Obesity

Overview

Overweight and obesity are common worldwide and are associated with many conditions, particularly diabetes, hypertension and dyslipidemia. Overweight and obesity are defined as a moral or excessive fat accusation that presents a risk to health Obesity is now dramatically on the rise in low and middle-income countries.

Management should include diet, physical activity, and behaviour change components. Long term follow-up is needed. Bariatric surgery is a treatment option for some patients with severe obesity, particularly those with type 2 diabetes. Such patients should be assessed for their suitability for this treatment

Aetiology and Risk Factors

Aetiology

Multi-factorial
Energy intake > energy expenditure over a prolonged period
Intake – cultural expectation, food availability, financial resources, likes and dislikes, emotional (anger, boredom), lack of satiety, dieting -> food cravings
Change in Base Metabolic Rate (BMR)

Expenditure – Base Metabolic Rate (70%), thermogenesis (20%), exercise (10%). Base metabolic rate Approximately 1800 calories a day for 70kg man.Increase BMR – Sever exercise, fever, catecholamines, caffeine, thyroid hormones, smokingDecrease BMR – Age, female 10% below male, menopause.

Epigenetics
- Environmental factors are responsible for the increase in average weight of the population
- Genetic factors explain 30-50% of variation in body weight between individuals

Risk Factors

Genetic prediposition
Inactivity
Unhealthy diet and eating habits
Family lifestyle
Quitting smoking
Pregnancy
Lack of sleep
Certain medications:
- corticosteroids (e.g., prednisone)
- atypical antipsychotics
- certain antidepressants
- diabetes medications (like insulin)
- mood stabilizers (e.g., lithium)
> 40 yo
Social and economic issues
Hypothyroidism
Hypercortisolism
Corticosteroid therapy

Clinical Manifestation

Assess any environmental, social, and family factors, including family history of overweight or obesity and comorbidities.

Clinical Presentation

Varies

Physical examination

↑↑ BMI and Waist
Hypertension
Acanothosis Nigricans
Striae
Hepatomegaly
Gait and mobility issues
hypothyroidism?
Cushings disease?

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Assessment of weight and obesity

Adipocity (fat tissue) is an important measurement of body weight, not total body weight.
Body mass index (BMI) is a good, but imperfect measurement of adiposity.
- BMI = weight (in Kg)/ Height (m)2
Waist circumference is a useful indicator of central adiposity that can also be used to indicate cardio metabolic risk
Distribution of body fat is crucial (PEAR is better than APPLE)

Limitations of BMI on:

Muscular people

Elderly people

Young children (centile charts)

Classification	BMI	Risk of morbidities
Underweight	<18.5	Increased
Normal weight	18.5–24.9	Low
Overweight	>25	Increased
Obese I	30–34.5	Moderate
Obese II	35.0–39.9	Severe
Obese III	>40	Very severe

An adult’s waist circumference is measured halfway between the inferior margin of the last rib and the crest of the ilium in the mid-axillary plane. The measurement is taken at the end of normal expiration.

Diagnosis

Investigations

Investigate comorbidities and other factors to an appropriate level, depending on the person, timing of assessment, degree of overweight or obesity, and previous assessments.

Differential Diagnosis

Primary Hypothyroidism
Secondary Hypothyroidism
Cushing’s Disease
Glucocorticoid therapy

Treatment

Significant benefit (a reduction in mortality and morbidity) can be obtained with moderate weight loss (5-10%). Energy Balance is key!

Lifestyle modifications

Diet and eating habit
Physical activity
Behavioural modification

Pharmacotherapy

Medications can have an adverse effect on weight by influencing either food intake (hunger) or energy expenditure. Medication should be considered in people who have a BMI >25

Orlistat
Sibutramine
Phentemine (not good for long terms as risk of dependence and abuse increases)
Antidepressants
Antipsychotics
Insulin

Bariatric Surgery

The most effective treatment for the morbidly obese

Roux-en-Y Gastric bypass (30% of body weight lost)
Gastric banding -> can induce reflex -> Barrats -> adenocarcinoma
Sleeve Gastroectomy

Indications for Bariatric Surgery

Other approaches were unsuccessful

BMI >35

Understands surgery and risks

No uncontrolled psychological conditions

Dedicated to life-style change and follow-up

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Facts about obesity

Genetics factors play a big role, but heritability is not destiny. Life-style modification (environmental change) can promote weight loss as much as pharmaceutical agents available

Trying to go on a diet is effective in losing weight but generally does not work well in the long-term

Exercise increases health regardless of body weight or weight lost

Physical activity or exercise in a sufficient dose aids in long-term weight maintenance

Continuing doing things that promote weight loss helps maintain weight loss

Programs that involve overweight children and their parents help promote greater weight loss or maintenance

Meal replacement products help promote greater weight loss

Pharmaceutical medication can help with weight loss and maintenance as long as the agents continue to be used.

In appropriate patients, bariatric surgery results in long-term weight loss and reductions in the rate of incident diabetes and mortality

Complications and Prognosis

Complications

All-causes of death (mortality)
Metabolic Syndrome
Hypertension
Dyslipidemia
Type 2 diabetes
Coronary heart disease
Stroke
Gallbladder disease
Osteoarthritis
Sleep apnea and breathing problems
Some cancers (endometrial, breast, colon, kidney, gallbladder, and liver)
Low quality of life
Mental illness such as clinical depression, anxiety, and other mental disorders
Body pain and difficulty with physical functioning

Metabolic Syndrome is a cluster of risk factors comprising of excess abdominal weight, lipid abnormalities, hypertension and elevated glucose levels.