Lifestyle and disease: Advising patients on obesity Flashcards
What is meant by ‘locus of control’?
Generalised expectancy that rewards are controlled by external forces or by one’s own behaviour (internal vs. external)
What is the health belief model?
Action is a function of perceived likelihood of illness, its
seriousness, and costs and benefits of action
What is self-efficacy?
Belief in ability to succeed, task specific
What are the stages of change? (5)
Pre-contemplation (happy with status quo)
Contemplation (thinks about change)
Preparation (getting ready)
Action (attempting change)
Maintenance (doing well) or Relapse (back to old ways – the typical outcome)
List three things that can be done to help people change their behaviours (in order of increasing intensity and decreasing population impact).
Health promotion (schools, mass media, leaflets) Advice by doctors Specialist treatments - e.g. drug clinics (smoking, alcohol, hard drugs), obesity treatments
What is the efficacy of lifestyle interventions determined by? (4)
Strength of the drive for the unhealthy behaviour
Effort required
Target population - motivation, social factors, personal characteristics, biological factors
Efficacy of supportive medication
Explain why the lifestyle interventions in obesity are limited.
Strength of drive - STRONG, hunger is the prototype of other drives e.g. when addicted to drugs. This force is difficult to modify.
Effort required - adhering to exercise regime isn’t as easy as putting on sunscreen for example
Target population - well motivated but varied resources and varied barriers
Efficacy of supportive medication - still waiting for a breakthrough in obesity, e.g. with smoking medication is more effective than for alcohol
Name some pulmonary and cardiovascular complications of obesity.
Idiopathic intracranial hypertension Stroke Coronary heart disease Diabetes Dyslipidemia Hypertension Phlebitis - venous stasis Pulmonary disease - abnormal function, obstructive sleep apnea, hypoventilation syndrome
Name some gastrointestinal/hepatic complications of obesity.
Nonalcoholic fatty liver disease - steatosis, steatohepatitis, cirrhosis
Gall bladder disease
Severe pancreatitis
What cancers are linked to obesity? (8)
Breast, uterus, cervix, colon, esophagus, pancreas, kidney, prostate
What gynaecologic abnormalities are complications of obesity?
Abnormal menses, infertility, polycystic ovarian syndrome
Other complications of obesity.
Cataracts
Osteoarthritis
Gout
How does BMI relate to hazard ratio for death from any cause in healthy never-smokers?
Increased if BMI over 25, and continues to increase
Also increased if BMI under 20
What is interesting about the Flegal et al. JAMA 2013 meta-analysis?
It showed that BMI>34 is associated with increased all-cause mortality compared to normal weight, but ‘grade 1 obesity’ (BMI=30-35) is not. It showed that being overweight (BMI=25-30) is associated with lower mortality.
What are the benefits of weight loss?
Can reduce blood pressure
Can prevent the onset of type 2 diabetes
Can reduce blood glucose and LDL cholesterol
Can improve sleep apnoea
When do benefits of weight loss start to accrue?
When 5-10% of initial body weight is lost
Explain the energy equation.
A – B = C
A = Energy in (food), B = Energy out (burned, metabolism), C = Energy stored (as fat)
i.e. if energy in is more than energy burned, you gain weight
How much weight gain does 1% energy over-consumption cause over 10 years?
~50 kg of weight gain per decade
What is the basal metabolic rate for women?
1200-1600 kCal per day
What is the total energy expenditure for most women (office work)? What does this include?
2000-2500
Exercise, NEAT (non-exercise activities, e.g. fidgeting), thermal work (shivering, sweating), effect of eating and digestion
What influences resting metabolic rate?
Increases with increased muscle mass
Declines with age
Declines during restriction of energy intake
What increases/decreases resting metabolic rate?
Increases with increased muscle mass
Declines with age
Declines during restriction of energy intake
What determines our body weight?
Interaction of behaviour, genes and environment
How heritable is BMI?
Around 50%
What environmental factors contribute to obesity?
Unrestricted access to food
Advertising of and easy access to fattening food
Sedentary lifestyle
Lack of opportunity to exercise
Describe different measures of success in terms of weight loss.
Patient wants to lose weight very quickly and maintain it
NICE vs OECD - gradual weight loss and maintain, or allowed to slowly creep back up
Lecturer - take 10 year approach, ups and downs but gradual decrease over 10 years
What rate of weight loss is achievable?
Websites claim 8lbs/week
Patient wants 2-4 lbs/week
Weight Watchers, British Dietetic Association - says 1 lb/week
In reality… patients manage 0.5 lb/week
Behaviour Modification in weight management - three steps?
1) developing specific and realistic goals that can be easily monitored
2) developing a plan of action
3) making manageable incremental changes to provide an experience of progress and success
Give some examples of self-monitoring strategies. (3)
Food diaries to record type and amount of food eaten, and times, place, and feelings associated with eating. This by itself generates a small weight loss.
Pedometers to monitor physical activity
Scales to monitor body weight regularly – essential for any progress.
Give some examples of stimulus control strategies. (3)
Identifying and modifying environmental cues to eating, e.g. limit eating to kitchen, with no TV on to raise awareness of what and how much is eaten.
Remove snacks from TV room
Keep tempting food out of sight
Give an example of a goal setting strategy.
e.g. 5% weight loss over 6 M/losing 1lb a week = REALISTIC
What does cognitive restructuring involve? (2)
Identifying and changing self defeating thoughts (I am too weak-willed to get very far; without my comfort eating I’d be a nervous wreck, etc.)
Challenging inaccurate beliefs
Give examples of incentives used in weight loss.
Agreements/contracts with HPs, friends, slimming group, etc.
Rewards for achieving goals
Praise, awards for benchmark achievements
Weight Loss Maintenance - Predictors of Success.
Successful slimmers: 90% used diet & activity 400 kcal/day in activity Average 5 eating episodes/day [inc breakfast] 75% weighed at least 1/week
Calories expended by 100kg person after 30 minutes of swimming?
440
Calories expended by 100kg person after 30 minutes of aerobics?
300
Calories expended by 100kg person after 30 minutes of house cleaning?
180
Physical activity recommendations?
30 minutes moderate activity on 5 or more days a week
Up to an hour/day may be needed to prevent obesity
Up to 90 minutes/day to maintain weight reduction
How many steps a day is associated with weight loss?
10,000 steps/day = 4 to 5 miles
Define a sedentary lifestyle in terms of steps/day.
Under 5,000
How does orlistat work?
Blocks absorption from the gut of about 1/3 of fat which has been eaten. If too much fat is eaten, there is oily
leakage, flatulence with spotting, diarrhoea. This
teaches people which food contains fat.
Who can have Orlistat Rx (Xenical)?
> 12 years of age, BMI>30 or >27 with risk factors (hypertension, diabetes, dyslipidemia).
What is the dose of Orlistat Rx (Xenical)?
120mg, TID with meals containing fat
Who can have Orlistat OTC (Alli)?
18 years of age, for weight loss when used with reduced calorie and low-fat diet
What is the dose of Orlistat OTC?
60 mg TID with meals containing fat
Side effects of orlistat?
Diarrhea and steatorrhea - minimized by maintaining a strict low fat diet
In a small proportion of users (1%-5%), may reduce intake of fat soluble vitamins. To prevent this, recommend a multivitamin if used for over 2 weeks.
Name some ineffective diet products.
Fat blockers, magnet diet pills Starch blockers Diet patches Spirulina Ephedra
What is Ephedra?
Amphetamine like stimulant
Raises BP, HR
Linked to heart attacks, strokes and death
Banned in 2003, but available via the internet
What is the role of dietary fat?
Fat = least satiating nutrient
Highly palatable
High energy density
How many calories does 1g of fat contain?
9
How many calories does 1g of protein or 1g of carbohydrate contain?
4
How many calories does 1g of fibre contain?
2
How many calories does 1g of alcohol contain?
7
Do low fat approaches work?
What is the problem?
Low fat ad libitum –> 10% reduction in fat, 3-4kg loss in normal to overweight, 5-6kg weight loss in obese
BUT Relative effectiveness of low fat ad libitum versus low fat energy restricted remains unclear
Food industry promotes low fat foods that are not necessarily low energy
Explain the current opinions on fat and CVD.
Fat = CVD hypothesis not confirmed
Recommendations to avoid saturated fats are
considered still current, but saturated fats seem to have no association with heart disease
Low fat trial - how does this compare the current opinions on fat and CVD?
The intervention did not produce weight loss, no reduction of risk of CHD or stroke
How does sugar affect weight?
Reduced intake of dietary sugars was associated with a decrease by 0.80 kg in body weight. Conversely, increased sugar intake was associated with an increase of 0.75 kg.
Compare sugar with fat in terms of CHD.
Consuming moderate amounts of sugar increases triglycerides (linked to CHD) compared to the consumption of moderate amounts of saturated fat
What is fructose linked to?
Gout, diabetes, weight gain, metabolic syndrome
Hypertension, rotten teeth
High triglycerides, dyslipidaemia, CVD
May ↑ hunger by causing diet-induced leptin resistance (satiety hormone)
What is glycaemic index?
GI is the effect of carbohydrate foods on postprandial glycaemia
Are low GI diets effective?
No RCT’s in management of obesity, but epidemiological studies support low GI diets for CHD & diabetes risk reduction
Are low carbohydrate diets effective?
“we know little of its effects or consequences”
“ no long term evidence to support their use”
“insufficient evidence to support their adoption”
What is the Atkin’s Diet?
Max 20 grams of carbohydrates/day
Protein and fat ad-lib
Some concerns about safety, but weight loss in people who are able to adhere to it
Meal Replacement Approaches - do they work?
Yes, seem to in studies BUT heavy health professional support and the studies provided the products free of
charge
Very Low Calorie Diets - what is the mean wt change over 4-20 weeks? Do they work long term?
9-26kg
Conflicting evidence on effectiveness in long term
Maintenance more likely if used with drug or behavioural therapy
Difficult to adhere to, close monitoring needed
Intermittent fasting (IF) - what are the supposed benefits?
Restricted calories increase longevity in mice (probably by lowering a growth hormone IGF-1)
Can lead to good weight loss and may lead to better health
Disadvantages of IF?
Requires serious effort and not researched so far
What is time restricted eating?
Food is consumed only within a specific window each day e.g. 16:8 rule.
How is obesity treatment selected?
If BMI 25-26.9 - diet, exercise, behavior Tx
If BMI 27-29.9 - diet, exercise, behavior Tx, plus pharmacotherapy if comorbidities (e.g. type 2 diabetes, sleep apnoea, hypertension, or arthritis requiring joint replacement)
If BMI 30-34.9 - diet, exercise, behavior Tx, plus pharmacotherapy
If BMI 35-39.9 - diet, exercise, behavior Tx, plus pharmacotherapy, plus surgery if comorbidities
If BMI over 40 - diet, exercise, behavior Tx, plus pharmacotherapy, plus surgery
Name some appetite suppressants. (5)
Methylcellulose
Amphetamine derivatives – withdrawn
Sibutramine (SSRI derivative) – withdrawn
Rimonabant (cannabis antagonist) – withdrawn
GLP-1 agonists, successful in diabetes and effective in weight loss
What is Liraglutide (Victoza®)?
Glucagon-like peptide agonist for the treatment of patients with Type 2 diabetes, and now for weight loss
How does Liraglutide (Victoza®) work?
Daily subcutaneous injection
Makes patients feel more full and satisfied with less food
It also reduces the speed by which the stomach empties, which also makes patients less hungry
Side effects of Liraglutide (Victoza®)?
Most patients have none
Some reported nausea and vomiting (generally short-lived)
Concerns that Liraglutide may cause thyroid tumours and reports of pancreatitis
Name some Malabsorption inducers. (3)
Orlistat
Acarbose
Glycosuria
Name two metabolic stimulants.
Thyroxine
Beta-agonists
Gastric Bypass/Roux-en-Y Bypass - how does this work?
Restrictive and malabsorptive
LAP band - how does this work?
Restrictive
Roux-en-Y Bypass vs LAP band - which causes more weight loss?
RYGB
Possible aftermath of gastric bypass?
Skin flaps
Post surgery addictions to gambling, alcohol, narcotics (RARE)
