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59 Cards in this Set
- Front
- Back
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What BMI = obesity?
What body fat % in men = obesity? What body fat % in women = obesity? |
BMI = >30
Men = 25% Women = 30% |
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Name two forms of obesity?
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Hyperplastic obesity
Hypertrophic obesity |
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What is hyperplastic obesity?
What does this number depend on? When does it usually begin? |
An increased number of fat cells throughout the body
This number largely depends on the diet of the mother while the person was still in the womb and early nutrition Usually begins in childhood |
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What is hypertrophic obesity?
Where is the usual fat distribution? What is this type of fat distribution called? (2) If the waist is larger than the hips whats it called? |
An increase in the size of each fat cell
The usual fat distribution is around the waist This is called male patterened or android as its usually seen in the male If the waist is larger than the hips its called android obesity |
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What type of obesity is it caled if the hips are larger than the waist?
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If the hips are larger than the waist the person has female patterned or gynecoid obesity.
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BMI formua?
2 problems? |
W/H2
Overestimates if excess muscle Underestimates if low muscle and fat |
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BMI Underweight?
BMI normal? BMI overweight? BMI obese? BMI extreme obesity? |
BMI underweight = <18.5
BMI normal = 18.5 - 24.9 BMI overweight = 24.9 - 29.9 Obese = 30 - 39.9 Extreme obesity = >40 |
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When measuring waist circumfrance when is it measured?
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On exhaling
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When is diabates screened for?
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When waist circumfrance is >94cm in white and black men
When waist cicrumfrance is >80cm in white, black and asian women When waist circumfrance is >90cm in asian men |
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Waist/hip ratio formua?
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Waist/hip
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BMI vs waist/hip ratio? (2/3)
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More sensitive than BMI in predicting health risk
Cheaper and easier to calculate Allows for same boundary values |
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Name two things visceral abdominal fat has?
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Higher number of adrenergic receptors
Contains large insulin resistant adipocytes |
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Formula for increased plasma adipocytes?
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Increased insulin mediated anti lipolysis + Increased catecholamine mediated lipolysis = increased circulating levels of non esterified fatty acids in plasma
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Explain why VAT may be seen as an endocrine gland?
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VAT produces large numebrs of pro and anti inflamatory factors including:
adipokines including leptin, adiponectin and resistin tumor necrosis factor alpha Interleukin 6 |
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3 factors that control appetite?
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The mechanical strength of the stomach
Hormones made by adipocytes such as leptin Neuropeptides made by the brain such as NPY Other hormones |
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What produces leptin?
How is a constant amount of body fat achieved? What does leptin also do? |
Adipocytes when they're full of TAG
The signally pathway of leptin to the CNS/hypothalamus Leptin also downregulated NPY |
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What is leptin resistance?
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When leptin doesnt work to control fat levels due to over eating/poor receptor sites on hypothalamus. Usually leptin tells the body to burn fat.
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Name three wasys leptin resistance happens?
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1. Bad fat
2. Increase in sugar, grains 3. Toxins These things blunt receptors on hypothalamus. |
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What does high circulating levels of leptin do?
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Loss of its characteristic anorexic action within the hypothalmic region of th ebrain
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How might increased triglycerides impair leptin/cause leptin resistance?
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Impairs transport of leptin across the blood brain barrier
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What do low GL diets do for leptin?
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Increase leptin sensitivity
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Where is gherlin produced?
Two things gerlin does? In obese patients why is gherlin low? |
Produced in the fundus in the stomach
Long term regulation of energy and short term regulation of feeding - increasing food intake? In obese patients gherlin may be low due to the high caloric intake (to try to reduce eating). |
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Where is adiponectin produced?
Name three things ti does? |
Adiponectin is produced by adipocytes.
It could supress the development of atherosclerosis, liver fibrosis and may play a role as an anti inflamatory hormone. |
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In many cases what is the cause of excess fat?
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Insulin resistance
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Explain simply the positive feedback cycle for fat. (5)
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1. Insulin resistance
2. Central adiposity 3. Alterations in adipokine secretion by adipocytes and gut derived hormones 4. Impaired diet induced thermogenesis 5. Low brain serotonin levels |
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Name 3 things insulin stops?
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Gluconeogenesis
Glucogenolysis Lipolysis |
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Name 3 things insulin increases?
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Glycolysis
Protein synthesis Glucose uptake in muscle and adipose tissue |
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Name a common denominator in insulin resistant patients?
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Excess fatty acids
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How is insulin sensitivity increased?
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By any activity that reduces the amount of fatty acids in the body.
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Apart from transporting glucose, what else is insulin important for? How is this achieved? (2)
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Control storage and release of fatty acids in and out of adipocytes. This is achieved by regulation of several lipase enzymes and activation of GLUT4.
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What is the backbone of a triglyceride simply? In more detail? How is this made?
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Glycerol is the backbone of a triglyceride. Alpha glycerol phosphate produced from glucose in fat cells.
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Simultaneously what do fat cells take up?
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Glucose and fatty acids.
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What doesGLUT 4 do?
What is this sensitive to? |
Transports glucose.
Insulin |
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What does adiponectin do?
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Adiponectin increases the oxidation of fatty acids/break down.
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Whatis the primary target for insulin?
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Muscle
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What happens to fat in insulin resistance in the liver?
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Continual fat synthesis causes the liver to synthesise and store fat, exporting more to the blood stream.
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Normally, what two signals does insulin send to the liver?
In insulin resistance what happens to these signals? |
Inhibit gluconeogenesis
Store the glucose available in the blood as glycogen In insulin resistance these signals respond poorly to the signal from insulin |
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What is the HPA axis?
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Hypothalamus pituitary adrenal axis
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What may be the link between obesity and insulin resistance?
Name two mediators that may impair insulin action? |
Inflamation
TNF alpha and interleukin 6 |
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How may these mediators effect insulin action/resistance?
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TNF a and IL6 inhibits aconitase in the krebs cycle leading to ATP deficiency and fat gain
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Name two ways inflamatory meditors and cytokines can effect insulin resistance/fat?
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TNFa, IL6, inhibits aconitase in teh krebs cycle leading to ATP deficiency
Inflamatory mediators like CRP interfere with insulin signalling pathways |
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What do PARRS do to inflamation?
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Reduce inflamatory cell infiltration
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Name 3 gut derived food inhibiting hormones?
What releases these? |
Neuropeptide Y
Glucagon like peptide 1 CCK Fibre |
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What is food induced thermogenesis?
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How much of the food ocnusmed is immediately converted to heat
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How does low serotonin effect diet?
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Low serotonin causes the brain to interpret this as starvation stimulating the appetite control centres which makes people crave carbohydrates. Then eating carbs causes increased tryptophan delivery to the brain
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Name 3 physiological reasons that may hinder fat loss?
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Low thyroid function
high or low cortisol Inflamation |
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What increases satiety the most?
What increases CCK the most? What increases lean muscle mass the most? What most strongly increases thermogenesis? |
Protein
Protein Protein Protein |
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What does HCA mean?
Dose? What does it do? |
Hydroxycitrate
1500mg Inhibits the conversion of carbs into fat |
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What may make some people genetically predisposed to obesity?
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Tryptophan hydroxylase
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How do omega 3's help fat loss?
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Stimulate lipolysis in the liver
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What does insulin do to thermogenesis?
What may stimulate thermogenesis? |
It blunts the effect
Green tea |
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How does ALA cause weight loss?
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Decreases hypothalmic AMPK activity
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How does ammenorhea happen in anorexics?
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The body stops causing GnRH surges and the menstrual cycle ceases.
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As a nutritional therapist how can you help an anorexic?
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You must work as an integrated team and must get permissio to contact the patients doctor first.
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How might zinc deficiency effect anorexia?
What may effect anxiety in anorexics and what might help? |
Prevents the release of NPY
Zinc defiiecny as zinc is needed to convert glutamate to gabba |
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How is leptin associated with diabetes?
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Leptin causes fat breakdown, but certain things can cause the receptors on the hypothalamus to be damaged so the body cant break down fat.
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What bad fats cause leptin resistance?
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Trans fats, oxidised vegetable oils
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How does sugar cause leptin resistance?
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Causes inflamation on cell membrane
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How can toxins cause diabetes/insulin resistance and leptin resistance?
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Blunt the receptors
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