nutrition

obesity

Obesity

Clinical assessment and investigations

Quantify the problem

Exclude an underlying cause
Identify complications
Reach a management plan.

Obesity

• Quantify the problem
(BMI) the body mass index
(waist circumference) abdominal obesity
A waist circumference of > 102 cm in men or > 88 cm in women indicates that the risk of metabolic and cardiovascular is high.


Bioimpedance
CT SCAN
Densitometry (under water weighing)

Obesity

BMI (kg/m2) Classification Risk of co morbidity
18.5-24.9 Normal range Negligible
25.0-29.9 Overweight Mildly increased
≥ 30.0 Obese
30.0-34.9 Class I Moderate
35.0-39.9 Class II Severe
≥ 40.0 Class III very severe

Obesity

• 3. Exclude an underlying cause
The Obesity-Focused History
A dietary history obtained by a specialist dietitian
The patient's current diet and physical activity
Drug-induced weight gain should also to be considered
specific symptoms of secondary causes of obesity


Obesity
The Investigation
Thyroid function tests (all patient)
Serum cortisol (Cushing's syndrome)
Dexamethasone suppression test
24-hour urine free cortisol
Genetic counseling
Monogenic and 'syndromic' causes (children presenting with severe obesity)

Obesity

• 3.Identify complications
Assessment of cardiovascular risk factors
Blood pressure
measuring blood glucose
serum lipid profile
Serum transaminases (NASH)

Obesity

• Management plan
The Goal of Therapy
improve obesity-related comorbid conditions
reduce the risk of developing future comorbidities.
The target
initial weight-loss goal of 10% over 6 months .
The decision to treat depend
BMI
patient's risk status
expectations (capacity to change)
available resources.
Modalities
lifestyle management
pharmacotherapy
surgery

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Obesity

Lifestyle management
Behavioral Therapy
new dietary and physical activity behaviors.
Strategies :
maximizing physical activity (e.g. walking rather than driving to work)
Changes in eating behavior including
food selection
portion size control
avoidance of snacking
regular meals to encourage satiety

Obesity

Physical activity
Exercise alone is only moderately effective for weight loss
Moderate exercise( brisk walking) 60m./5 times/week/1 year produce minimal wt loss
Moderate intensive( treadmill walking, bicycling)45m./5 times/week/1year produce 5kg loss
The most important role of exercise appears to be in the maintenance of the weight loss.

Obesity

Weight loss diets
In obese patients, more active intervention is usually required to lose weight before conversion to 'weight maintenance' advice

low caloric diet is the cornerstone of the obesity treatment

They all involve a reduction of daily total energy intake of (500-1000 kcal) from the patient's normal consumption.
The goal is to lose 0.5 kg/week.

Obesity

Very low calorie diets (VLCDs) are recommended for short-term rapid weight loss, producing losses of 1.5-2.5 kg/week
Energy content should be a minimum of (500 kcal) in VLCD

There is no role for starvation diets, which risk profound loss of muscle mass and the development of arrhythmias

Obesity

Diet % carbohydrate % fat % protein
Normal 55 30 15
Moderate fat 60 25 15
Low carbohyd. 10 60 30
High protein 43 30 27
Low fat 70 13 17


low-carbohydrate diets appear to be at least as effective as low-fat diets in inducing weight loss for up to 1 year.

Obesity

Strategies:
choosing smaller portion sizes
selecting leaner cuts of meat and skimmed dairy products
drinking water instead of caloric beverages.
reducing fried foods and other added fats and oils
Eating Low energy dense food
fruits and vegetables
Avoid high energy dense food
high-fat foods such as pretzels, cheese, egg yolks, potato chips, and red meat.

Obesity

Pharmacotherapy:
Indications:
BMI ≥30 kg/m2
BMI ≥27 kg/m2 with concomitant comorbidities
Dietary and physical activity therapy not successful
Types:
1. Suppression of appetite via centrally active medications
2. Second strategy is to reduce the absorption of selective macronutrients such as fat.
3. Selective blocking of the endocannabinoid


Obesity
Centrally Acting Anorexia Medications
sibutramine (Meridia) : central serotonin and norepinephrine reuptake inhibitor
Benefit:
loss of about 5–9% of initial body weight at 12 month
maintain weight loss for up to 2 years.
Side effects:
headache, dry mouth, insomnia, and constipation.
dose-related increase in blood pressure and heart rate
Contraindications:
uncontrolled hypertension
congestive heart failure
symptomatic coronary heart disease
arrhythmias, or history of stroke

Obesity

Peripherally Acting Medications
Orlistat (Xenical) is a synthetic derivative of a naturally occurring lipostatin( lipase inhibitor)
slowly reversible inhibitor of pancreatic, gastric lipases
orlistat blocks the digestion and absorption of about 30% of dietary fat.
Benefit:
orlistat produces a weight loss of about 9–10%,
GI tract adverse effects
flatus
fecal urgency, oily stool
increased defecation
Serum concentrations of the fat-soluble may be reduced


Obesity

Cannabinoid receptor antagonist

Rimonabant acts in the hypothalamus to reduce appetite

Side effects :

exacerbate or induce depression
associated with a small increased risk of suicide

Obesity

Surgery (Bariatric surgery )
most effective weight-loss therapy for severe obesity.
produce 30–35% body weight loss that is maintained in nearly 60% of patients at 5 years.
weight loss is greater after bypass than gastric surgery
positive impact on obesity-related morbidities ass DM, HT and obstructive sleep apnea

Obesity

Indications:
BMI > 40 kg/m2)
BMI > 35 kg/m2) associated with a comorbidities.
Weight-loss surgeries :
Restrictive
partial gastrectomy( sleeve gastroec).
Laparoscopic gastric banding


Restrictive-malabsorptive.
Roux-en-Y gastric bypass

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© 2005 Elsevier

Downloaded from: StudentConsult (on 6 December 2011 05:10 PM)

© 2005 Elsevier


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