Term
How are obesity, insulin resistance, and hypertension related? |
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Definition
-Obesity cause increased lipolysis which leads to increased blood FFA
-This causes increased blood VLDL, LDL, and TG (and decreased HDL)
-Increased FFA also causes increased PPARy activation, increased fatty acid oxidation, and decreased glucose utilization
-All of these lead to insulin resistance, which leads to elevated insulin in the blood (insulinemia) -->sympathetic nervous system stimulation to balance osmotic pressure--> increased sodium and water retention and vasoconstriction --> Hypertension |
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Term
What happens if there is inadequate carbohydrates in the diet? |
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Definition
Dietary amino acids will be used for GLUCONEOGENESIS rather than protein synthesis |
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Term
What is the role of carbohydrates in the diet? |
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Definition
-First: used to supply energy -Any excess: converted to glycogen and TGs (storage fuels) |
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Term
What long term adaptations occur in low carbohydrate diets? |
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Definition
-elevated expression of enzymes in gluconeogenesis -increased fatty acid oxidation -increased amino acid catablolism |
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Term
What long term adaptations occur in high carb diets? |
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Definition
-increased expression of enzymes in the PPP -increased triglyceride synthesis
**consistent carb intake leads to consistent amounts of glycogen stores |
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Term
What are methods of carb loading for athletic endurance? |
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Definition
-Physical endurance can be increased by higher levels of glycogen stores; manipulate this through carb intake
-one method: for 3-4 days before, eat low carb diets, then day before eat meal with very high carbs
-increase glycogen by 2.5x and endurance by 4x
-improved method: continue normal diet/training for 2-3 days before competition, then eat very high carbohydrate meals and taper off the amount of training |
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Term
What are the general dietary recommendations for diabetics? |
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Definition
-General recommendations were abandoned and have been replaced with more individualized recommendations -some experience better control with high monounsat fat and low carbs -fat is not necessarily bad for all diabetics |
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Term
What are some of the different forms of carbohydrate intolerance? |
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Definition
Diabetes: intolerance to glucose and simple sugars
Digestive enzyme insufficiencies: Lactase insufficiency - Lactose intolerant - 30% occurrence
ALL PEOPLE: -limited a-galactosidase for legume digestion -no B-glucosidase for cellulose digestion |
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Term
Where do Omega-3 EFAs come from? |
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Definition
fish oils, but also plant (linolenic) |
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Term
Where do Omega-6 EFAs come from? |
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Definition
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Term
Describe EFA deciciency in humans. |
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Definition
-most common symptom is scaly dermatitis -very rare and has only been seen in people completely dependent on synthetic diets (infant formula, total parenteral nutrition); deficient formulas have since been replaced -very little EFA is needed to avoid deficieny; Omega 3 or 6s can function for this |
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Term
Diets high in ________ fats are most effective for producing insulin resistance. |
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Definition
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Term
Diets high in _____________ and ____________ fats improve membrane lipid fluidity, lower serum cholesterol, and lower risk of CV disease |
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Definition
polyunsaturated and monounsaturated fats |
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Term
Dietary recommendations of fats focus on what ratio? |
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Definition
unsaturated:saturated (higher ratios of unsaturated:saturated are healthier -- saturated = bad) |
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Term
High fat diets are associated with increased incidence of what types of cancer? |
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Definition
-prostate, breast, and colon -might be secondary to insulin resistance and obesity that is also associated with high fat diet |
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Term
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Definition
Fiber is the non-water part of the diet that is not easily digested or absorbed. All fiber comes from plants |
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Term
Where can water insoluble fiber be found? |
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Definition
Rich in cereal brans and veggies: -cellulose (B-1,4-glucose) -hemicellulose -lignins(waxes) |
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Term
Where can water soluble types of fiber be found? |
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Definition
**slowly digestable: gums (in oats & legumes) pectins (in fruits) |
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Term
What are the health benefits of water insoluble fiber? |
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Definition
1. Increase stool bulk (prevents constipation and cancer risk by decreasing transit time) 2. Bind carcinogens and cholesterol and prevents their absorption |
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Term
What are the health benefits of water soluble fiber? |
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Definition
1. Decrease rate of gastric emptying, slowing nutrient absorption (decreases glycemic index) 2. Decrease serum cholesterol (via metabolism) |
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Term
What are the dietary components that increase LDL and blood cholesterol? |
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Definition
-saturated fatty acids -trans-fatty acids -cholesterol |
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Term
What are the dietary components that decrease blood TGs and cholesterol? |
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Definition
-omega-3 PUFA -omega-6 PUFA -mono-unsaturated fatty acids (especially oleate) |
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Term
Why can omega-3 PUFA (fish oils) decrease heart attacks? |
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Definition
-Arachidonate (omega-6) --> PGI2 and TXA2
-Eicosapentaeinoic acid (20:5) (omega-3) -->PGI3 and TXA3
-PGI3 is a stronger anti-aggregator than PGI2
-TXA3 is a weaker platelet aggreagator than TXA2
-->Omega-3 PUFA (fish oils) can decrease heart attacks |
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Term
Explain the health affects of dietary components versus reality. |
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Definition
INDIVIDUALLY, some components offer health benefits if consumed in large amounts - ie, fiber, fish, and plant oils
INDIVIDUALLY, some components are harmful in the amounts they are normally consumed in (animal products)
In reality, an extremely large change in diet of one component is not largely accepted by people, because the diet is a lot to change just to obtain a modest change in risk of illness
Best and most effective diets are those with moderate changes in many components |
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Term
What causes the variation in the rise of blood glucose of different foods? Which foods do this the fastest? |
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Definition
-the variation is caused by the rate at which the fuels displace blood glucose utilization
-carbs do this the fastest because of the quick rate at which they are digested and absorbed -carbs also produce the biggest increase in blood glucose |
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Term
What is glycemic index and why is it useful for diabetics? |
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Definition
-glycemic index gives information on the size of blood glucose elevation for various kinds of foods
-since diabetics are intolerant of elevated blood glucose, this information is useful to them
Glycemic Index = (increase in blood glucose that 50g of the food causes)/(increase in blood glucose that 50g of glucose causes) x 100%
Examples:
glucose = 100
sucrose = 59
milk = 34
banana = 62 |
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Term
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Definition
Glycemix index * Grams of Carbohydrate per serving |
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Term
What are the macronutrient dietary recommendations for optimal health? |
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Definition
fiber: 25-30g/day from multiple sources to vary type
protein: 12% of calories but from mixed sources to reduce sat. fats and choelsterol and increase PUFA
Increase carbs to decrease fat intake |
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