Nutrition lecture objectives

Define Calorie

the amount of heat energy needed to raise the temperature of 1 gram of water through 1 °C

Name 3 ways to know how many calories are in a food

Bomb Calorimeter (raises temperature of surrounding water when food is burned completely - energy is measured by this temperature)

Nutrition Facts label (required by FDA)

Daily value (simplified way to determine how nutrients compare to needs)

How to interpret a nutrition facts label.

Start off with serving size and compare to your needs.

Identify energy dense foods

Contain more calories in relation to total portion.

ex: donut

Identify nutrient dense foods

Contain more nutrients in relation to total portion.

ex: strawberry

Define macronutrient

nutrients needed in large amounts, provides energy when digested

Name all 4 macronutrients

carbohydrates, lipids (fat), protein, ethanol (alcohol)

Role/function of mouth

tastes, chews food into manageable pieces, mix with saliva, moisten, some digestion (CHO), swallow

Role/function of esophagus

move food via peristalsis, muscles propel food through it

Role/function of stomach

hold food, expose to gastric (stomach) acid, smash food,

Role/function of small intestine

(duodenum, jejunum, ileum) break down food into smallest parts, absorb molecules into blood stream going to liver

Role/function of large intestine/colon

reabsorb water, excrete feces, home for bacteria

Describe the principle of energy balance

comparison of energy input to output

How can a positive energy balance lead to changes in weight

intake > output, gain weight

How can a negative energy balance lead to changes in weight

intake < output, loose weight

Name ways that appetite is regulated in the cephalic phase

determines food to eat based on texture, color, temperature, smell, taste, based on experiences

Name ways that appetite is regulated in the gastric/intestinal phases

stomach and intestines signal brain when to start/stop eating

start eating: hormone glycogen

stop eating: stretch receptors

Identify at least 4 triggers for humans to consume more calories than needed.

emotion/stress, routine/time of day, amount of food served, availability

Name foods that contain carbohydrates.

sugar (high fructose corn syrup, honey, agave nectar)

desserts (cookies, candies, cakes)

fruit

dairy (milk and yogurt, kefir)

Grains (rice, wheat, barley, oats, corn, buckwheat, rye, quinoa, includes flour, breads & flat breads, pastas made from grains)

Starchy vegetables (potatoes, beans, peas, yuca/cassava, taro)

carbohydrates

Identify the 1 primary function of carbohydrates.

energy

Classify simple carbohydrates when given a description of the structure.

made of 1 (monosaccharides) or 2 (disaccharides) sugar units

Classify complex carbohydrates when given a description of the structure.

Made of 3 or more sugar units (polysaccharides) including starch and fiber

example of a simple carbohydrate (sugars)

monosaccharides: glucose, fructose, galactose

disaccharides:

sucrose: glucose + fructose = table sugar (milk)

lactose: glucose + galactose =milk

maltose: glucose + glucose = in malt beverages

example of a complex carbohydrate (polysaccharides)

Plants: Amylose & amylopectin (AKA, starch)

Animals: glycogen

Fiber

Calculate the amount of simple & complex carbohydrates provided in a food using the Nutrition Facts Label

total carbohydrates - dietary fiber - sugars = starch

ex: 37 grams total CHO - 4 g fiber - 12 g sugars = 21 grams starch

identify lactose monosaccharide units and what breaks it down

unit: glucose + galactose

breaks down: lactase

identify maltose monosaccharide units and what breaks it down

unit: glucose + glucose

breaks down: maltase

identify sucrose monosaccharide units and what breaks it down

unit: glucose + fructose

breaks down: sucrase

Track the digestion of carbohydrates through the mouth

Saliva moistens; salivary amylase breaks bonds between monosaccharides

Track the digestion of carbohydrates through the esophagus

Moves food to stomach

Track the digestion of carbohydrates through the stomach

carbohydrate digestion stops because of stomach acid

Track the digestion of carbohydrates through the small intestine

pancreatic amylase breaks carbohydrates down further

Villi make sucrase, maltase, lactase

Absorbs monosaccharides and put them into the blood

Track the digestion of carbohydrates through the colon/large intestine.

only fiber should be present

if lactose is indigested, ferments in colon (lactose intolerance symptoms)

Describe the substrates, products, and site of action for salivary amylase

substrate: starch

product: smaller starch fragments

site of action: mouth

Describe the substrates, products, and site of action for pancreatic amylase

substrate: starch

product: maltose + small polysaccharides

site of action: small intestine

Describe the substrates, products, and site of action for lactase

substrate: lactose

product: glucose + galactose

site of action: small intestine

Describe the substrates, products, and site of action for sucrase

substrate: sucrose

product: glucose + fructose

site of action: small intestine

Describe the substrates, products, and site of action for maltase

substrate: maltose

product: glucose + glucose

site of action: small intestine

Define the 1 primary function of the liver.

nutrient processing

Identify the cause for lactose intolerance.

depends on genetic descent, age, unable to regulate dairy

Identify the 3 symptoms for lactose intolerance.

gas, abdominal pain and bloating, diarrhea

Identify the 2 treatments for lactose intolerance.

avoid lactose, take lactose enzyme supplements

List the 2 functions of the pancreas.

Exocrine function: create digestive enzymes like pancreatic amylase

Endocrine function: create insulin in the beta cells in response to high blood

Describe how insulin functions to get glucose into the cells.

- Glucose transporters in the cell membrane need to be opened for glucose to enter cell. - Insulin is the "key" that unlocks the "doors" of the transporters.

- One insulin opens the transporters glucose enters the cell from bloodstream to be used for energy, lowering blood glucose levels

- insulin production increases based on blood - glucose levels ensuring levels are at a normal range

Identify the 3 possible uses for glucose once it has entered the cells.

used for energy

energy storage - glycogen

fat storage

Define the function of glycogen.

storage form of carbohydrates in animals, but big bulky molecules that are not very efficient

readily available source of glucose when needed for energy

Describe the prevalence of diabetes mellitus

very common, 30.3 Million cases in U.S.

Describe the prevalence of prediabetes

1/3 of people have prediabetes (in U.S.?)

Describe the negative health effects of hyperglycemia

(like sandpaper) damages nerves, can't feel feet, blindness, lower leg amputations, kidney failure

Recognize the pathophysiology and treatments of type 1 diabetes.

(insulin defficiency)

cause: autoimmune disease where pancreatic cells that produce insulin are destroyed

triggers: genetics, environment, infections

- glucose cannot get into cells because no insulin is produced

treatment: give insulin when consuming carbohydrates (match dos with amount of carbohydrates eaten)

Recognize the pathophysiology and treatments of type 2 diabetes.

(insulin resistance)

cause: insulin is produced but cells are unresponsive, obesity

- eventually a little insulin can get through, but need to control the amount of carbs consumed so blood glucose levels do not get out of control

treatment: medication to increase insulin production/make cells more sensitive to insulin, control amount of carbs consumed, regulate diet to keep glucose under control

Diagnose hypoglycemia based on symptoms.

irritability, dizziness, weakness, fainting, coma, death

Describe how glucagon functions to raise blood glucose levels.

tells liver to break down glycogen and release into blood stream

Determine the effects on blood glucose caused by carbohydrate

raise glucose

Determine the effects on blood glucose caused by protein and fat

minimal effect

Determine the effects on blood glucose caused by mixed meals

fiber, fat protein slow digestion, fructose and galactose must be converted into glucose before raising blood sugar

Define the glycemic index

a measure of how a particular food affects blood glucose levels

how the glycemic index of a food is determined

feeding people 50 grams of carbohydrates in a test food and tracking blood-glucose levels

Estimate glycemic index based on the 5 factors that will lower the glycemic index of a food

5 factors: less processing, less sugar (added), higher protein content (slow digestion), higher fat content, (slow digestion) higher fiber content (delays glucose into blood stream)

Define the two types of fiber

soluble: dissolves in water (pectin, gums, carrageen, oats, beans)

insoluble: does not dissolve in water (cellulose, hemicellulose, lignin, cell walls of plants)

health benefits for soluble fiber

decrease blood cholesterol and glucose

health benefits for insoluble fiber

helps with bowel movements, helpful bacteria in gut

whole grains

contains bran (fiber B and vitamins), endosperm, and germ included

enriched grains

bran removed (fiber lost), B vitamins added back after processing but not fiber

Identify sugars from an ingredients list.

Sucrose

Sugar cane and sugar beets

White table sugar

Brown sugar

Turbinado sugar or "Sugar in the Raw"

Confectioner's or powdered sugar

Fructose and glucose

Corn syrup, high-fructose corn syrup, corn syrup solids

Honey, Agave nectare

Edible syrups like molasses, maple syrup, pancake syrup

fruit nectars or fruit juice concentrates

Coconut sugar or date sugar

List 3 reasons sugars are discouraged.

over-consumed, can lead to tooth decay, low nutrient density balance

Name the top category of foods that contributes the most added sugars to the American diet.

sugar sweetened drinks

Describe the recommendations for sugar intake per the Institute of Medicine

Suggests a maximum of 10% of energy as sugars(2) If eating all food group recommendations, < 7% kcal available

Describe the recommendations for sugar intake per the American Heart Association.

Limit 100 kcal/day for women, 150 kcal/day for men (1/2 of discretionary calories)

Calculate calories and percent of calories from added sugars when provided a Nutrition Facts label.

added calories x 4 = calories from added sugar

calories from sugar/total daily calorie intake = percent of total calories

Name 4 negative outcomes caused by excessive intake of sugars.

tooth decay, excessive calorie intake, less intake of nutrients, possible liver damage

Identify sugar alcohols

mannitol, sorbitol, xylitol, lactitol, isomalt, maltitol and hydrogenated starch hydrolysates (HSH).

in candy, breath mints, gum, toothpaste

Describe the reason that sugar alcohols cause diarrhea

poorly absorbed in GI tract, causing disturbance

Define the Acceptable Daily Intake.

Estimated amount per kg of body weight a person can consume daily for a lifetime without any adverse effects

List 4 FDA-approved nonnutritive sweeteners.

1. Saccharin (Sweet-N-Low)

2. Aspartame (Equal or Nutrasweet)

3. Sucralose (Splenda)

4. Stevia

Describe why nonnutritive sweeteners have "no" calories.

only a tiny amount is needed

Defend the safety of nonnutritive sweeteners in the food supply.

FDA sweeteners have undergone safety testing

Describe 3 reasons that people who use nonnutritive sweeteners may weigh more than those who do not.

Trying to lose weight (leads to people craving sweet food)

Taste dependence

Changes to gut bacteria

Understand who may benefit from use of nonnutritive sweeteners.

trying to reduce sugar intake while still consuming sweet things, people with diabetes, those aiming to prevent dental cavities

fats

lipids that are solid at room temperature

oils

lipids that are liquid at room temperature

State 4 purposes of lipids in the diet or human body.

energy

energy storage

insulation and protection

help with absorption of fat soluble vitamins

Name the one most important contributor of lipid to the American diet.

triglycerides: make majority of dietary and stored fat

saturated fatty acid

no double bonds, solid at room temperature,

food sources: full-fat dairy (whole milk, cheese, cream), meat, coconut oil, palm and palm kernel oils

monounsaturated fatty acid

one double bond, liquid at room temperature

food sources: olive oil, canola oil peanut oil, avocados

polyunsaturated fats

more than one double bond

food sources; safflower oil, grapeseed oil, sunflower seed oil, soybean oil

Omega-6 fatty acid

(linoleic acid), PUFA

food sources: vegetable oil, nuts

omega-3 fatty acids

alpha - linoleic acid, ALA, DHA, EPA

Food sources: flax seed oil (ALA), walnuts (ALA), fish oil(DHA & EPA)

Trans Fatty Acids

Created through process of hydrogenation

food sources: previously in processed foods, banned from most foods

Name the two essential fatty acids

linoleic acid (omega-6) and alpha-linolenic acid (omega-3)

Describe the process and the purpose of hydrogenation.

process: Unsaturated fat gains hydrogens, becomes "partially hydrogenated"

purpose: reduce saturated fat content of foods (related to heart disease), mimic chemical properties of saturated fat, lengthen shelf life of foods

Calculate calories provided by fat.

grams of fat x 9 = calories from fat

calories from fat/total calories = percent calories from fat

Describe the purposes of bile in fat digestion.

emulsifies fat (separate into droplets)

Describe the purposes of pancreatic lipase in fat digestion.

digestion (breaks apart triglycerides when emulsified by bile)

Describe how soluble fiber works to decrease blood cholesterol levels

soluble bile binds to intestines, preventing reabsorption

liver uses cholesterol to make new bile

(process removes cholesterol from the body, lowering blood cholesterol levels)

Know the mechanism of the weight loss drug orlistat and describe its safety

mechanism: inhibits pancreatic lipase, preventing breakdown and absorption of triglycerides

safety considerations: can cause gastrointestinal side affects (olily stools, diarrhea)

Identify food sources of cholesterol.

animal products (ie: meats, cheese, eggs, milk, liver)

LDL cholesterol

bad. low density lipoprotein.

carries protein to cells low protein, high fat "lousy cholesterol"

HDL cholesterol

good. high density lipoprotein.

picks up cholesterol in blood stream and transports back to liver, high protein, low fat "happy cholesterol"

Place in correct order the steps of the development of atherosclerosis

LDL can be broken down ("oxidized") and cause damage

White blood cells take up this oxidized cells and become foam cells

foam cells form fatty streak

fatty streaks grow into plaque

plaque blocks blood flow leading to heart attack/stroke