assessing LBM vs Fat Mass

Methods are estimates:
-Fat folds (skin folds)
-Underwater weighing
-Bioelectrical impedance
-Dual-energy x-ray absorptiometry (DEXA)
-Bod Pod


Body Fat Distribution

Abdominal fat increase chronic disease risk

-Waist-to-hip ratio
*Men > 0.90
*Women > 0.80

-Waist circumference
*Men above 40 in. (or 102 cm.)
*Woman above 35 in. (or 88 cm.)


Concerns of Being Overweight/Obese

Overweight & obesity are associated with:
-Metabolic Syndrome
-Type 2 Diabetes Mellitus*
-Heart disease & stroke*
-Cancers* (endometrium, breast, prostate, colon)
-Gallbladder dz.
-Sleep apnea
*In the top 10 leading causes of death


Metabolic Syndrome

Must have 3 of these 5 criteria:

-Waist circumference
*Male > 40 in.
*Female > 35 in.
-TG > 150 mg/dL
-HDL-C: male < 40 and female < 50 mg/dL
-Blood Pressure > 130/85 mmHg
-Fasting Blood Glucose > 100 mg/dL


Fitness vs Fatness

-Overweight with the absence of risk factors
-Health at Every Size
*Self-acceptance: human beauty regardless of weight
*Physical activity: enjoyment & quality of life
*Normalized eating: peaceful relationship with food, relearn to eat in response to hunger and fullness cues.
-Remaining concerns: osteoarthritis, cancers, gallstones, erectile dysfunction, sleep apnea


Why Are So Many People Overweight?

-Last 2 decades
*Overweight children doubled
*Overweight adolescents tripled
-Calories in vs out but is this harder than it seems?
*Genetics (Nature)
*Environment (Nurture)

-69.2% of Adult Americans are overweight or obese
-36% are obese
-18% children 6-19 are obese


Hormone: Leptin

release site: Fat (obese produce more but are not sensitive to signaling)

-decreases feeding


Hormone: Insulin

Release site: Pancreas

- decreases feeding


Hormone: CCK

Release site: Gut

- decreases feeding


Hormone: PYY

Release site: Gut (obese has less)

- decreases feeding


Hormone: NPY

Release site: Hypothalamus

- encourage intake of food


Hormone: Ghrelin

Release site: Gut (Obese are sensitive)

- encourage intake of food


Genetics (Nature)

Thrifty metabolism theory
-Gene to conserve energy- expend less energy
-Useful when starvation was a problem
Set-point theory
-Body will try to maintain a set body weight
-In times of ↑ energy intake = ↑ BMR (↑ TEF, fidgeting)
-In time of ↓ energy intake = ↓ BMR


Environment (Nurture)

-Overeating – excess Calories
-Physical inactivity
-Overeating Reasons:
*Learned eating habits from family, friends, time of day
*Availability of high Calorie, low nutrient foods
*Perception that healthy food is expensive
*High Caloric foods taste good
*Fewer family meals
*Eating more meals outside the home
*Increase servings, increase fat, Calories, salt, decrease fruits and vegetables
-Physical inactivity
*Work long hours
*Video games
*Everything is automated
*Lack of sidewalks
*Lack of playgrounds


Nature vs. Nurture

-Genetic predisposition does not control one’s destiny
-Those at risk for obesity must be ever-vigilant
-Increased physical activity and moderate food intake can promote a healthy weight


Approaches to Weight Loss: Eating Less

-Eat within your Caloric needs: choosemyplate.gov
-Choose lower energy density foods- next slide
-Read food labels & Calorie menu boards
*Should the government require labeling & banning toys?
-More fiber- whole-grains, fruits & vegetables (foods that weigh more w/high water content)
-Consume adequate water
-Balanced macronutrient intake
*Perhaps small protein at each meal as long as within Caloric needs (satiety, FFM, TEF)
-Minimize empty calories: SOFAS
-Eat smaller portions- salad plate
-Split restaurant meals
-Regular mealtime prevents overeating at next meal
*Student question: what will happen if one doesn’t eat breakfast?
*Breakfast eaters had a greater reduction in impulsive snacking and ate less at later meals. (recent 2013 study did not confirm)
*Skipping breakfast is associated with a higher BMI and increased obesity risk, despite lower reported daily energy intakes. (some epidemiological studies)
-Portion out your servings- don’t eat out of a bag
-Eat slowly to allow hormones to signal feelings of fullness
*Wait 20-30 minutes before you have seconds
*Make your second serving just vegetables
-Think before you eat- mindful eating
*Am I hungry or bored?
*Be aware while you eat : smell, taste, texture, feeling
*Assess fullness during your meals: eat until you have had enough, not until you are full


Approaches to Weight Loss: Being Physically Active

-Prioritize your health
-Find activities you love
-Keep it simple: 3, 10 min segments; 20 min walk
-Find a friend
-Add it to daily activities
*Park further
*Take stairs
*Walk or ride bike to school/work


Approaches to Weight Loss: Setting Reasonable Goals

-Reduce wt by 5-10%
-1-2 lbs/week
-Decrease energy intake ~250-300 kcal/day
Small changes make big differences!
Goal is for life-long changes