Obesity Flashcards
Obesity is defined as a BMI over?
30kg/m2
Hormonal imbalance is often incriminated in women after menopause or when on the contraceptive pill however most of this weight gain is?
Small and often due to water retention
Which hormone is secreted from fat cells is thought to act as a feedback mechanism between adipose tissue and the brain acting as a lipostat and controlling fat stored through the regulation of hunger and satiety?
Leptin
A 10.5kcal daily excess would lead to how much weight gain over 20 years?
10kg
Following a meal which hormones are secreted from the small intestine?
Cholecystokinin, bombesin, glucagon-like peptide 1 (GLP-1), enterostatin and somatostatin
Following a meal which hormones are secreted from the pancreas?
Glucagon and insulin
Which gland in the body is the main regulatory of body weight?
Hypothalamus
Which peripheral appetite suppressing signals act centrally to activate the appetite suppressing pathway (while also inhibiting the appetite stimulating pathway) following a meal?
Insulin and Leptin
Insulin and Leptin hormones circulate in proportion to what?
Adipose tissue mass
Peptide YY (PYY) is produced by L cells by which organs in proportion to the energy ingested?
Distal small bowel and large bowel
PYY is thought to ____ appetite?
Decrease
Other than PYY which other appetite suppressing signals are produced y the gut in a nutrient dependent manner?
Oxyntomodulin and Glucagon-like peptide 1
How many amino acids does Ghrelin contain?
28-amino-acetylated peptide
Where is Ghrelin produced in the body?
Oxyntic cells in the fundus (top dome) of the stomach
Is the circulatory concentration of Ghrelin high or low before a meal?
High and is reduced following the consumption of energy or glucose - Unlike PYY which inreases after a meal
Unlike insulin and leptin, Ghrelin is ______ related to the individuals BMI?
Inversely related - lower BMI means more Ghrelin
Which situations cause the increase in Ghrelin?
long term exercise, very low calorie diets, anorexia nervosa and both cancer and cardiac cachexia
Which peptide produced by the same gene that encodes ghrelin counteracts the increase in food intake induced by ghrelin?
Obestatin
What are the two main pathways in the arcuate nucleus?
- The central appetite stimulating (orexigenic) pathway which expresses Neuropeptide Y (NPY) and agouti pathway-related protein (AgRp)
- The central appetite suppressing (anorexigenic) pathway in the upper arcuate nucleus which stimulates and proopiomelanocortin/cocaine-and-anfetamine-regulated transcript (POMC/CART)
Is BMR higher in obese or lean individuals
Obese because they are associated with a higher lean body mass
Do lean or obese individuals exert more energy during physical activity?
Obese because they have more mass to move
Do lean or obese individuals have a reduced dietary-induced thermogensis?
Obese which also means they tend to favour energy deposition
When stimulated by cold or food, brown adipose tissue in animals dissipates the energy derived from ingested food into?
Heat
What are considered normal tricep skinfold thickness measurements in a man and a woman?
20mm in a man, and 30mm in a woman
Fat located centrally, especially inside the abdomen are more sensitive to?
Lipolytic stimuli
What should be amended on a sphygmomanometer if measuring an individual with a large arm circumference?
A larger cuff - to reduce artefacts in the data
Which criteria has lower cut-off points for waist circumference (~25kg/m2) and lower fasting blood concentrations meaning it identifies at-risk patients at an earlier stage?
International Diabetes Foundation Criteria
Which factors are measures to determine metabolic syndrome?
Waist circumference, Triglycerides, HDL cholesterol, Blood pressure and fasting glucose
Many obese individuals oscillate in weight meaning they regain the lost weight and then lose it again in a cycle which increases their risk in the development of?
Coronary Artery Disease
Many dietary regimens aim to produce a weight loss of approximately ___ per week?
1kg
Initial weight loss is greater due to?
Accompanying glycogen and protein breakdown and consequent water loss
After 3-4 weeks weight loss may be small due to?
Only adipose tissue being broken down and less accompanying water loss
Short term weight loss is faster on which type of diet?
Low carbohydrate diet due to greater loss of body water, which is regained when the diet stops
Very low fat diets are often deficient in which vitamins and mineral?
E and B12 and in zinc
What effect does a low fat diet have on HDL and LDL?
Increased HDL and decreased LDL
What effect does a low carb diet have on HDL and LDL?
Greater decrease in HDL and triglyceride and no change on LDL
Are liquids more or less satiating than solid foods?
Less
Which drug, licensed for obesity in 2015 is a pancreatic
and gastric lipase inhibitor?
Orlistat
Bariatric or metabolic surgery is a treatment option for those with BMI?
> 40kg/m2 or >35kg/m2 with obesity-related complications
What are the main three groups of gastrointestinal surgical procedures?
- Restrictive (gastric banding)
- Malabsorptive (reduce ability to absorb nutrients)
- Restrictive + Malabsorptive
