exam 2 nutrition
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- What is the general dietary strategy to prevent or treat diabetes?
- Regular, balanced meals that miminize the glycemic response Eating a diet high in complex carbohydrates is best (more fiber)
- How is that generally implemented
- Use glycemic index vs. restricting sucrose
- specific dietary recommendations for low Glycemic Index Diet
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o High in soluble fiber à slows down glucose absorption
o Distinguishes between starches (higher amylose vs. amylopectin content) - specific dietary recommendations for sucrose intake?
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o Moderate intake with meals
o Ones not highlited
⬢ >30% of energy may decrease insulin sensitivity, exacerbate triglyceride increase (fructose content)
⬢ Non-nutritive sweeteners helpful, fructose is not better - specific dietary recommendations for blood lipids?
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Limit total fat intake up to 35%, reduce simple carbs
Monounsaturated fats are associated with favorable levels of blood glucose, lower triglycerides (olive, canola oils)
Reduces body weight - specific dietary recommendations for alcohol?
- Moderate alcohol intake
- Other dietary recommendations
- Add fermented foods and foods with high acidity to your meal
- What are the lifestyle recommendations
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Moderate aerobic physical activity
Weight maintenance - How can type 2 diabetes remediate?
- ⬢ Cases linked to obesity (type 2) can remediate with healthy weight
- Name 4 complications of uncontrolled diabetes
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Cardiovascular disease
Retinopathy / cataracts
Nephropathy
Neuropathy - What is gestational diabetes
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Occurs during pregnancy, disappears after delivery
Hormones block action of mother's insulin in her body - what are the risks
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Increases risk for later development of type 2 diabetes in mother and infant
Infant may be overweight at birth complicating delivery (macrosomia)
Up to 20% could have serious physical abnormality - What is hypoglycemia
- Abnormally low blood glucose levels
- Distinguish between reactive and fasting types.
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Reactive Hypoglycemia
ï® Occurs 2-4 hrs after a meal, especially high simple sugar intake
ï® May be due to overproduction of insulin by pancreas OR environ-mental factors such as stress, exercise or alcohol consumption
Fasting Hypoglycemia
ï® Blood sugar falls to low concen-trations after fasting for 8 hrs–1 day
ï® Rare; usually caused by pancreatic disease - List the 3 strategies to prevent and treat it
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Eat smaller, more frequent meals to help maintain blood sugar levels
Eat low glycemic index carbohydrates - complex with focus on soluble fiber
Moderate caffeine and alcohol intake - Which lipid makes up 95% of fats in food and in the body
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⬢ Triglycerides
o Chief lipids - what is the chemical composition
- Composed of 3 fatty acids
- What factor affects the solubility of fatty acids
- Chain length determines the solubility in water, chains may be 4-24 carbons long. The longer the chain the less soluble they are
- many carbons do long-chain fats have
- Long chain fats are 12-24 carbons in length
- How do fatty acids differ
- The number of carbon atoms and the number of double bonds
- are the differences between saturated and unsaturated fatty acids (chemical structure, form, dietary sources)?
- Saturated fats do not have double bonds and they have more hydrogen
- What are the two major types of unsaturated fatty acids?
- Monounsaturated and polyunsaturated
- What are their main dietary sources
- Mono- is found mostly in vegetable oils as olive, canola, and peanut. Poly- is found in nuts vegetable oils, and fatty fish
- How is the form of a lipid affected at the points of unsaturation (site of double bonds)
- the points of unsaturation enable fatty acid flexibility
- What are the two essential fatty acids (common and chemical name)
- Omega-3, and Omega-6, are the common names and the chemical names are arichidonic acids(omega 6) and Eicosapentaenoic (omega 3) acids
- What compounds does the body produce using these essential fatty acids
- Eicosanoids-Hormone like compounds that regulate physiological processes (may or may not be inflammatory)
- Describe the difference between omega-3 and omega-6 fatty acids in terms of eicosanoid production (product name and health effects) and dietary sources
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Omega 6 produces archidonic acid and omega 3 produces (DHA and EPA)
Omega 6 pairs with lineoleic acid
Omega 3 pairs with lineolenic acid
Omega 6 is inflammatory and omega 3 is not
Omega 3 is found in fish/fish oils, flaxseeds, walnuts, etc.
Omega 6 is found in sufflower, sunflower, corn, meat, restaurant and processed foods - What is the benefit of conjugated linoleic acid (an omega-6)
- May protect against certain cancers
- Name the major dietary oil sources of the following fatty acids: saturated, monounsaturated, omega-3, and omega-6.
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Saturated fatty acids- coconut oil, butter fat, palm kernel oil, beef fat, lard
Monounsaturated- monounsaturated fats: olive, canola, peanut oils
Omega-3- flax, canola, soybean oils
Omega 6- safflower, sunflower, corn, soybean oils - What two factors about fatty acids influences food characteristics⬦describe them
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o Firmness
 More strurated the more firm
 Shorter the chain the softer the fat
o Stability
 The more double bonds the more fluidity the fat has
 The more double bonds the greater susceptibility to oxidation (spoilage, reancidity) - . What are double bonds prone to?
- Double bonds are prone to oxidation
- Which type of oil has more double bonds
- Omega 3 has more double bonds or points of unsaturation
- Define oxidation
- Oxidation: means loss of a hydrogen atom or electrons and gain of one or more oxygen atoms generated by
- What is rancidity
- ⬢ Rancidity: result of oxidation due to exposure to air, high heat, light
- What foods are the most susceptible
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o Highly polyunsaturated oils
o Deep fried foods
o Powdered eggs powdered milk
o Fatty fish - Why were solid fats used in food processing in the past
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o Solid fats historically preferable
 More stable ïƒ longer shelf life
 More useful… - What is the downside for food processors when liquid oils are used in food processing? What two methods can prevent that?
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Processors prevent rancidity by adding natural or synthetic antioxidants
Hydrogenation: the process of adding hydrogen to unsaturated fat to make it more solid and more resistant to chemical change - Describe the process and name the product of hydrogenation
- Hydrogenation: the process of adding hydrogen to unsaturated fat to make it more solid and more resistant to chemical change
- In what ways do many of the fatty acids in the oil change, and what is the health effect?
- Trans fats are created in the process. The chemical structure of fats are altered from the normal cis form to the trans form changes the shape and affects its ability to perform its function in the body. Trans fats are similar to saturated fat in shape and health effect
- How are phospholipids chemically different from triglycerides? Name a common phospholipid. What are two functions of phospholipids?
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• Phospholipids are important components of all cell membranes
o Acts as emulsifiers in the body and in food
o Mix with both fat and water, can break fat globules into small droplets
• Triglycerides
o Chief lipids
 The form of 95% of all lipids in foods and in the body including fats and oils
Composed of 3 fatty
39. What’s a common sterol? What is 90% of it used for in the body?
o Lipids with a multiple ringed structure such as…
o Structural part of cell membranes (90%) - What’s a common sterol? What is 90% of it used for in the body?
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o Lipids with a multiple ringed structure such as…
o Structural part of cell membranes (90%)
 Also used to make bile, sex hormones, as well as vitamin D - Where does 2/3 of our cholesterol requirement come from?
- Our livers make 2/3 of our requirements
- ? Which foods contain cholesterol
- Only animal foods contain Cholesterol
- Where is fat digested and absorbed? Name the hormone, emulsifier, and digestive enzymes involved.
- Small intestine – CCK signals gallbladder to release bile to emulsify the fat so it can be digested by pancreatic and intestinal lipases
- What is recycled in the process called enterohepatic circulation
- Enterohepatic circulation of bile: most of the bile is released into the small intestine is reabsorbed and sent back to the liver to be reused. Some bile trapped be fiber is excreted
- How are short-chain fats, medium-chain fats, and glycerol absorbed? What happens to long-chain fats? How are they carried?
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⬢ Glycerol short and medium chain fatty acids are absorbed directly into the blood
⬢ Monoglycerides and long chain fatty acids merge into mucelles absorbed and reassembled into the new TRG chlyromicrons - Define all four lipoproteins and compare their composition in regard to protein, cholesterol, and triglyceride content. What does density refer to?
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LDL cholesterol
⬢ Keeps cholesterol in circulation (50% cholesterol)
⬢ Carries it to bloodstream from liver
⬢ Composed of more fats, subject to oxidation
HDL cholesterol
⬢ Substantial pickup of cholesterol to escort back to liver for breakdown, excretion
VLDL- carries fats that are synthesized
Makes fats available to body cells via enzyme action
⬢ chlyromicrons: transport newly digested fat moestly triglycerides from intestine through lymph and blood
o Density refers to protein content - What enzyme hydrolyzes triglycerides from lipoproteins in the bloodstream? What enzyme releases triglycerides from the cell?
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⬢ Fat is release by hormone sensitice lipase in adipose cells
⬢ Lipoprotein lipase
o Hydrolyzes triglycerides from lipoproteins glycerol, fatty acids, monoglycerides
Enter adipose cells reassembled stored as triglycerides - What’s the main purpose of fats in the body?
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o Provide concentrated source of energy
o Serve as an energy source - 47. If a person is in a fasting state resulting in insufficient carbohydrate intake, can fatty acids be converted to glucose to provide energy for the brain and red blood cells? What is the immediate consequence of that scenario?
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a. Carbohydrates in blood and glycogen get used first
b. Lean tissue (protein) breaks down to provide glucose
Fat gets released from cells glycerol converts directly to glucose - Describe the three phases of atherosclerosis. What factors can cause injury to vessel walls? What is the major component of plaque at the site of injury?
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-initial phase: artery wall is damaged inflammatory response, Microphages, smooth muscle cells gather LDL cholesterol is oxidized and embedded in vessels walls
-progression phase: plaque thickens as layers of components are deposited
-Terminal phase: partial blockages can break through with surge in blood pressure platelets cover damaged areas, form clot
Factors: Oxidized lipids, elevated homocysteine, C-reactive proteins (along with smoking, pollutants, high blood pressure, etc⬦) - . Define elevated C-reactive protein and blood homocysteine levels as risk factors. What dietary factors can initiate these risk factors?
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⬢ C-reactive proteins
o Acute phase protein produced during inflammation
o Blood elevation could indicate ongoing arterial information
o Promoter as well as important predictive marker for future heart attack
⬢ Elevated Homocysteine levels
o Complete metabolism of methionine to cysteine requires adequate levels of certain B vitamins, particularly folate
o Inadequacy of folate can cause rises in blood levels of homocysteine injures artery walls
o High homocysteine levels are associated with CHD, as well as stroke and impairment of cognitive ability.
Not complete find the last part of the problem - List the three unmodifiable risk factors for heart disease. What are the modifiable risk factors?
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⬢ Unmodifiable
o Increasing age
o Family history
o Male gender
o Low birth rate (<5.5lbs)
⬢ Modifiable
o High blood pressure
o Diabetes
o Obesity
o Cigarette smoking
o Inactivity
o An atherogenic diet
o Elevated homocysteine - What four major dietary factors contribute to the ‘atherogenic diet’?
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⬢ High saturated fat increase LDL
⬢ High in simple sugars raises insulin output which raises triglycerides and LDL
⬢ Low in fruits, vegetables, and other complex carbs low antioxidants, fiber, nutrients
⬢ High in omega 6 and low in omega 3 fats more inflammatory - What common syndrome is a precursor to heart disease?
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⬢ Metabolic syndrome x
o Cluster of health⬦
o Overeating and inactivity - strategy 1
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⬢ Strategy 1
o Increase intake of antioxidants
⬢ Block free redical damage, reduce oxidation of LDL
⬢ Vit E, vit C, Selenium, beta-carotene, other phytochemicals
⬢ Benefits of fruits, vegetables, whole grains
o Fiber- soluble fiber reduces LDL cholesterol
o Minerals- help control blood pressure
o Antioxidants- protect lipids from oxidation helps prevent injury to vessles
o B vitamins- help prevent high Homocysteine levels
⬢ Need to know what the desirable numbers are and what the high numbers are for LDL, HDL, and Triglycerides - 2
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• Strategy 2
o Lowering LDL cholesterol
• How?
• Reducing total fats by…
• Trim fat off meat
• Choosing lower fat dairy
o Reducing saturated fats and trans fats ïƒ reducing animal fats and partially hydrogenated fats…why?
 More rigid membranes associated with cell malfunction
 High levels correlate with higher abdominal fat
 Possible association with inflammation - 3
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⬢ Strategy 3
o HDL cholesterol
o HDL levels correlate inversely with heart disease risk
o An acceptable total blood cholesterol reading may not be protective if⬦
o What about raising LDL
⬢ Lowers circulating LDL may block oxidation of LDL
o Factors that raise HDL
⬢ Avoid less than 20% FAT DIET
⬢ Lowering triglycerides
⬢ Regular sustained aerobic activity, weight training
⬢ Moderate alcohol consumption (1-2 drinks a day)
⬢ Also may prevent blood clots
⬢ What about dietary cholesterol?
⬢ Only found in animal foods
⬢ Only 1/3 of blood cholesterol comes from the diet
⬢ Limiting dietary cholesterol⬦