Obesity Flashcards
Define obesity and overweight
Excess body fat
Healthy weight — BMI of 18.5–24.9 kg/m2.
Overweight — BMI of 25–29.9 kg/m2.
Obesity 1 — BMI of 30–34.9 kg/m2.
Obesity 2 — BMI of 35–39.9 kg/m2.
Obesity 3 — BMI of 40 kg/m2 or more.
Aetiology of obesity
Lifestyle and overnutrition: large portion size, sedentary lifestyle, eating disorder, MHx
Endocrine: hypothyroidism | Cushing’s syndrome | PCOS | Diabetes mellitus | GH deficiency
Prader-Willi syndrome
Down’s syndrome
Laurence-Moon-Biedl
Leptin deficiency (<3yo and severely obese)
Medications: corticosteroids | lithium | antipsychotics | anticonvulsants | insulin | antidepressants | beta blockers
How does obesity threshold change with ethnicity
Use lower BMI thresholds as a practical measure of overweight and obesity in people with a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background, as they are prone to central adiposity and their cardiometabolic risk occurs at lower BMI:
Overweight — BMI 23 kg/m2 to 27.4 kg/m2.
Obesity — BMI 27.5 kg/m2 or above.
Obesity classes 2 and 3 — reduce the BMI thresholds by 2.5 kg/m2.
When should caution be taken in BMI interpretation
Adults with high muscle mass (less accurate measure of central adiposity in this group)
>65yo, taking into account comorbidities, conditions that may affect functional capacity, and the possible protective effect of having a slightly higher BMI when older.
Investigations for obesity
Weight-height ratio - estimate of central adiposity, predicts future health risk (>0.6 = high)
Urine dip: ?glycosuria
Lipid profile
TFTs
GH
Cortisol
US/CT/MRI head
Polysomnography
Management for overweight
Low waist circumference: general advice on weight and lifestyle
Large waist circumference (>80cm): structured advice regarding physical advice and diet (behavioural interventions)
BMI >27 + RF (T2DM, HTN, dyslipidaemia) → drug therapy
Consider the need for referral to weight management services (tier 2 services) or specialist obesity services (tier 3 services)
Management for obesity I
Structured advice regarding physical advice and diet (behavioural interventions)
+ RF (T2DM, HTN, dyslipidaemia) → drug therapy
Consider the need for referral to weight management services (tier 2 services) or specialist obesity services (tier 3 services)
Consider bariatric surgery:
T2DM + BMI 30-25
Management for Obesity II/III
Structured advice regarding physical advice and diet (behavioural interventions)
Drug therapy
Consider the need for referral to weight management services (tier 2 services) or specialist obesity services (tier 3 services)
Consider bariatric surgery:
BMI >50 → first line = bariatric surgery
What behavioural interventions may be used
Self-monitoring of behaviour and progress.
Stimulus control.
Goal setting.
Slowing rate of eating.
Ensuring social support.
Problem-solving.
Assertiveness.
Cognitive restructuring (modifying thoughts).
Reinforcement of changes.
Relapse prevention.
Strategies for dealing with weight regain.
What lifestyle advice should be given for obesity
Healthier eating
5 portions of fruit and vegetables a day
Starchy meals (bread, pasta, rice, potatoes)
Moderate milk and dairy (low fat)
Moderate protein-rich foods e.g. meat, fish, eggs, beans, lentils
Reduce consumption of foods high in fat
Reduce alcohol consumption
Physical activity
Reduce time spent inactive
At least 30 minutes of moderate intensity on 5 days a week or more
Consider gardening, brisk walking, cycling
Consider supervised exercise programmes
What is the drug treatment for obesity
First line: Orlistat 120mg with water
Second line: Liraglutide (Saxenda)
What is the surgical management for obesity
Bariatric surgery
Considered for:
- Those who have achieved or nearly achieved maturity
- BMI >40
- BMI 35-40 + complications
- All other interventions have failed
- fit for anaesthetic and surgery
- can commit to a long-term follow up
Complications of obesity
Orthopaedic - slipped upper femoral epiphysis, tibia vera (bow legs), abnormal foot structure and function
Idiopathic intracranial hypertension
Hypoventilation syndrome (daytime somnolence, sleep apnoea, snoring, hypercapnia, heart failure)
Non-alcoholic fatty liver disease
Gall bladder disease/gallstones
PCOS
T2DM
Hypertension
Abnormal blood lipids
Asthma
Changes in left ventricular mass
Increased risk of malignancy: breast, endometrial, colon
Psychological: low self-esteem, teasing, depression
Metabolic syndrome: insulin resistance, atherogenic dyslipidaemia
