Obesity & Eating Disorders Flashcards
Define obesity.
Medical term for an accumulation of body fat which may have a negative affect on health.
Define overweight.
An excess of body weight relative to height.
How can sleep disturbances or lack of sleep contribute to the development of T2D?
Sleep loss = altered glucose metabolism.
Sleep loss = up-regulation of appetite.
Sleep loss = lower energy expenditure.
How can stress lead to weight gain?
During stress, eating behaviour can change for 80% of people - half eat less, half eat more. Common misconception that stress = weight loss.
What is Hyperplastic obesity?
Increased number of fat cells exist throughout the body. The number depends primarily on the diet of the mother while the person was still in the womb and early infant nutrition.
What is Hypertrophic obesity
An increase in the size of each fat cell.
Waist is larger than the hips = android obesity.
Hips are larger than waist = gynecoid obesity.
Visceral Abdominal Fat (VAT) is metabolically active and is therefore thought of as what? State 2 things is produces.
An endocrine organ.
- IL-6 (a pro-inflammatory cytokine).
- Tumour necrosis factor alpha (TNF-α).
- Adipokines such as cytokines, leptin, adiponectin, and resistin.
What is leptin? Explain covering TAG and neuropeptide Y.
A satiety hormone, regulates appetite and energy balance of the body. Produced by adipocytes when they are ‘full’ of tri-acyl-glycerides (TAG). Leptin acts at the level of the hypothalamus and down-regulates neuropeptide Y, leading to decreased hunger, increased activity and increased thermogenesis.
What is leptin resistance?
Desensitisation for the leptin signal.
How is the stomach directly involved in feeling of fullness?
The mechanical stretch of the stomach via the vagus nerve.
What is Ghrelin and how is it involved in obesity/eating?
Produced in the stomach and plays a role in long-term regulation of energy metabolism and the short-term regulation of feeding - increasing food intake. Low in obese individuals and high in underweight.
Explain Adiponectin’s role in hunger/feeding?
We have more adiponectin the less ‘full’ our fat cells. Lowered levels are also associated with insulin resistance.
State 4 actions of insulin.
- Inhibits gluconeogenesis (eneration of glucose in liver).
- Stimulates glucose uptake in skeletal muscle.
- Stimulates glycogen synthesis in skeletal muscle.
- Reduces hunger via the hypothalamus.
- Increases synthesis of liver glycogen, thereby increasing glucose uptake and storage.
- Stimulates synthesis of triglycerides from free fatty acids.
- Inhibits release of free fatty acids from triglycerides.
Discuss 5HT (serotonin) in relation to obesity.
Potentially a genetic predisposition for low activity of tryptophan hydroxylase which converts tryptophan to serotonin = natures own appetite suppressant.
Increased saturation of the muscle membrane with omega 3 fatty acids is associated with what?
Improved insulin sensitivity.