- Who should be treated?
- How is treatment of obesity and overweight beneficial?
- Assessment of the obese or overweight individual.
- What are the goals of treatment?
- What are the treatment options?
Who should be treated?
All adults > 18years of age with BMI > 25kg/m2 are considered
at risk. Treatment of overweight is recommended only when patients
have two or more risk factors or a high waist circumference. Assessment
of a patient's absolute risk status requires examination for the
presence of associated disease conditions.
Patients with following conditions are classified as being at
very high risk for disease complications and mortality.
- Established coronary heart disease (CHD),
- Other atherosclerotic diseases,
- Type 2 diabetes, and
- Sleep apnea.
How is treatment of obesity and overweight beneficial?
Obesity and overweight are associated with increased morbidity
and mortality. There is strong evidence that weight loss in overweight
and obese individuals reduces risk factors for many diseases.
Weight loss is beneficial as it-
- reduces blood pressure in hypertensive individuals
- reduces serum triglycerides
- increases high-density lipoprotein (HDL)-cholesterol
- reduces total serum cholesterol
- reduces low-density lipoprotein (LDL)-cholesterol
- reduces blood glucose levels
Assessment of the obese or overweight individual
When assessing a patient for risk status and as a candidate for
weight loss therapy, patient's BMI, waist circumference, and overall
risk status should be taken into account. Patient's motivation
to lose weight should also be considered. Any previous attempt
at weight loss should be reviewed. Patient's understanding of
the complications of obesity should be considered.
What are the goals of treatment?
The general goals of weight loss and management are:
- to prevent further weight gain
- to reduce body weight, and
- to maintain a lower body weight over the long term.
The initial goal of weight loss is to reduce body weight by ten
percent in 6 months of therapy. It has been studied that a decrease
of 300 to 500 kcal/day, results in weight loss of about 1/2 to
1 lb/week, that is ten percent reduction in 6 months, in overweight
patients with BMI in the range of 27 to 35.
For more severely obese patients with BMI > 35, deficits of
up to 500 to 1,000 kcal/day will lead to weight loss of about
1 to 2 lb/week and a 10 percent weight loss in 6 months.
After 6 months the rate of weight loss reduces. In fact it may
become stable inspite of therapy because a lesser energy expenditure
at the lower weight.
Weight maintenance program consisting of dietary therapy, physical
activity, and behaviour therapy should be continued indefinitely
otherwise weight is usually regained.
After 6 months if more weight loss is needed then another attempt
at weight reduction should be made. This requires further adjustment
of the diet, physical activity and pharmacotherapy.
What are the treatments options?
1. Dietary therapy
Diet should be individually planned, taking into account the patient's
overweight status. The patient must remain on low calorie diet
(LCD) for a long time otherwise weight is regained.
Diet must be nutritionally adequate. Depending on the BMI, a
reduction in total calorie by 300 to 1,000 kcal/day is required
to achieve 10 percent reduction in weight in 6 months.
Reducing dietary fat, along with reducing dietary carbohydrates,
usually will be needed to produce the caloric deficit needed for
an acceptable weight loss. Besides decreasing saturated fat, total
fats should be 30 percent or less of total calories. To minimise
nitrogen loss the diet should contain at least 0.8 to 1.2gm of
protein per kilogram of desired body weight. Food high in fibre
should be used as it is low in calorie content. Refined sugars
should be minimised as these provide calories without any vitamins
or minerals.
Very low calorie diets (VLCD) - These limit daily intake to 300-700
cal/day. Some diets are limited to proteins and are called protein
supplemental modified fasts (PSMF). The weight reduction is rapid
with these diets but they can have serious side effects like orthostatic
hypotension, fatigue cold intolerance, dry skin, hair loss and
menstrual irregularities in women. Crash diets are often ineffective.
2. Physical activity
Most of the weight loss occurs because of decreased caloric intake
but increase in physical activity is important for prevention
of weight regain. In addition to maintenance of reduced weight
it benefits by reducing cardiovascular and diabetes risks beyond
that produced by weight reduction alone.
Obese patients are generally inactive, they should be encouraged
to increase activity. Exercise should be started gradually and
increased over a period of time. The patient can begin with simple
exercise like walking. The exercise can be done all at one time
or intermittently over the day. All adults should engage in at
least 30 minutes or more of moderate-intensity physical activity
everyday. Moderate exercise does not increase food intake in obese
as it does in lean individuals. Therefore it is helpful in induction
and maintenance of weight loss.
3. Behaviour modification
In behaviour modification the obese patient should be first made
aware of what and how much he or she eats, as many times a person
eats without giving a thought to the calorie content of the food.
Patient should be educated to monitor the quantity of food eaten
and when, where, with whom, it is eaten. All this should be analysed
and discussed with the patient.
New modes of eating are suggested to the individual, like, not
eating between meals, eating slowly, watching the portion eaten
etc. The aim is to reduce food intake.
Behaviour change includes increased physical activity. Behavior
modification also strives at stimulus control, cognitive restructuring
and environmental management. This therapy is usually done in
groups.
4. Phamacotherapy
Available evidence indicates that certain drugs can augment the
benefits of LCD, physical activity, and behaviour therapy in weight
loss. There is general agreement that drug therapy should be used
in patients with a BMI of >= 30 with no concomitant risk factors
or diseases, and in patients with a BMI of >= 27 with concomitant
risk factors or diseases.
Drugs for obesity treatment should be prescribed only to patients
who understand that life-long vigilance towards diet and physical
activity is required for sustained weight loss. Continual assessment
of the patient by the physician for efficacy and safety of the
drug is essential.
The drugs that have shown efficacy in management of obesity and
are available for use are as follows:
(a) Anorexiant drugs: These drugs reduce appetite by acting
centrally through the brain neurotransmitter pathways. Weight
loss with these is rapid initially but then it reaches a plateau,
probably due to the limit of their therapeutic effect. They are
generally used for maintainance of weight loss.
Potential for abuse, tolerance and adverse effects like increased
risk of pulmonary hypertension should be considered before use
of these compounds.
Fenfluramine hydrochloride and combination have been taken off
the market after studies showing their association with cardiac
valvulopathy. Among the available anorexiants, Phentermine (resin)
has demonstrated efficacy in long term placebo controlled trials.
(b) Sibutramine: It is a serotonin and noradrenaline reuptake
inhibitor that increases energy expenditure and satiety. Its weight
loss effects are primarily mediated by its noradrenaline action
because pure selective seretonin reuptake inhibitors have not
been shown to produce long-term weight loss.
Several studies have demonstrated that Sibutramine enhances weight
loss modestly and helps facilitate weight loss maintenance. It
is generally well tolerated. However, there is a marginal increase
in heart rate and blood pressure with its use.
(c) Orlistat: This drug acts by inhibiting pancreatic
lipase and thus reducing absorption of fat in the intestine. Side
effects include steatorrhoea, loose, frequent stools, fecal urgency
and fecal incontinence. Fat-soluble vitamins need to be suplpemented
as there is partial malabsorption.
5. Surgery for weight reduction
Surgery for weight reduction is indicated in patients with clinically
severe obesity, i.e., BMI >= 40 or >= 35 with comorbid conditions.
It is reserved for patients in whom pharmacotherapy has failed
to achieve weight loss and who are suffering from the complications
of extreme obesity.
The surgical options are gastric restriction (vertical gastric
banding) or gastric bypass (Roux-en Y). Guidance on diet and physical
activity prior to and after the surgery is important to achieve
benefit. Behavioural and social support should be provided to
the patient.
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