What are the 3 main tools for diagnosing overweight/obesity
- BMI
- Waist circumference
- Edmonton Obesity Stages System
BMI
- calculate
- levels and classes
- As a measurement: is it preferred? what populations do we use it/not use it on?
weight (kg) / height (m^2)
or
weight (Ibs) x 703 / height (inches^2)
<18.5 underweight; class 0 18.5-24.9 normal; class 0 25-29.9 overweight; class 0 30-34.9 obese; class I 35-39.9 obese; class II >40 obese; class III
- BMI is the preferred measure of adiposity
- still need other health measures
- used for most adults 18-65, excluding: those with high muscle mass (body builders, long distance athletes); those with lower muscle mass (children) or those losing muscle mass (elderly); and pregnant/lactating people
BMI clinical applications (5)
BMI limitations (1) and misinterpretations (3)
- screens for overweight/obesity (and health risks)
- predicts future morbidity and death
- track changes in weight
- refer patients who may benefit from obesity management specialists
- categorize cardio-metabolic risk of patients
- measures weight only, not body composition (fat vs muscle vs bone)
Misinterpretations:
- older adults have more fat with same BMI as younger ppl
- women have more fat with same BMI as men
- muscular people have higher BMI because of high muscle mass
Pediatric obesity classification
- what age can BMI be used?
- how do we track pediatric BMI?
- classification of obesity in children?
- children over 2 years (to see if they are at risk for obesity and overweight)
- use BMI-for-age growth chart
- overweight: 85th percentile =< BMI-for-age <97th percentile
- obese: 97th percentile =< BMI-for-age <99.9th percentile
- severe obesity: BMI-for-age >= 99.9th percentile
prevalence of obesity in Canada
increasing every year
** obese classes II and III are increasing at disproportionate levels
Adult waist circumference
- what should it be (in 3 categories?)
- how to measure?
Canada, USA
Women: >=88cm
Men: >=104cm
caucasian/europoid, middle eastern, mediterranean, sub-saharan African:
Women: >=80cm
Men: >=94cm
Asian, central and south american
Women: >=80cm
Men: >=90cm
–> measuring tape just above ASIS; tighten around waist without depressing skin; recommended to use calibrator
Adult waist circumference clinical implications
- distribution of body fat is an indicator of health risk
- abdominal fat is most biologically active (releasing cytokines, inflammation, and insulin resistance)
- high waist circumference is associated with a high risk for CVD and T2D
- measuring waist circumference can screen for people who have normal BMI, but more abdominal fat (different fat distribution, normal BMI - high risk for obesity related illness and death)
Edmonton Obesity Staging System (EOSS)
- what is it for?
- staging system designed to complement BMI, to describe severity of obesity
- independent of BMI; for those who are already obese
- to describe morbidity and functional limitations associated with excess weight (5 graded categories, 0-4)
- independently predicts mortality associated with obesity, independent of BMI
Edmonton Obesity Staging System
- describe each stage
Stage 0
- No: physical, psychological, functional, or obesity related risk-factors
Stage 1
- patient has subclinical obesity related risk-factors (borderline hypertension, elevated liver enzymes, impaired fasting glucose)
OR
- mild physical symptoms (joint pain, dyspnea on moderate exertion, fatigue) - not requiring medical treatment
OR
- mild obesity related psychological symptoms or impairment of well-being (QoL not affected)
**stages 0 and 1, no admission, refer to primary care for prevention methods
Stage 2
- patient has established obesity related co-morbidities requiring medical intervention (hypertension, diabetes, sleep apnea, PCOS, osteoarthritis, reflux disease)
OR
- moderate obesity related psychological symptoms (depression, eating disorders, anxiety disorders)
OR
- moderate functional limitations in everyday life (quality of life beginning to be impacted)
Stage 3
- patient has significant obesity related end-organ damage (MI, diabetic complications, heart failure, debilitating osteoarthritis)
OR
- Significant obesity related psychological symptoms (major depression, suicidal)
OR
- Significant functional limitations in everyday life (unable to work or complete routine activities, reduced mobility)
OR
- Significant impairment of well-being (quality of life severely impacted)
Stage 4
- Severe obesity-related comorbidities (possibly end-stage)
OR
- Severely disabling psychological symptoms
OR
- Severe functional limitations
What stage and class is this? - physically active female, BMI 32 kg/m2, no risk factors, no physical symptoms, no self-esteem issues, and no functional limitations
Class I; Stage 0
What stage and class is this? - 49 year old female with a BMI of 67kg/m2, diagnosed with sleep apnea, CV disease, GERD, and suffered from stroke, Patient's mobility is significantly limited due to osteoarthritis and gout
Class III; Stage 3
What stage and class is this? - 32 year old male with BMI of 36kg/m2, with primary hypertension and obstructive sleep apnea
Class II; Stage 2
What stage and class is this? - 38 yo female with BMI of 59.2kg/m2, borderline hypertension, mild lower back pain, and knee pain. Patient does not require any medical intervention
Class III; Stage 1
What stage and class is this? - 45 yo female with BMI of 54 kg/m2, who is in a wheelchair, because of disabling arthritis, severe hyperpnea, and anxiety disorder
Class III; Stage 4
EOSS clinical limitations
- clinicians may disagree whether it’s obesity that caused the medical conditions
- uses definitions of risk/comorbidities that may change with new research
- subjective parameters to stage psychological factors
- doesn’t capture weight related issues that occur at lower BMIs
- doesn’t contain a measure for readiness to change
- EOSS-P (pediatrics), is currently undergoing validation
Complications of Obesity (list)
- list common (don’t need to memorize)
psychological:
- low self-esteem
- depression
- eating disorders
- social isolation
pulmonary
- exercise intolerance
- obstructive sleep apnea
- asthma
GI
- GERD
- gallstones
- fatty liver disorder
Renal: glomerulosclerosis
MSK:
- arthritis
- pain
- flat feet
- multiple injuries (ankle sprains, forearm fractures)
CVD:
- heart disease/failure
- hypertension
- dyslipidemia
- endothelial dysfunction
- chronic inflammation
Endocrine: - metabolic disorder - Type 2 diabetes - menstrual irregularities - PCOS -
Causes of Obesity
- ultimately energy imbalance consumed > expended
- complex and multifactorial
- factors that influence obesity (environment, overconsumption of calories, physical inactivity, genes, health conditions, inadequate sleep patterns, medications, psychosocial)
3 levels of obesity management
- surgery (for more severe)
- pharmacotherapy (for more severe)
- lifestyle changes (diet and exercise) - first line of treatment
* *lifestyle modifications must be present throughout all levels of obesity treatment
Obesity etiology:
- what causes positive energy balance? (3)
- what factors influence each of the 3 causes
- imbalance of diet, metabolism, or activity
- many factors can influence dietary consumption, metabolism, and activity level
diet and activity level:
- sociocultural
- biomedical
- mental
- medication
metabolism:
- age
- gender
- genetics
- hormones
- skeletal muscle
- medication
Etiological Framework for assessment and management of obesity (4 steps):
STEP ONE: Assess energy requirements and metabolism
- Total Energy Expenditure (TEE) = Resting energy expenditure (REE) x Activity Factor (AF) x Stress Factors (SF)
STEP TWO: Assess determinants of obesity
- increased caloric intake? slow metabolism? reduced activity?
- 4Ms: framework for assessment of overweight and obese patients (mental, mechanical, metabolic, monetary)
- identify primary areas of issues related to obesity causes (socioeconomic, mental, physical)
- -> Mental: knowledge, information, mood, self-image, sleep
- -> Mechanical: pain, osteoarthritis, reflux, apnea, thrombosis,
- -> Metabolic: insulin resistance, PCOs, menstruation issues, type 2 diabetes, metabolic syndrome, dyslipidemia, gout, cancer, infertility
- -> Monetary: education, employment, low income, disability, surgery, weight-loss programs,
- the 4 Ms also help with EOSS staging
STEP THREE: Develop management plan
- must address underlying cause with accompanying supports
- -> patient who is self-medicating with food, identification and treatment of depression is first step of reducing food intake
- -> patient with socioeconomic barriers to healthy eating/physical activity, refer to social worker
- -> identification of obstructive sleep apnoea will be key to increasing physical activity
- -> psychological counselling to manage alcohol and substance abuse or trauma, or eating disorders, can put patients on the path to weight maintenance
Barriers to lifestyle and behavioural modifications
- patient perceived
- physician perceived barriers
- how do you define success
Patient: emotional and social barriers (stress, depression, loss of motivation); food cravings and hunger; unsupportive environment; social pressures; lack of time, feeling tired; knowledge and skills; unrealistic expectations
Physician: lack of time to discuss; lack of patient readiness; inadequate knowledge of food, diet, and medical management of obesity; reluctance to address fatness in patients - “willpower” thing instead of serious health concern
Success: patient-perceived: - increased energy - increased sleep quality - increased self esteem - increased meals made at home - stairs instead of elevator
physician-perceived:
- decreased rate of weight gain, stabilization, or loss
- decreased waist circumference
- improved biochemical markers
- increased fitness ability
Prevention and Management of obesity: Canadian Clinical Practice Guidelines 2006
Step 1: lifestyle modifications
satisfactory?
Step 2:
Yes –> regular monitoring, weight maintenance
- maintain healthy eating and exercise
- address other risk factors: monitor weight, BMI, waist circumference every 1-2 years
No –> pharmacotherapy
- BMI >27 plus risk factors or BMI >30
- if haven’t lost 1 pound per week, 3-6 months after intervention
No –> bariatric surgery
- BMI >35 plus risk factors or BMI >40
Five As of managing obesity
Ask: - for permission to discuss weight Assess: - BMI in adults; percentile in children - Stage obesity - Figure out driving causes Advise: - obesity risks - benefits of moderate weight loss - discuss treatment options Agree: - agree on weight loss expectations (SMART goals) - Specific, Measurable, Attainable, Realistic, Time-bound Assist: - in addressing barriers to weight loss, accessing resources, etc. - **Arrange for follow-up!!!
Five As for physical activity
Ask:
- determine PAV (physical activity vital sign): minutes/day x days/week (goal of 150 minutes)
- how many days/week do you engage in physical activity?
- how many minutes?
Advise:
- tell patients about the guidelines (150 per week)
- add muscle or bone strengthening activities (2 days/week)
- tell patients of health benefits of exercise (reduce risk 25-50% of chronic diseases)
Assess:
- model of change (pre-contemplation, contemplation (intend to change in next 6 months), preparation (intend to change in immediate future), action (specific action in past 6 months), maintenance (made changes, working to prevent relapse), relapse)
Arrange:
- follow-up!
