Weight Management & Eating Disorders Flashcards
What is BMI?
- body mass index
- calculated by dividing weight in kg by height in m
- healthy range is 18.5 to 24.9
- overweight defined as 25 to 29.9
- obesity is >30
- kids use growth charts
Are those with a higher BMI always at risk for chronic diseases?
- no; sometimes people just have a high muscle mass
- BMI does not measure body composition or fat percentage
Why is location of body fat important?
- health risks increased when fat stored in abdominal region (visceral fat)
- pear-shaped better than apple-shaped
What dictates where fat is deposited?
- mainly genes
- influenced by stress, smoking, and alcohol use
Why is visceral fat harmful?
- metabolically active, pumps out adipokines and TNF-alpha
- close to surrounding organs, between and around organs
- subcutaneous fat around hips and thighs less harmful
What waist circumference is correlated with increased health risk?
Men: >102 cm/40”
Women: > 88 cm/35”
- Asian ethnicity targets are lower because cannot tolerate as much visceral adiposity without adverse effects
What determines our weight?
- balance between energy taken in and energy expended
- if we expend more than we consume, we lose weight, and vice versa
- also more complex than this as well
What is the minimum amount fo weight loss to recommend for health?
5% of body weight - will return client to normal glycemic state
What nutrients are used first in a meal?
- protein first, they provide substrates for protein synthesis in cells
- next, carbs are used to replenish glycogen stores and provide glucose to tissues
- extra converted to TGs
- fat is last
Why is fat favourable to store?
- provides the most calories per gram
- no process to change it when ingested
Why do physically active people have greater caloric needs?
- need more energy
- muscle uses more energy than fat
What is total energy expenditure (TEE)?
- total amount of calories used
- includes basal metabolic processes, metabolism of food and activity
Energy used for activity includes…
Exercise and non-exercise activity thermogenesis (NEAT)
What is the thermic effect of food?
- energy expended in digestion, absorption, metabolism and storage of ingested macronutrients
What effect does starvation or fasting have on BMR?
Decreases BMR
Can we determine if someone needs to make lifestyle modifications based on weight?
No; should also measure waist circumference
Stress, fever, and illness have what effect on BMR?
Increases BMR
What is the correlation between excess body fat and disease risk?
- overweight have 1-1.5x greater risk
- risk sharply increases with obese or extremely obese individuals
What is leptin?
Hormone that signals whether or not to take in more food and expend more or less energy
Leptin levels are proportionate to…
Fat levels in the body
How is leptin related to insulin?
Insulin levels are thought to affect the release of leptin and work with leptin to control body fat levels
Leptin in obese individuals?
There is plenty of leptin, but it does not seem to inhibit food intake or increase energy output as in normal weight individuals
What is the leptin feedback mechanism ?
- weight loss decreases leptin, results in increased intake and decreased expenditure
- weight gain increases leptin, results in decreased intake and increased expenditure
What hormones are involved in food intake regulation?
- leptin
- GLP-1 (similar to glucagon)
- ghrelin (stimulates hunger)
- CCK
Why is there an increase in obesity, and why are children affected?
- increase amount of food consumed, along with decrease in exercise
- processed fast food is becoming normalized
- children affected due to the diet and activity of their parents
- reduction in physical education, computer and video games, parental concern for safety
- proportion distortion
If BMI < 25…
No weight loss needed
If BMI 25-29.9 and waist circumference > 35 or 40…
Assess for at least two obesity-related risk factors; if present weight loss recommended
If BMI > 30…
Weight loss recommended
What tool can be used to stage people with obesity?
- EOSS (Edmonton Obesity Staging System)
- stage 0-4
- based on obesity-related risk factors, physical symptoms, psychological symptoms, and functional limitations
What is yo-yo dieting?
- process of repeatedly going on fad diets to achieve rapid weight loss
- results in decreased in BMR, fatigue, and food cravings
- when person returns to former eating habits, will gain weight back due to low BMR and overeating
- cyclic, repetitive nature
- better to adopt small, healthy, realistic habits and eating patterns
Are overweight clients always overnourished?
No; if eating unhealthy foods then can be undernourished at the same time
Behaviour modification is…
- the goal of any lifestyle intervention
- short-term fad diets unlikely to permanently change behaviour or maintain weight loss
- fad diets generate money for the inventor
- slow, sustainable changes have better results
Plant-derived protein and fat…
Is associated with lower mortality
Both high and low carbohydrate diets…
Are associated with high mortality
What is an effective strategy for monitoring eating behaviours?
Keeping a diet log or journal
What is bariatric surgery?
- GI tract is altered to reduced food intake and nutrient absorption
- gastric banding or gastric bypass
When is bariatric surgery indicated?
- indicated for extremely obese persons with BMI > 30
- need to have some sort of limitation to which other attempts at weight loss have failed
- more and more of these surgeries being done
What is gastric banding?
- band tightened or loosened over time to change size of opening from esophagus to stomach
- allows less food to be consumed at one time, comfortably, and slows the rate of stomach emptying
What is gastric bypass?
- most common type of bariatric surgery
- size of stomach is effectively decreased to limit intake
- length of the small intestine is shortened, which limits absorption
- reattached to upper new stomach pouch
- lifelong changes must be made in eating habits and sufficient nutrients ingested, since absorption is decreased
What is gastric sleeve?
- 85% of outer stomach portion is removed
Why are eating disorders a problem today?
- constantly bombarded with images of thin, muscular models
- difficult to achieve with normal food intake
- inability to achieve this ideal leads to poor self image and self esteem
How have cultural body ideals changed?
- changed drastically from early 1900s, when fuller, more curvaceous figures were sought after
- models have become thinner and thinner
- the incidence of EDs have increased
- weights of models are about 25% lower than the average women, as opposed to 8% diference 40 years ago
What is distorted body image?
- difference between ideal and attainable causes individual to see themselves as fat
- leads to reduced food intake and weight restriction
Can individuals be genetically predisposed to eating disorders?
- yes; inherited susceptible personality traits, a body type that may not meet their ideal, hunger and satiety
- combines with societal pressures and ideals, low self-esteem, need for self-control, and distorted body image
- manifested as an ED during adolescence
What proportion of girls in grade 9 and 10 had tried to lose weight in last year?
30%
How many females will be affected by EDs in their lifetime?
3%
What are OSFEDs?
- other specified feeding or eating disorders
- covers disorders where clinically significant distress and impairment of functioning are present but criteria for other disorders not met
Malnourished individuals are at risk for…
Ongoing infections
What are the three main categories of eating disorder?
- anorexia nervosa
- bulimia nervosa
- binge eating
What is anorexia?
- persistent restriction of energy intake that leads to significantly low body weight
- intense fear of gaining weight or becoming fat
- disturbed body image
- new DSM-5 criteria have changed to drop amenorrhea
- subtypes include restricting and binge-eating or purging type
What is bulimia?
- repeated binging episodes, with a feeling of lack of control over eating
- repeated compensation after binging by vomiting, misuse of laxatives, or excessive exercise to prevent weight gain
- new guidelines say one episode per week for 3 months
- disturbed body image
What is the female athlete triad?
- pressures in certain sports, such as gymnastics, to maintain a lean, thin body can lead to energy restriction
- energy restriction and excessive exercise can upset hormonal balance
- low estrogen levels can cause amenorrhea
- osteoporosis is also a result of low estrogen levels due to low peak bone mass, premature bone loss, increased stress fractures
What are visible signs of vitamin C deficiency?
- bruising and bleeding under the skin
- due to collagen deficiency
