2PF3A - Obesity

in 2004 - approximately what percentage of Canadian children/youth surveyed were overweight/obese

What was that percentage in 2015?

2004 - 25%

2015 - 30%

true or false: data from Canadian Health Measures Survey indicates rate of overweight/obesity in children and youth aged 5-18 remained stable from 2011-2015

true

true or false: many obese children/adolescents do not outgrow this condition

true - obese children aged 10-13 have 80% chance of becoming obese adults

many more children who were not overweight children will gain excess weight in adulthood

trends in weight gain suggest that _____ of normal weight 20-year-olds will become overweight in the next 8 years and approx ______ of overweight 20 year olds will become obese in the next 8 years

1/3

by 2040 we can expect _______% of 40 year olds in Canada will be overweight or obese

70

overweight and obesity in adults is measured using what?

BMI - a person's weight (in kg) divided by sq of their height in m^2

What is the ideal adult BMI? What defines overweight? What defines obese?

ideal - between 18.5-24.9

overweight - 25-30

obese - over 30

because children grow at different rates based on age and vary in growth patterns by gender, ideal weight for children is based on what?

growth charts

plotting a child's BMI on a growth chart appropriate for their age/gender allows you to see what percentile they fall within

The dieticians of Canada, Canadian Pediatric Society, College of Family Physicians, Community Health Nurses of Canada recommend the adoption of this growth chart as the gold standard for assessing growth in Canadian children

WHO growth charts5

thought to more accurately reflect growth of Canadian children and were created based on populations in a number of different countries

the cutoffs for the WHO growth charts are broken into 3 categories for children - what are they?

1. birth-2

2. 2-5

3. 5-19

in the 5-19 year category on the WHO growth chart, overweight is assessed as BMI-for-age above this percentile, specific for gender

85th

in the 5-19 year category on the WHO growth chart, obese is assessed as BMI-for-age above this percentile, specific for gender

97th

in the 5-19 year category on the WHO growth chart, severe obesity is assessed as BMI-for-age above this percentile, specific for gender

99.9th

In Canada, this age group is most affect by being overweight or obese

adolescents

from 1978-2004 the proportion of overweight children between 2-5 remained the same although obesity (previously unseen in this group) rose to 6% in 2004

data for which age group were not reported in the Canadian Health Measures survey of 2009/2011 or the Canadian Community Health Survey of 2015

2-5 years old

overweight/obesity rates in the 6/11 age group were increased by what factor compared to results in 1978/1979

in 2004

in 2011

2004 - doubled from 1978/79

2011 - tripled from 1978/79

true or false: obesity in the 6-11 age group has remained fairly stable from 2011-2015

true

the prevalence of obesity in the 12-17 age group has ____________ steadily from 1978-1979 while the prevalence of overweight individuals has remained stable from 2004-2015 at around 20%

increased

what are some of the risk factors identified with obesity by the Canadian Community Health Survey

1. more than 2 hrs screen time per day

2. consumption of less than 5 servings of fruits/vegetables per day

this is caused by an imbalance between energy in (intake of nutrient dense foods) and energy out (activity level)

obesity

Why is obesity not a simple problem?

many variables which dictate what the intake/output ratio will look like - there is no single cause and no simple solution

What are some broad factors that can affect obesity in the scope of:

1) work/school/home

2) community/locality

3) national/regional

4) international

1. conditions in family/home, availability of facilities/leisure time

2. public transport, safety, quality of health = community

3. education level (may impact food/nutrition choices regionally or nationally)

4. national perspective on education, healthcare

5. internationally - media and food advertising

Consumption of fast food contributed to what percentage of daily caloric intake in US:

1) children

2) adolescents

3) adults

1. 10%

2. 17%

3. 13%

true or false: in 2004, Canadians consumed less fast food on a daily basis compared to the US

true

on average, fast food consumption in Canada represented ____% of total daily energy intake and was responsible for adding about ________ calories compared to those that did not consume fast food

6.3

206

the highest level of fast food intake in Canadians was observed in which age group/gender?

adolescent males

absolute fast food related caloric intake was ____________ in males compared to females

higher

true or false: fast food intake in Canada is associated with income, education, food security status

false: does not appear to be associated with these factors - but is associated with increased BMI and poorer dietary quality

How can ethnicity cause obesity?

certain populations more susceptible to becoming obese - populations of obese First Nations and Hispanics and Africans higher

adolescent males of ________________ descent and adolescent females of _________________ descent appear to be especially predisposed to development of obesity

Hispanic

African American

How can genetics play into the development of obesity?

biggest predictive factor in childhood obesity is obesity in one or both parents

more strongly correlated with maternal obesity (though genetics are not whole story)

children consume same diet as their parents, have been shown to mirror their activity level

_______________ have the greatest opportunity to make the lifestyle changes necessary to ensure the health of children

parents

but refusal to recognize the problem may lead to continued weight gain over remaining childhood years and maintenance of overweight/obese status into adulthood

besides risk of child's health what else may suffer due to obesity?

quality of life

When Dr. Jeffrey Schwimmer and associates examined quality of life questionnaires for children/adolescents who were healthy/normal weight, obese, and pediatric cancer patients, obese children scores were similar to which group?

pediatric cancer patients

The authors of "The shape of things to come" in the Economist blame what for our increased trend in obesity?

evolution for designing us to store energy for lean times

since we have not experienced lean times our bodies continue to store the excess energy we take in and our waistlines expand

stats from the 2016-2017 Canadian Health Measures Survey indicates that almost ____% of children and youth 5-17 met the target for physical activity at 60 min of moderate-vigourous physical activity as per recommendations

The same survey said that just over half had no more than the recommended ____ hours of screen time per day

40

2

true or false: in 2016-2017, children 5-11 were 2x more likely to meet the screen time recommendation than youth 12-17

true

adipose tissue secretes a number of substances including hormones and inflammatory molecules referred to as what?

adipokines

these allow different tissues in the body to interact to maintain lipid homeostasis

this is the general root cause of many of the health problems associated with obesity

chronic exposure of tissues to high levels of lipids and their sometimes toxic metabolic by products

what is the association between obesity and stroke?

central obesity is the greatest risk - association shown between ischemic stroke and waist-to-hip ratio in both men and women but the risk was greater in men

this is also correcting for confounding factors

shown in all ages but there was a greater risk among those younger than 65

how can obesity lead to type II DM?

due to dysregulated lipid metabolism which then causes insulin resistance

insulin resistance may eventually lead to hyperglycemia when pancreas cannot provide sufficient insulin to affect glucose uptake in cells

what is the association between obesity and vascular disease?

obesity and inactivity are two of the biggest risk factors for development of athersclerosis - can cause CAD and PVD

altered lipid metabolism results from constant excess nutrients as well as diet high in fat leads to lower HDL and higher LDL

inflammatory process (also product of lipid dysregulation) compounds problem by increasing influx of macrophages into vascular tissues where they remove LDL from circulation but create foam cells, further athersclerosis

what is the association between obesity and liver disease?

over nutrition leads to deposit of fat in liver cells - fat deposition further enhanced by insulin resistance

increased risk of fatty liver disease amongst obese individuals and DM patients but is present in everyone who is morbidly obese and diabetic

fatty liver disease may start as asymptomatic but the fat deposits can lead to increased inflammatory activity, fibrosis, sometimes cirrhosis - can cause liver failure and increased chance of hepatocellular carcinoma

what is the association between obesity and colon cancer?

especially central obesity - increases risk of colon cancer

men at higher risk than women - waist circumferences strongly correlated with colon cancer and risk found to increase linearly with increasing waist size in both men and women

visceral adiposity creates even greater risk than elevated BMI alone

what is the association between obesity and osteoarthritis

increased weight adds stress to bones and joints - seen earlier in patients with obesity

adipokines also may have a role in causing and advancing osteoarthritis - also risk in osteoarthritis in non-weight bearing joints such as the hands

inflammatory cytokines like TNF-a promote cartilage breakdown and advance of the disease

true or false: a predisposition to obesity may occur before a child is born

true - if mother is affected by gestational diabetes can have profound effect on child's propensity for weight gain

children born large for gestational age are predisposed to obesity and diabetes, babies born small for gestational age also predisposed to obesity and diabetes

in children born small for their gestational age, the characteristics of obesity and DM may manifest during what stage of their life?

adolescence - when triggered by environmental conditions like inactivity and poor diet

what is the theory behind why children small for their gestational age are more at risk of developing diabetes and obesity?

fetal environment may permanently alter metabolic process so that glucose homeostasis malfunctions during conditions of overabundance of nutrients - puts at risk of insulin resistance, CAD and metabolic syndrome

how can puberty affect obesity?

puberty results in reduced insulin sensitivity and compensatory increase in insulin secretion - this is transient and secretion returns to normal once child has reached full adolescence

true or false: constant excess caloric intake can lead to an increase in the size of adipocytes

true

Why is it a problem to have enlarged adipocytes?

large adipocytes secrete excess adipokines

enlarged adipocytes have little capacity to take in more lipids so the fat may begin to be deposited into the muscle cells

what is the problem associated with excess TNF-a due to obesity?

causes increase in free fatty acids in the bloodstream by causing fat in adipose tissue to break down

TNF-a also inhibits clearance of VLDL (main transporter of triglycerides and some cholesterol in bloodstream)

this adipokine is elevated in obesity and thought to be an important link between obesity, insulin resistance, and the development of DM

this adipokine may play an even larger role in development of atherosclerosis, cardiovascular disease, non-alcoholic fatty liver disease etc.

resistin

leptin normally ________________ appetite and food intake and stimulates energy expenditure

inhibits

true or false: there is leptin resistance in obesity

true: although this is not the key issue of leptin

leptin is also a pro-inflammatory adipokine that promotes production of other pro-inflamm cytokines from immune cells which contributes to overall pro-inflammatory state

describe the positive feedback involving leptin in obesity

leptin is a pro-inflammatory adipokine that stimulates production of pro-inflammatory cytokines like TNF-a and IL-1 which stimulate the production of excess leptin

what is the function of leptin on the hypothalamus?

leptin acts on the hypothalamus and evokes sympathetic activation leading to peripheral vasoconstriction and elevated blood pressure which contributes to hypertension

angiotensinogen is synthesized by adipocytes in direct proportion to what?

their adiposity

recall that angiotensinogen is converted to vasoactive compound angiotensin II by passing through kidneys and lungs

how does angiotensin II elevate bp?

directly promotes vasoconstriction and indirectly increases renal water retention by promoting the release of aldosterone

angiotensin II provides link between increased adiposity/obesity and development of hypertension

this molecule normally produces insulin-sensitizing effects and reduces the production of TNF-a by adipocytes

adiponectin

the effects of adiponectin are _______________ in obesity

reduced

levels of adiponectin decline with increasing adiposity

decreased adiponectin associated with dyslipidemia

how does adiponectin act on lipid metabolism?

adiponectin levels negatively correlated with triglycerides and positively correlated with HDL levels

adiponectin also helps to enhance VLDL clearance

TNF-a is involved in ________________ production of VLDL by the liver and lowering the levels of HDL in circulation in response to increased adiposity

increased

what is the issue with extra circulating triglycerides and free fatty acids?

interferes with insulin signalling in muscle and liver tissue

prevents cells from taking up glucose in response to insulin

Why are the first signs of type II DM elevated triglycerides and impaired glucose tolerance?

increased triglycerides and free fatty acids in the blood stream due to the effects of pro-inflammatory cytokines

the pancreas overproduces insulin to compensate for insulin resistance

these are the first signs of the atherosclerotic process and have been found in children 9 years old

fatty streaks

BMI is _______________ correlated with plasma concentrations of angiotensinogen as well as renin and angiotensin-converting enzyme activity

positively

this is a condition common in obesity, usually caused by insulin resistance - appears as an area of hyperpigmentation usually found in body folds such as back of neck, underarms, groin area

appears as black - area of thicker, velvety skin

acanthosis nigricans

can acanthosis nigricans be treated?

once the underlying cause is treated - usually through diet change and increase in activity - the skin problem is resolved

PCOS is associated with which conditions?

1. obesity

2. hyperandrogenism

3. hyperinsulinemia

this condition often results in excess body hair, acne, and elevated levels of testosterone in women

failure of ovulation appears to be due to cysts that develop in ovaries and the condition is accompanied by menstrual irregularities

PCOS

true or false: PCOS and non-alcoholic fatty liver disease can both be improved with weight loss and exercise

true

this is a program offered by McMaster's children hospital that can help with childhood obesity

McMaster children's exercise and nutrition centre

the McMaster children's exercise and nutrition centre program started to involve kids with which conditions?

1. asthma

2. diabetes

3. muscular dystrophy

4. spina bifida

how can you get referred to McMaster's children's exercise and nutrition centre program?

referrals are typically from community physicians and pediatricians

children in McMaster's children's exercise and nutrition centre program work with a team of clinical staff including which roles?

1. registered dietician

2. behaviour therapist

3. exercist physiologist

4. physician

what is the average length of a treatment program at McMaster's children's exercise and nutrition centre program?

1 year

true or false: diets are part of the CENC

false - they are not because diets fail - the only way to permanently reduce weight is to change eating behaviours for good and increase levels of physical activity

when someone is dieting, what happens to basal metabolic rate?

it drops in response to a decrease in availability in food but this causes weight to be quickly regained with previous food levels are reinstated

what kind of lab work is typically done for children at the CENC?

1. lipid panel

2. insulin panel

3. blood glucose panel

4. body fat measurement in conjunction with height and weight

why is percent body fat a better measure than height and weight for children?

children grow over time and their height and weight changes

this is the gold standard for weighing in the CENC

underwater weighing (past method)

bioelectrical impendance (current method)

performed every 2 months

bioelectrical impendance is a measurement of what?

body water - you can then calculate percent body fat from that

what is the target level of total cholesterol for children and adults?

adults < 5.2mmol/L

children < 4.4 mmol/L

what is the target level of LDL cholesterol for children and adults?

adults < 3.0mmol/L

children < 2.8 mmol/L

what is the target level of HDL cholesterol for children and adults?

adults males and children > 1.0mmol/L

females > 1.3 mmol/L

what is the target level of triglycerides for children and adults?

adults < 1.7mmol/L

children < 1.4mmol/L

what is the target level of fasting glucose?

4.0-6.0mmol/L

what is the target level of glucose after a 2hr meal?

5.0-8.0mmol/L

What is the target level of hemoglobin A1c?

less than 6%

this is the gold standard for measurement of percent body fat

underwater weighing - requires specialized equipment and is difficult to do with children

what are the main methods of measuring percent body fat?

1. underwater weighing

2. triceps skinfold thickness test

3. bioelectrical impedance

What is the main issue with using the triceps skinfold thickness test to measure percent body fat?

not reliable, can vary greatly depending on who is measuring

this is a way of measuring body fat percentage that uses a stand on device or handheld device and is easy to use with children

bioelectrical impedance

true or false: exercising an hour before consumption of a high fat meal reduces blood triglyceride levels vs a high fat meal with no exercise

true

true or false: translocation of insulin transporters to the cell surface has been shown with exercise alone, independent of insulin binding

true - this allows more glucose to be taken up by muscle cells to fuel further activity

at the CENC, children typically go home after a visit with 3 goals - what are they?

1) a nutrition goal

2) a physical activity goal

3) a family goal

what are the 3 recommendations that the CENC makes for most families?

1) caution on sweet drinks

2) become more physically active (at least 45 min per day with 30 moderate and 15 vigorous)

3) no second portions at mealtime - 20 minute rule

describe the 20 minute rule

it takes up to 20 min for the brain to signal from the stomach that its full - eat and then wait 20 min

the sensory perception of an empty feeling that promotes food seeking behaviour

hunger