26 - Carbohydrates, Lipids and Proteins Flashcards Preview

GI and Renal Exam 2 > 26 - Carbohydrates, Lipids and Proteins > Flashcards

Flashcards in 26 - Carbohydrates, Lipids and Proteins Deck (40):
1

What percentage of premature deaths are caused by behavioral patterns?

40%

Obesity, tobacco, alcohol, etc.
Nutrition and health is important

2

What is the difference of fat content in previous times, western and Mediterranean diets

- We have a higher fat content than previous times (pre-agricultural)
- We have lower fat content than the Mediterranean diet however
- The Mediterranean diet has less saturdated fat which is the bad fat, so it is still better

3

What are we currently using for a food pyramid?

"My plate"

4

What are the dietary guidelines for Americans?

Science-based advice
- Promote health
- Reduce risk for chronic diseases
- Diet and physical activity

5

What are the 2010 American Dietary Guidelines?

- Balance calories/physical activity to manage weight
- ↑ fruits, vegetables, beans, and nuts
- ↑ whole grains, fat-free and low-fat dairy products
- ↑ fish and seafood
- ↓sodium, saturated fats, trans fats, cholesterol, added sugars, and refined grains

6

Describe food as energy

- Basic Fuels – Carbohydrate, Fats, Proteins (and ethanol)
- Fed state (storage of fat, glucose utilized, protein used)
- Non fed state (uses endogenous sources, maintain glucose, used stored glycogen, use stored protein and fat to produce glucose)
- Starvation (metabolic changes for alternative fuels)

7

Describe carbohydrates in the diet

- Organic compounds
- Molar ratio of C:H:O as 1:2:1
- 45-65% of daily energy
- 1 gram = 4 kcal
- Stored in liver & muscle as glycogen

8

Describe the difference between simple and complex carbohydrates

Simple ("sugar")
- monosaccharides (one sugar unit)
- disaccharides (2 sugar units)

Complex
- Multiple units of mono- and disaccharides can be joined together to form oligo- (10) (complex CHOs).
- Starch, glycogen, and fiber are examples of polysaccharides

9

What is the glycemic index?

- Glycemic index is a system to quantify the glucose response to CHO-containing food
- Glycemic index is defined as the area under the curve for the increase in blood glucose during the 2 hours following ingestion of 50g of food, as compared with ingestion of 50g of reference food (either glucose or white bread).

10

Describe high and low glycemic index foods

A food with a low glycemic index are usually more slowly digested, absorbed, and metabolized and will result in a smaller rise in blood glucose (and insulin) than one with a higher glycemic index.

The more manufactured or processed the food is, the higher the glycemic index

11

What happens to the reward center in the brain following a high glycemic food?

- Higher glycemic foods stimulate the reward center in the brain
- It stays stimulated for hours after
- May influence next meal choice as well

12

What are the potential clinical effects of high glycemic index dietary carbohydrates?

- Reduced satiety and more rapid return of hunger
- Increased prevalence of obesity
- Increased risk of type 2 diabetes (increased insulin resistance)
- Increased risk of coronary heart disease (high glucose, high insolin, high triglycerides, low HDL, small LDL, high oxidative stress, inflammatory cytokines and C-reactive protein)

13

Describe hyperglycemia in response to stress

- Stress hyperglycemia – elevated blood glucose in response to stress or illness
- ↑ stress hormones; ↑ production of cytokines; all oppose insulin
- Also leads to ↑ protein breakdown and ↑ fatty acid oxidation

Treatment response is decreased when blood sugars are high, so now we treat stress-induced hyperglycemia in the hospital

14

Describe high fructose corn syrup and fructose

***** KNOW THIS *****

HFCS
- In many foods/sweetened beverages
- HFCS is actually more similar to sucrose (table sugar) than to fructose
- HFCS is 50/50 of fructose and glucose)

Fructose
- Fructose absorption facilitated by glucose and other monosaccharides
- Excess fructose consumption can lead to gastric distress/diarrhea
- Fructose may impact hormone levels, satiety, & food consumption
- Type of sweetener has changed, but amount of fructose in diet has remained constant

15

Describe the studies on FRUCTOSE (not HFCS)

- Higher intake decreases LDL particle size in overweight children
- Increases de novo lipogenesis compared with glucose
- Increased fructose consumption is associated with fibrosis severity in patients with non-alcoholic fatty liver disease
- Increased serum uric acid – Cardiorenal
- Promotes chronic low level inflammation in young men
- However, many studies use a fructose:glucose ratio well above 1.0 or study fructose by itself (not as part of solid food)
- Overall very weak evidence that HFCS uniquely contributes to overweight/obesity

16

What are the types of dietary fiber?

Soluble
- Oats, legumes, vegetables, fruit, Metamucil
- Slows gastric emptying (may increase insulin sensitivity); increases gastrointestinal bulk; helps lower LDL cholesterol by interfering with cholesterol absorption

Insoluble
- Whole grains, bran, legumes, vegetables, fruit
- Increases water in GI tract; speeds colon emptying

Both
- Provides substrate for short chain fatty acid synthesis by colon microbiota

17

Describe the composition of whole grains

- Bran
- Endosperm
- Germ

During processing, bran and germ are removed – removing fiber, vitamins, minerals, antioxidants, healthy fats – leaving essentially the carbohydrates and proteins

Sometimes food manufacturers will enrich the product (add the nutrients back in), although it’s still healthiest to received the nutrients in the natural form

18

What is the role of fiber in clinical nutrition?

- Western diet – inadequate fiber (↑ fast food, ↑ processed foods, ↓ fruit/vegetable intake)
- No disease/syndrome for fiber-deficient diet (just constipation)
- Slows gastrointestinal transit time
- Decreases lipoprotein concentration in blood
- May lower all-cause and CVD mortality
- May decrease risk of colorectal carcinomas & adenomas

19

What are the benefits of fat?

- Provide texture, aroma, flavor to foods
- Phospholipids and cholesterol are structural materials of cellular membranes that provide the starting materials for other molecules
- Help in fat-soluble vitamin absorption
- Insulate, cushion (protect), lubricate
- Provides energy

20

How does fat provide energy?

- Adipose tissue can be broken down for energy
- Excess energy as CHOs or protein can be converted to fatty acids by liver and stored as triglycerides

21

Describe fat as part of the diet

- Insoluble in water
- High energy (9 kcal/g)
- Component of biological membranes
- Important for development
- Source of critical metabolic products (Inflammatory mediators, gene regulators, substances that resolve inflammatory responses and regulate lipid metabolism)

22

What are the types of fatty acids?

Saturated
- Meat, dairy products, coconut, palm, palm kernel oils, cocoa butter

Monosaturated
- Olive oil, avocado, canola oil

Polyunsaturated
- Corn, soy, sunflower, safflower oils

Polyunsaturated
- Oily ocean fish, flax seed oil, 10% in canola and soy oils

Partially hydrogenated polyunsaturated ω6 (Trans fats)
- Frying and baking oils and margarine

23

What are the health effects of each type of fatty acid?

Long-Chain Saturated
- Risk of CVD, ↑ LDL

Monounsaturated
- May ↓ LDL, cardioprotective

Polyunsaturated (N6) (ω6)
- Essential, ω6:ω3 important; some ↑ inflammatory cytokines

Polyunsaturated (N3) (ω3)
- Essential, ↓ TGs, cardioprotective, brain health?

Partially hydrogenated polyunsaturated ω6 (Trans fats)
- Most detrimental to health, ↑ LDL, ↓ HDL, ↑ inflammatory cytokines

24

What are the recommendations for fat intake?

Total fat
- 20-36 g

Long-chain saturated
- Minimized

Polyunsaturated
- 12-17 g (19-50 years old)
- 11-14 g (51-70 years old)

Partially hydrogenated polyunsaturated (trans fat)
- Minimized

25

What are the results of deficiency of essential fatty acids?

- Largely non-existent in normal population (7% of total energy intake)
- Deficiency documented in 70s in patients on parenteral nutrition (PN)
- Linoleic (dry skin, rash, increased infection, impaired wound healing, decreased immune function)
- α-Linolenic (less recognized, neurologic abnormalities, numbness, parasthesia, blurred vision, difficulty walking)

26

What are the potential benefits of omega 3s?

Autoimmune disorders
- Psoriasis
- Rheumatoid arthritis
- Asthma
- Multiple sclerosis
- Type 1 diabetes

Others
- CHD
- Depression
- Dementia

Don't need to memorize

27

Describe trans fatty acids

- Small amounts occur naturally (dairy)
- Produced during hydrogenation process
- Decrease rancidity/increase shelf life
- Labeling – allowed to list 0g if product contains

28

Describe animal, plant and hydrogenated fats

Animal fats – saturated; solid at room temperature

Plant fats – unsaturated; liquid at room temperature

Hydrogenation – converts unsaturated bonds into saturated

29

Describe the difference between cis and trans fat

Cis – natural unsaturated fatty acids (kinks)

Trans – no kinks, making it structurally similar to saturated fatty acids

30

Describe the regulation of artificial trans fats

June 16, 2015: FDA finalized decision to ban artificial trans fat

Mandated in 2018 - May prevent 20,000 heart attacks & 7,000 coronary deaths per year (CDC)

31

What are the physiological effects of consuming excess dietary trans fats?

- Dyslipidemia
- Abdominal fat deposition in primates
- Systemic inflammation (high interleukin 6, TNF alpha, C-reactive protein)
- Endothelial dysfunction
- Diabetes mellitus?
- Membrane properties

32

Describe the dyslipidemia that may result from trans fat

High LDL, high HDL, high triglycerides, high lipoprotein(a)

LDL particle sizedecrease (more atherogenic)

33

Describe the fat distribution when consuming trans fat

The diets produced weight gains of 1.8 and 7% respectively, and a higher proportion of the fat gain was deposited intra abdominally in the trans fat fed group.

34

Describe proteins

Composed of amino acids
- Building blocks of protein (20)
- Nutritionally essential, nonessential, conditionally essential
- Body degrades its own protein if essential amino acids are lacking
- Functionally all are essential
- Not “stored”

35

What are the functions of proteins

- Growth, maintenance, and movement
- Enzymes
- Hormones
- Immunity
- Regulators of gene transcription and translation
- Fluid and electrolyte balance
- Acid-base balance
- Transportation and storage

36

Describe the quality considerations in vegetarian/vegan diets

- May be more practical to design a lower calorie diet with animal protein than with plant protein
- Need to also consider micronutrients
- May impact weight control, reduce chronic disease, improve gut microbiome

Example
- 3oz lean beef = 160 kcal (23 g protein)
- 6 Tbsp peanut butter = 500 kcals (24 g protein)

37

How do you optimize nitrogen-energy relationships

- Loss of body protein – disability and death
- Cannot store excess amino acids; N is eliminated in urine
- Critically ill have accelerated protein loss demands greater energy and protein intake (1.5g/kg/day)
- Patients with burns/multiple trauma (2g/kg/day) - VERY high

38

Describe the risks of losing too much protein

- Too much protein can result in pre-renal azotemia
- Increases burden to kidney due to high demands for excretion
- Kidney stones, osteoporosis

39

What are the physiological effects of increasing protein intake?

High calcium, uric acid and citrate in the urine

40

What are the hypothesized effects of the acid-base state in the modern Western diet?

- Hypothesized that modern Western diet (↓fruits/vegetables; ↑animal products) increases non-metabolizable anions leading to low-grade metabolic acidosis
- Kidney compensates by removing non-metabolizable anions, conserves citrate, and increases excretion of ammonium, lowering urine pH – ↑ risk for uric acid stones
- Metabolic acidosis over time may lead to ↑ risk of insulin resistance, diabetes, hypertension, cardiovascular disease, and chronic kidney failure