Obesity and Weight Management

BMI for Obese

>30

BMI for Overweight

>25

BMI for Normal

18.5-24.9

BMI for Underweight

<18.5

Define Obesity

disease defined by excess adipose tissue that is associated with adverse impacts to QOL of physical health

What percentage of US adults are overweight/obese

74%, 40% obese

What percentage of US adults meet aerobic activity guidelines

only 50%

What is the main factor contributing to rising obesity rates

Changes in lifestyle with modern society to eat more and exercise less

How does excess body fat affect children?

-55% chance of becoming an obese adult

-exhibit higher risk of preventable illnesses as adults

What are problems linked to excess body fat

-HTN

-Coronary artery disease

-CVA

-high blood sugar/diabetes

-cancer

-dyslipidemia

-increased joint loads

-gallbladder disease

How does having healthy levels of body fat affect a person?

-reduce risk of mental decline and impaired cognition

-improves insulin sensitivity and blood lipid profile

-delays/prevents diabetes

Around what BMI does mortality risk increase?

around 30

What is excess body fat caused by

genetic and environmental/societal factors

Define hunger

physiological response to nutritional need

Define appetite

psychological response

What percentage of risk of obesity is attributed to genetic factors

40-70%

Genetic makeup may NOT ____ obesity, but ____ the threshold for its development

directly cause, lower

Genetic influence examples

-food intake and cognitive restraint

-adipocyte formation/storage

-preference for exercise activity

-varied thermogenesis based on caloric intake

Describe Leptin

-hormone that blunts appetite and promotes satiety

-released from adipose tissue

-acts on hypothalamus

More adipose = ?

more leptin

What does high leptin correlate with

-high levels of glucose

-HTN

-high cholesterol

-decreased sensitivity to leptin

What happens with a defective leptin gene?

-decrease sensitivity to leptin

-faulty leptin production = too little, never full

Describe the UCP2 gene

-regulated mitochondrial metabolite transport

-contributes to resting metabolic rate

What is futile metabolism?

-related to UCP2 gene

-burn extra calories to increase heat

What happens with a defective UCP2 gene?

-decreased futile metabolism

-increased storage of calories

What is Set Point Theory and the main criticism?

-each person has a predetermined weight

-physical activity can reverse the effects

Describe Obesogenic environment

-components of individuals' physical, political, economic, and sociocultural circumstances

-health disparities and stigma

Excess weight can often parallels ____ rather than ____

reduced PA, increased caloric intake

What is chronic energy imbalance

-modern society makes it easy to be inactive

-small progressive increases in BW

Avg weight gained per year

2-3 lbs

Avg excess cals per day

20-30 cals

How can weight stigma negatively impact someone?

-trigger obesogenic process

-stress hormones, physiological and behavioral changes linked to poor metabolic health and increased weight gain

-60% increased risk of mortality

How can we promote health and not weight stigma?

-treat as a disease not personal failing

-push to improve overall health rather than just lose weight

Weight biases in healthcare

-prevalent both implicitly and explicitly

-need person centered, empathetic language

-even brief convo can lead to lost weight

At any weight, those with low ____ are at higher risk than those with high ____

cardiorespiratory fitness, fitness

Describe Fit but Fat

-obese population who exercises >150 min/week of mod intensity activity

-1/2 death rate and lower rates of CVD than unfit "normal" weight population

Describe Healthy at Every Size

-weight is not an adequate indicator of health in isolation

-focus on adopting healthy lifestyle habits

-engage in intuitive eating model

-find movement that brings joy

What are INDIRECT ways to measure weight?

-BMI

-height/weight

-wasit/neck circumference

Components of Body Compoistion

-water

-protein

-bone mineral

-body fat

Where is fat deposited?

-subcutaneous

-inter/intramuscular

-abdominal/thoracic cavity

What is Essential fat?

-bone marrow

-organs

-nervous system

-muscles

Male and Female essential fat %

-Male = 3%

-Female = 12%

Where is fat stored?

-pads organs

-insulation

-energy source

-white adipocytes

What body fat distribution is most common for males vs females

-Males = android/apple

-Females = gynoid/pear

Which body fat distribution is worse?

Android increases risk fo CVD and metabolic syndrome

What type of fat is more metabolically active

Abdominal visceral fat

What are important measures for health risk

-Waist circumference

-Waist to hip ratio

What is the PREFERRED method to determine body comp?

Measure percentage body fat (%BF)

What is the average %BF of males and females

What defines obesity using %BF

What must be considered about %BF

-much less studied than BMI

-more variability of normal range

-low reliability measuring tools

What is the clinically significant threshold for weight loss vs target of successful WL trial

-~3% weight loss

-5-10% weight loss

Why must energy intake < energy expended for weight loss

-creates negative energy balance

-energy cannot be created or destroyed

-any positive energy balance from food must be stored in body

How do you calculate Total Energy Expenditure (TEE)

(Basal Metabolic Rate/Resting Energy Expenditure) + (Physical activity/Exercise Energy Expenditure) + Thermic Effect of Food

1 MET = ___ mL O2/kg/min

3

What are the three ways to achieve a negative energy balance

-reduce energy intake

-increase energy expenditure

-do both

What is the overall recommendation to achieve a negative energy balance

-weight loss of 1-2 lbs/week

-500-1000 kcal deficit/day

What are inappropriate methods of weight loss

-restricting or promoting specific foods

-various methods of body water loss

-OTC pills and solutions

What is the recommended reduced caloric intake per day

500-1000 kcal/day

What are the three broad approaches for reduction/restriction

-Dietary = what to/not eat

-Time = when to/not eat

-Calories = how much to eat

Macronutrient recommendations

-CHO = 45-70%

-Fat = 10-35%

-Protein = 10-35%

Describe low carbohydrate diet

-ignore total kcal and cholesterol/sat fat content

-50-100g CHO per day

-<30g for keto

-initial water weight loss but extra solute load on kidneys

What do very low carb diets do

increase ketones from fatty acid and lower appetite

What do high CHO diet do

-increase blood glucose

-trigger insulin release

-promote fat storage/inhibit fat release

Potential negatives of Low CHO diets

-raises serum uric acid = kidney stress from solutes

-altered electrolyte concentration = cardiac arrhythmias

-depletes glycogen reserves = fatigued

-decrease Ca2+ balance = bone loss

-dehydration

-impair fetal development

-elevate cholesterol

-low in fiber

What is early weight loss mostly

-water

-~70% in first week

How does hydration level affect fat loss

-it does not

-lose same amount of fat regardless of fluid intake level

What does a longer term deficit promote?

-fat loss

-after 8 weeks, fat loss >2x vs first week

Describe low fat diets

-mediterranean or ornish

-70-20-10 ratio of CHO, protein, fat

Disadvantage of low fat diet

-low fat foods highly processed

-too low in fat = interfere with absorption of vitamins and limit intake of essential fatty acids

Describe high protein diet

-paleo

-emphasize fish, lean meats, fruit, non-starchy veggies

-naturally low in fat

-increase satiety

-increase TEF b/c of digestion of protein

Disadvantages and problems with high protein diet

-hard to adhere

-strain on liver and kidney function, accompanying dehydration

-electrolyte imbalance

-glycogen depletion

-lean tissue loss

Describe semi-starvation/very low calories diets

-used in morbid or grade 2 obesity

-used as last resort

-usually specialized powdered food rich in protein: 500-800 kcal/day

-breaks habits

-promotes rapid weight loss

-report not being hungry because of mild ketotic state

Disadvantages of semi-starvation

-ketones cause bad breath

-cardiac arrhythmic deaths caused this to be considered dangerous

-dehydration and gallstones

-difficult to maintain weight loss

Describe intermittent fasting

-time restriction eating

-alternate day fasting

-5:2 feast and fast days

-demonstrated safety

-improved glycemic control

-improved BP

-fat loss

-improved lipid profile

-maintain lean body mass

What is the main reason intermittent fasting works

reduces total energy intake

What is the satiety index

-isocaloric measure of fullness

-more fat negatively correlated with SI

What is weight loss independent of?

macronutrient composition of diet

What does long term weight loss occur with

reduction in energy

What is the recommendation to increase energy expenditure

250-500 kcal/day

Equation for calories burned per minute

[METs 3.5 Body weight (kg)]/200

What is best for sustained weight loss

diet and exercise is better than just diet alone

What does exercise prevent the loss of during caloric restriction

prevents loss of lean muscle mass

What is the effectiveness of PA for weight loss associated with

amount of excess body fat

____ EE due to PA >/< ____ calories due to increased hunger

increased, >, increased

What are benefits of physical activity

-buffer for additional caloric intake

-psychological benefits

-more sustainable

What are examples of lifestyle changes

-perceived barriers to PA and healthy eating

-dietary counseling

-Physical therapy

Examples of perceived barriers

-no reason for being sedentary other than health problems

-lack of social support

-lack of knowledge

-lack of access to facilities

What are the effects of dietary counseling

-moderate, yet significant effect

-motivational interviewing

-increasing self-efficacy

What is a key part of long term weight loss success

exercise

Weight loss chances of success ____ related to level of obesity

inversely

Reasons why exercise/PA is important for weight management

-consistent factor for sustained weight loss

-offsets loss of fat free mass during energy restriction

-lowers disease risk of regardless of weight

-attenuates tendency to gain weight throughout life

-flexibility for energy deficit