Obesity Causes and Consequences Flashcards
Which children are at a higher risk of obesity? (2)
. Small for date infants (controlled by in utero environment)
. Children who are overweight under the age of 5 years old, with at least one or both parents being overweight
. Also, overweight teenagers are more likely to develop into obese adults
Which factors put some females at a higher risk of obesity? (3)
Pregnancy, oral contraceptive, menopause
What is the general pattern for weight gain in males?
. Usually progressive increase in weight until 60s, weight stabilises between 55 and 64 years and then slowly declines
. Bit of weight gain in mid-years due to reduced activity and increased calorie intake
Give 3 lifestyle factors that can contribute to weight gain.
Sleep deprivation, smoking cessation (nicotine withdrawal leads to increased hunger), drugs (e.g. antidepressants, beta-blockers etc.)
Give 4 illnesses that induce weight gain.
Hypothyroidism, polycystic ovarian syndrome, Cushing’s syndrome, hypothalamic obesity (extreme insatiable appetite)
Give 4 monogenic causes of obesity.
Melanocortin-4-receptor defect, POMC gene defect, leptin defect, leptin receptor defect
What is a MC4R defect?
Melanocortin-4-receptor defect- associated with early onset obesity and taller than average height
What is a POMC defect?
Adrenal crisis in infancy leads to hyperphagia (insatiable appetite and excess eating) and thus obesity
What is leptin? What is the effect of a leptin gene defect?
Leptin is a hormone produced by adipocytes to inhibit hunger and give a sense of satiety. It signals to the brain the extent of fat in storage. Leptin defect associated with hyperphagia due to still feeling hungry and thus can lead to obesity.
What is a leptin receptor defect?
Leptin not detected so brain doesn’t receive signal or being full, leads to hyperphagia and obesity
What are ob/ob mice?
Mice with leptin defiency
What are db/db mice?
Mice with leptin receptor defect
What is the range for a normal BMI? What is the range for being obese?
Normal is 18.5-24.9
Obese is 30-39.9
Give three ways of assessing if someone is obese.
BMI, waist measurement, waist to hip ratio
What is visceral fat?
Deep fat in the abdominal cavity packed around organs
Why can visceral fat be dangerous?
. Excess visceral fat is associated with metabolic syndrome
. Metabolic syndrome means increased risk of hypertension, hyperlipidaemia (lots of fats and cholesterol in blood), impaired glucose tolerance which can progress to Type II Diabetes, CV problems
. Visceral fat also releases cytokines and hormones that can lead to insulin resistance and endothelial cell dysfunction and inflammation
What is considered a safe and sustainable rate of weight loss and how is this achieved?
. 0.5-1 kg (1-2lb) per week weight loss. This can be achieved by reducing calorie intake by 600 calories a day
. For most men, no more than 1,900 calories a day
. For most women, no more than 1,400 calories a day
Name two diet programmes that are generally considered unsafe unless supervised and monitored.
FAD diet (involves fasting and cutting out certain food groups) and VLCD (very low calorie diet)
How much exercise is recommended?
150 moderate exercise per week or 75 minutes intense exercise per week.
What is Orlistat?
Intestinal lipase inhibitor, reduces fat absorption
What is Liraglutide?
Reduces hunger by delaying gastric emptying
How does bariatric surgery influence weight loss?
Maximal weight loss seen 1-2 years after surgery, then weight increase occurs, which levels off after 8-10 years
Which organ releases ghrelin and what effect does ghrelin have?
Stomach, increases appetite
Which cells release leptin and what effect does leptin have?
Adipocytes, decreases appetite (satiety)
Give the organs involved in increasing and decreasing appetite.
. Stomach secretes ghrelin, which increases appetite
. Adipocytes, pancreas, small and large intestines secrete hormones which decrease appetite
