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NW ClinicalNutrition
NWHSU Winter 2015 Clinical Nutrition Final Questions
Question | Answer |
---|---|
How are fats different from carbohydrates? | • Lipids (fats) = more energy • Lipids = insoluble in water • Carbs = soluble in water |
What is a triglyceride? How fatty acids are transported and stored in the body | • 3 FA + glycerol (sugar) - - Main source of body fat |
What is a phospholipid? | • 2 FA + phosphate + glycerol (sugar) - - Cell membrane structure, High amount in brain |
What is the difference between saturated and unsaturated fatty acids? | • Unsaturated fatty acids have double bonds and saturated do not |
Name 3 functions of fatty acids in the body? | 1. Energy, calories, and heat 2. Cell membrane structure (phospholipids) 3. insulation and absorb shock |
What kinds of fats does the body make? | • Saturated fats, monosaturated fats, cholesterol |
What is the difference between omega-6, omega-3, and omega-9 fatty acids? | • Omega 3- anti inflammatory • Omega 6-pro inflammatory |
Why are omega-3 fatty acids sensitive to destruction? | • More double bonds |
What are the pros of the omega-6/omega-3 ratio? | • Pros - biomarker, it’s a problem |
What are the cons of the omega-6/omega-3 ratio? | • Cons - too simplistic, which one is good and which is bad? Some good some bad, appropriate inflammatory response, many ways to change the ratio |
What questions would you ask of fish oil manufacturers to determine if they have a high quality product? | Why is “less than acceptable limits” a selling point? Why is damage that occurs during fish oil processing not listen on your produce? |
What questions would you ask of fish oil manufacturers to determine if they have a high quality product? | What is the highest temp reaching during deodorization, molecular distillation, and wiped film evaporation? What is the time duration of these processes and how many repetitions are done? |
What are food sources of the various fatty acids? | • Flax, hemp, cold water fish, safflower, sunflower, liver, black currant, olive oil, avocado, coconut |
How is arachadonic acid a good and bad prostaglandin? | • Pro-inflammatory, central role in injury and disease states • Necessary for growth and repair of skeletal muscle |
What is the role of saturated fats in prostaglandin production? | • Saturated fats inhibit the production of prostaglandins |
Name 3 dangers of trans fatty acids? | 1. Lowers HDL cholesterol 2. Increase insulin resistance 3. Decrease immune response |
What are the enemies of fatty acids? | • Light, oxygen, heat |
What fatty acids are most stable? | • Saturated fatty acids, monosaturated fatty a cids, n6 then n3 |
What are the problems with refined vegetable oils? | • Natural substances are removed, vit e example, loss of vital nutrients, chemical modification |
Tendency to increase n6/n3 ratio | • Changes the structure/damaged moleculars -hydrogenation |
What is a benefit of refined vegetable oils? | • High temp cooking |
What determines the types of fatty acids found in plants and animals? | • Plant→ amount of sunlight, where does it grow • Animals→ what plants 4 or animals they eat |
What are characteristics of high quality oils? | • Fresh unrefined oils, mechanically pressed, cold expeller pressed, no oxygen or light during processing,storage and transport, tastes like seed |
Why can’t a triglyceride cross a cell membrane? | • Too big |
What are the functions of cholesterol in the human body? | Production of critical regulatory hormones Cortisol, DHEA, testosterone, estrogen, Vit D Complex role in metabolism Bile production Cell membrane hormones Low cholesterol is associated with cancer deaths, inflammation, anxiety, depression |
What antioxidant nutrients prevent against fat oxidation? | • Vitamin E (Zinc and selenium enhance absorption of Vit E) |
Compare and contrast HDL cholesterol and LDL cholesterol. | • HDL is good cholesterol, removes cholesterol from the cells, raising HDL more important than lowering LDL • LDL is bad cholesterol, brings cholesterol to the cells, increased need for cholesterol, oxidized LDL is deposited in arterial wall |
Name 3 risk factors for elevated cholesterol? | • Low fiber intake, high sugar intake, caffeine, stress, smoking, lack of exercise |
Carbohydrate Questions | "He who loses wealth, loses much. He who loses a friend, loses more. He who loses courage, loses all." - Cervantes |
Rank the simple carbohydrates according to sweetness. | Sweet scale (higher is sweeter) Fructose is sweet and fruity (130-180) Sucrose is the standard (100) Glucose sweet with bitter side taste (61-70) Maltose is sweet and syrupy (43-50) Lactose (15-40) |
What about hidden sugar? | Hidden sugar (fruit juice, soda) makes accurate assessment of dietary sugar difficult |
What is the monosaccharide composition of sucrose, lactose, and starch? | Sucrose (table sugar) = fructose + glucose Lactose (milk sugar) = galactose + glucose Maltose = glucose + glucose Starch (tubular grains) = glucose |
How does the liver work to maintain blood glucose - Major function? | • Major function of the liver is maintenance of blood glucose |
How does the liver work to maintain blood glucose - Regulation? | • Regulation is the net effect of the liver’s metabolic processes: o Remove glucose for glycogen synthesis or energy release o Return glucose to blood such as glycogenolysis and gluconeogenesis |
How does the liver work to maintain blood glucose - Hormonal Influence? | • Hormonal influence of: o Antagonistic pancreatic hormones insulin and glucagon o Glucocorticoid hormones of adrenal cortex (cortisol) |
How does the liver work to maintain blood glucose - Pathway? | Glucose is absorbed in to blood vessels in villi of small intestines → hepatic portal vessel carries glucose in blood to liver → glucose converted to glycogen and stored in liver → glucose released into blood to be carried to the cells of the body |
Glucose metabolism | • Limited storage of glycogen by liver • Liver is the great processor – very large surface area • Excess sugar not needed at that moment |
Protective pathway of glucose metabolism | • Excess glucose → fat • Fat is LESS damaging than sugar |
What is the difference between glycemic index and glycemic load? | Glycemic response – rate at which glucose is absorbed from the intestinal tract is important in blood glucose regulation o Degree of blood glucose elevation o % of time glucose is elevated impact on obesity, heart disease, diabetes |
GLYCEMIC INDEX | Provides qualitative comparisons of carbohydrate |
GLYCEMIC LOAD | Provides quantitative impact of carbohydrate on blood glucose |
What are factors that affect the glycemic response? | 1. starch gelatinization – less gelantinized (swollen) = lower GI 2. physical entrapment – fibrous coat around beans, seeds, and grains act as a physical barrier to digestion = lower GI |
What are factors that affect the glycemic response? | 3. high amylose content – high amylose (basmati rice, legumes) = lower GI 4. particle size – small particle = higher GI |
What are factors that affect the glycemic response? | 5. viscosity of fiber – soluble fibers ↑viscosity (thickness) = lower GI 6. sugar – difference between sucrose and starch; sugar restricts starch gelatinization = lower GI |
What are factors that affect the glycemic response? | 7. acidity – acids slow down stomach emptying = lower GI; sourdough bread, vinegar, lemon juice 8. fat – slows down stomach emptying = lower GI |
What are problems with glycemic index? | • Adding fats lower the glycemic index • Problems: - it’s too simple, - The low glycemic index of fructose is misleading - Doesn’t express the amount |
What is the difference between sugar and starch? (Sugar) | SUGAR Simple Carbohydrate (1-2) Low GI 50% glucose, 50% fructose |
What is the difference between sugar and starch? (Starch) | STARCH Polysaccharide/complex Higher GI All glucose, not very sweet |
What is the difference between sugar and starch? | GI focus on blood sugar rather than insulin Creates perception that sucrose is better than starch |
What is the difference between sugar and starch? | Dramatic increase in fructose consumption(Addition of fructose to a diet lacking carbohydrates-Replacement of the glucose from starch by the fructose in sugar) |
Why do cocoa puffs have a lower glycemic index than corn flakes? | • adding sugar or fructose to food lowers the glycemic index • the amount of fructose in cocoa puffs is greater than corn flakes |
What is the second meal effect? | Ability of 1 meal to improve the gluc tolerance of the next meal The 3pm slump as consequence of poor breakfast Must look at whole diet pattern instead of individual food selections Importance of meal frequency throughout the day for glucose tolerance |
What are simple strategies to balance blood glucose? | • low insulin production leads to blood glucose imbalance • don’t eat carbohydrate/sugar rich meals • change breakfast • add protein • add fiber • add fats • less carb • increase meal frequencies |
What is a problem with small, frequent meals? | • Potential for increasing calories • Overeating • Quick energy |
How does stress (specifically glucocorticoids and catecholamines) affect carbohydrate metabolism? | Glucocorticoids restores blood glucose levels (stress response) = ↑ gluconeogenesis |
How does stress (specifically glucocorticoids and catecholamines) affect carbohydrate metabolism? | Catecholamines (epinephrine/norephinephrine) indicates need for energy (exercise, stress) = ↑ glycogenolysis |
How does stress (specifically glucocorticoids and catecholamines) affect carbohydrate metabolism? | Other hormonal regulation: Glucagon restores blood glucose levels ↑ Hepatic gluconeogenesis ↓ Glycolysis ↑ Glycogenolysis insulin is major anabolic hormone = ↑ glycolysis |
What is a side effect of excessive sugar alcohol intake? | • GI side effects • Sugar alcohols – hydrogenated form of carbohydrate o Used to reduce “net carbs” in food replacements o Used as replacement or sucrose • Glycerol • Sorbitol • Xylitol • Mannitol |
Compare and contrast high fructose corn syrup and sucrose. | • The two are almost biochemically identical. HFCS has free monosaccharides, whereas sucrose has disaccharides. |
Name 3 adverse effects of dietary fructose. | 1. Non-alcoholic fatty liver disease 2. Functional bowel disturbances 3. Metabolic syndrome (hypertension, elevated triglycerides and LDL, insulin resistance) |
How does fructose induce lipogenesis? | • Fructose targets the liver, which converts it to triglycerides. Fructose blocks glucose metabolism in liver and the synthesis of glucose into glycogen. |
How does fructose induce lipogenesis? | This creates a glucose traffic-jam in the liver and the muscles compensate by becoming more insulin resistant. This leads to long term (indirect) damage on blood sugar regulation. As short term, fructose has no effect on glucose or insulin. |
What is the difference between glucose and fructose? | • Glucose: all cells use it, secretes insulin, savory, higher glycemic index, starch, less glycation • Fructose: only the liver uses it, no insulin, sweeter, lower glycemic index, fruits and sweeteners, more |
What are the 5 artificial sweeteners available in the United States? | 1. Aspartame (NutraSweet, Equal) 2. Saccharin (Sweet n Low) 3. Sucralose (Splenda) 4. Acesulfame Potassium (Sweet One) 5. Neotame |
What are the 2 other sweeteners used in the United States | 1. Stevia 2. Xylitol |
What is the difference between water-soluble and water-insoluble fiber? | • Water-soluble fiber dissolves in hot water. It delays gastric emptying, increasing transit time (through slower movement), and decreases nutrient absorption. Hemicellulose, pectin, gums, and β glucans are examples |
What is the difference between water-soluble and water-insoluble fiber? | • Water-insoluble fiber doesn’t dissolve in hot water. It decreases transit time and increases fecal bulk. Hemicellulose, cellulose, and lignin are examples. |
Why is a high-fiber diet beneficial? | • Hydration capacity and viscosity; adsorption or binding ability; degradability/ fermentability |
Does fiber decrease the risk of colon cancer? | • Fibers aids in prevention: adsorption of carcinogenic bile acids, increased transit time, decreased pH, antimicrobial effects of SCFA |
Does fiber decrease the risk of colon cancer? | • Increased cancer risk of soluble fiber? Degradation of soluble fibers releases carcinogens; decreased absorption of bile salts may put GI epithelium at risk |
What is the nutrition transition? 1 | • 1. CURRENT: Changes in the food economy have contributed to shifting dietary patterns, for example, increased consumption of an energy-dense diet high in fat, particularly saturated fat, and low in carbohydrates. |
2. This combines with a decline in energy expenditure that is associated with a sedentary lifestyle…because of these changes in dietary and lifestyle patterns, diet-related disease | 3. (obesity, diabetes mellitus, cardiovascular disease, hypertensions, stroke, various forms of cancer) are increasingly significant causes of disability and premature death in both developing and newly developing countries. |
• 4. PREVIOUSLY: single common cause- the consumption of easily digestible, refined carbohydrates | 5. (foods that could be transported without spoiled or being devoured by rodents: sugar, molasses, white flour, and white rice), was rejected in 1970s due to conflict with lipid hypothesis |
What is the flaw of chronic disease epidemiology? 1 | Greater affluences takes populations through a nutrition transition; meat consumption increases, |
What is the flaw of chronic disease epidemiology? 2 | and so saturated fat increases tool; grain consumption decreases, and so carbohydrate consumption as a whole decreases; carbohydrates consumed are more highly refined |
What is the carbohydrate hypothesis? | 1. Obesity is caused by a regulatory defect in fat metabolism 2. Insulin plays a primary role in this fattening process and the compensatory hunger and fatigue 3. Carbohydrates are the prime suspects in the chronic elevation of insulin |
Compare and contrast the treatment approach to insulin resistance and hyperinsulinemia? Insulin resistance | Insulin resistance • Improve the function of insulin on the cell membrane o Increase energy o Decrease saturated fats and LDL o Oral hypoglycmeics (drugs, herbs, supplements) |
Compare and contrast the treatment approach to insulin resistance and hyperinsulinemia? hyperinsulinemia | Hyperinsulinemia • Lower the insulin by decreasing carb consumption o Fructose and alcohol reduction (primary o Starch reduction (secondary) |
How does weight gain protect against diabetes? | See Slides (page 40 slide 80) (page 42 slide 83) |
Protein Study Questions | No Act of Kindness, No Matter How Small Is Ever Wasted! -Aesop |
Why is animal protein considered wasteful consumption? | • Protein intake has remained the same sense 1900 but • % animal food intake has more than doubled sense 1900 • Cost of animal protein production is high making it wasteful |
What is the significance of nitrogen in protein? | • N is needed for synthesis of AA |
What is the difference between a glucogenic or ketogenic amino acid? | • Glucogenic = AA that can be converted into glucose through gluconeogenesis • Ketogenic = AA that can be degraded directly into acetyl CoA through ketogenesis |
What does it mean to call an amino acid “conditionally essential”? | • meaning they are not normally required in the diet, but are required at certain life stages or if you are genetically unable to synthesize certain amino acids or have a medical condition that prevents |
What determines the quality of protein? | 1. Amino acid composition 2. digestibility |
What is the digestibility of various protein sources? | 1.Measures amount of AA absorbed 2.Animanl proteins 90-99% digestible (Meat and cheese 95%) (Eggs = 97%) 3.Plant proteins = 70-90% digestible (Cooked split peas = 70%) (Tofu = 90%) |
Provide an overview of protein metabolism to include dietary intake, fecal loss, urinary loss, and protein recycling. | Check out slide 15 |
What is the significance of glutamine for the intestinal cells? | • used by intestinal cells as a primary energy source • synthesis of heat shock proteins (stress proteins) |
Describe the role of the liver in amino acid metabolism. | • Primary site of uptake 50-65% following a meal • Monitors and adjusts the rate of metabolism • Typically following a meal o 20% for synthesis of protein and other N-containing compounds o 80% for AA pool and subsequent deamination |
Describe the role of the liver in amino acid metabolism. | • Main site of catabolism of essential AA • Derives 50% of energy (ATP) from AA oxidation |
What is the significance of the branch chain amino acids? | • They are metabolized in the muscle rather than the liver |
What is the role of acute phase plasma proteins? | • Markers of inflammation • C-reactive protein |
What is the difference between transamination and deamination? | • Transamination- transfer of amino groups o Important for synthesis of nonessential AA o Catalyzed by amimotransferases o Depends on availability of alpha-keto acids |
What is the difference between transamination and deamination? | • Deamination – removal of amino groups o Primarily in liver o Excess protein intake o Amino group is converted to ammonia |
Describe the basic function of the urea cycle including how it is affected by diet and hormones. | • Urea cycle (ornithine cycle) o Produces urea from ammonia (NH3) • Removes ammonia from the body o Too much ammonia _ brain malfunction and coma |
Describe the basic function of the urea cycle including how it is affected by diet and hormones. | • Urea typically excreted by kidneys in urine o Also excreted in stool and sweat • Regulated by N-acetylglutamate o Stimulated by arginine |
Describe the basic function of the urea cycle including how it is affected by diet and hormones. | • Urea cycle fluctuates with diet and hormones o Low protein diet/acidosis _ _ urinary N excretion o Glucocorticoids and glucagon _ urea cycle enzymes |
What is the basic function of the alanine cycle? | • Production of alanine and lactate in the skeletal muscle o Glutamate →alanine in muscle • Alanine is transported to liver o Converted to pyruvate and urea |
What is the basic function of the alanine cycle? | • Energy dependent pathway o Not as efficient as Cori cycle • Transports N without forming ammonia o Toxicity of ammonia in bloodstream |
Compare and contrast the various nitrogen waste products. | 1. Creatinine- breakdown of creatine phosphate in muscle a. Produced at a constant rate in the body 2. Uric acis- heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen 3. Ammonia- compound of nitrogen and hydrogen |
What are the 2 cycles of nitrogen metabolism? | • Protein turnover a. Protein synthesis vs degradation • Nitrogen balance a. Nitrogen intake vs outpus |
What is the US RDA for protein intake? | • .8 g/kg of ideal body weight |
What factors decrease or increase protein requirements? | • Increase need- during increase synthesis or increase degragation • Decrease need- in liver, kidney and GI disease |
What are the pros and cons of soy protein? PRO | What are the pros and cons of soy protein? • Pro o Excellent AA profile o Bioavailability of minerals o Cholesterol lowering effect |
What are the pros and cons of soy protein? CON | • Con o Contains phytoestrogens o Quality o Pro soy vs anti soy • If a little bit of soy good is more better? |
What were the results of a year-long meat diet? | • Protein content 100 – 140 g/d • Fat content 200 – 300 g/d • Carbohydrate content 7 – 12 g/d • Calories 2000 – 3100/d • Mentally alert and physically active at end of year • Lost weight during 1st week and then maintained |
• Blood pressure was constant or decreased • Normal bowels except diarrhea if protein > 40% • Vitamin deficiencies did not appear • Acidity of urine 3X of mixed diets | • Daily calcium intake .05 - .15 g/d o Average calcium excretion .44 - .47 g/d • No evidence of kidney damage • No ill effects from prolonged use of an exclusive meat diet |
What is the difference between animal and plant protein? | • Sulfur content of animal protein o Lowers pH and must be buffered o Calcium is long-term buffer or potassium • Osteoporosis o Associated with _ animal protein intake in middle age o Associated with _ animal protein intake in elderly |
What is the difference between animal and plant protein? | • Bone health not determined by density alone o Bone strength, lean muscle mass, collagen • Animal protein _ N load more than plant protein • Animal protein and cancer?- china study • Supplement vs. replacement therapy |
Why We Get Fat Fat (Questions) | "If you want to lift yourself up, lift someone else up" |
What are 3 possible causes of obesity? | 1. Overeating 2. Sedentary lifestyle 3. Hormone imbalance |
Where do we store energy? | 1. Fat 2. Muscle 3. Liver 4. Gut |
What causes hunger? | • Under-eating and excessive physical activity |
Does exercise cause weight loss? Why or why not? | • Exercise is a major contributor to weight loss, but it does NOT cause it. |
Does exercise cause weight loss? Why or why not? | "The fact that more rigorous study designs(randomized trials) yielded very inconsistent results leads us to conjecture that the association between physical activity and weight change is more complex than judged from retrospective, cross-sectional studies |
Compare and contrast “balanced” underfeeding studies and a protein sparing modified fast. | See notes |
How could weight gain protect us from diabetes? (slide 156?) | |
Is ketosis dangerous? Why or why not? | see notes |
What are 5 possible epidemics behind the obesity epidemic? | 1. Insulin resistance 2. Leptin resistance 3. Reactive hypoglycemia 4. Liver stagnation 5. Stress |
What are 5 habits of healthy eaters. | 1. Diets don’t work 2. Don’t be scared of fat 3. Be scared of sugar 4. Buy food, not nutrients 5. Develop a relationship |
Questions from the book Why We Get Fat | See notes |
Name 3 side effects of carbohydrate withdrawal. (Carbohydrate withdrawal = “keto-adaptation”) | 1. Frequent urination 2. Fatigue and dizziness 3. Reactive hypoglycemia |