Obesity Flashcards
% of men and women overweight in the UK
44% men
34% women
% of men and women obese in the UK
23% men
23% women
what are the components of daily energy expenditure in sendentary person
8% thermic effect of feeding
17% energy expenditure of PA
75% resting energy expenditure
what are the components of daily energy expenditure in a PA person
8% thermic effect of feeding
32% energy expenditure of PA
60% resting energy
relationship between EE and fat free mass
as fat-free mass increases REE increases
e.g obese have greater REE
norml BMI
18.5-24.9
overweight BMI
25-29.9 kg/m2
obesity BMI
obese 1 - 30-34.9
obese 2 - 35-39.9
obese 3 - >40
relationship between BMI and %body fat
as BMI increases, body fat increases in general
realtionship between BMI and CV mortality
as BMI increases risk increases
3 step increases for each chnage in BMI classification
obesity and diabetes
greater prevealance of T2D in obese
excess body fat leads to insulin resistnce
possible genetic predisposition
why does excess body fat lead to insulin restistance
Adipose tissue creates demand for insulin – increase fat deposition
Chronic high blood sugar down regulates insulin receptors
Fats block insulin receptors, leading to insulin resistance
Fat tissue, especially visceral fat, has a role in promoting diabetes
obesity and hypertension
often associated
for every 10% increase in body weight, systolic BP increases 6.5mmHg
6x more prevelant in obese
obesity and blood cholestrol
each kg of fat, approximatley 20mg/dl of cholestrol is synethiesised
obesity and respiratory disease
Burden of excess fat on thorax makes breathing more difficult and reduces lung volume
Hypoxia develops initially , hypercapnia can also develop reduced respiratory drive
Sleep apnea and snoring are common
obesity and orthopeadic problems
Strong positive correlation between arthritis and obesity
Every 5kg ↑ in weight, increased knee arthritis by 35%
Energy cost of movement is much greater in the overfat
Sedentariness becomes habitual leading to atrophy of muscles
fat but fit
If you are over fat then being aerobically fit helps reduce risk
Mortality rates are low in obese / overweight if fit
Metabolically healthy but obese (MHO) phenotype
Should not assume just because obese they are unhealthy 15-30% obese are MHO
CVD risk appears to be no higher in MHO compared to normal healthy normal weight adults
Causes of obesity
Genetic
Metabolic
Over eating
↓ Physical activity
Cause of obesity: Genetic
Faulty Leptin production or resistance
Leptin a hormone, which ↓ appetite, secreted from body fat in proportion to the number of body fat stores.
An increase in body fat causes an increase in leptin production, which suppresses intake, which should lead to a decrease in fat and therefore leptin production.
Cause of obesity: Meatabolic Factors
Some obese persons have a lower metabolic rate
Can be caused through defects; hypothyroidism, Cushing’s syndrome (overproduction of cortisol).
Metabolic control of appetite may go wrong
Food intake is controlled by orosensory, gastrointestinal & neuroendocrine factors.
Defects in these pathways may lead to dysregulation of appetit
effects of parents on child weight
If both parents obese, 70-80% chance of child being obese.
Mother more critical.
If neither parent obese, 14% chance of being obese
what is the set point theory
Body defends a certain weight like a thermostat regulates temperature
Normally returns back to that weight
Passive consumption
Individuals allowed to eat ad-lib diets that contain different fat levels will consume more energy on the high fat diet than on high CHO diet
- People tend to consume the same weight/volume of food at each meal and are unable to sub-consciously adapt to varying energy densities
- The same volume of a high fat (energy dense) meal will provide many more calories than the same volume of a high CHO meal
benefit of a 10% weight reduction
↓ > 20% total mortality (diabetes related and cancer deaths) ↓ 10 mmHg systolic BP ↓ 20 mmHg diastolic BP ↓ fasting blood glucose ↓ 10% total cholesterol ↓ 15% LDL cholesterol ↓30% triglycerides ↑8% HDL cholesterol
Goals of weight management
Prevent further weight gain (minimum goal).
Reduce body weight.
Maintain a lower body weight over long term.
background info required before starting weight loss
Background - occupation, family circumstances
Motivation- why they want to lose weight
Treatment expectations- what do they hope to achieve? Are they realistic?
Confidence- are they confident that they will succeed?
Knowledge- nutritional awareness, benefits of weight loss
Weight- agree goal weight
Previous dieting & weight-loss history
Exercise – likes / dislikes
Effect of PA for weigth loss
Modestly contributes to weight loss- Strong evidence
Decreases abdominal fat - Good evidence
Increases CV fitness - Strong evidence
benefits of regular PA in obese people
Decreases loss of fat-free mass associated with weight loss
Improves maintenance of weight loss
Improves cardiovascular and metabolic health, independent of weight loss
effect of exercsie alone for weight loss
Modest weight loss of 2-3kg
If energy intake is held constant, greater weight loss seen
effect of diet only for weight loss
Diet alone produces more weight loss than exercise alone treatments
Mean weight loss with diet only 1 -12 kg
effect of exercise and diet for weight loss
When exercise + diet are combined = greatest reduction in fat mass
Mean weight loss with diet + exercise combined 3 - 15kg
exercise considerations
Aggravation of pre-existing conditions (Hypertension, angina, arthritis etc.)
Orthopaedic problems
Avoid high-intensity and high-impact exercise energy cost orthopaedic problems
Avoid agility and balance exercises
Inappropriate food choices post exercise - food intake as a reward for exercise
Avoid high ambient temperatures
Be sensitive to body image, physical confidence issue - where and when they exercise
aim for overweight and obese people
↑ calorie expenditure = ↑ duration x ↑ frequency x ↓ intensity
Expend an accumulated 1000-2000 Kcal.wk-1
Expend 200-500kcal each exercise session
frequency of exercise
3+ days a week
exercise guidelines - time
20-60 mins
broken up into 3-10 minute sections
exercise guidlines - intensity
40-70% VO2 or HRR
55-65% HRmax
RPE 11-14
exercise guidlines - type
any aerobic
weight bearing and non weight bearing
resistance training - 2d/wk
- 1-2 sets of 8-15 reps
