HUN1201 Mosing Midterm

Major purpose of dietary guidelines

to prevent chronic disease and promote health

Dietary guidelines

-published and revised by US Department of Agriculture and the Department of Health and Human Services

-provide helpful advice for making smart food choices

Observation that provides evidence that a person had good nutritional status is

normal weight to height ratio

Registered Clinical Dietitian

professional primarily responsible for application of nutrition science in a clinical practice settings

Public Health Dietitian

professional primarily responsible for application of nutrition science in a public health setting

Metabolism

sum of all of the body's chemical processes inside the cells of the nutrients that sustain life and health

Food change and transformation through a successive interrelated system

foods are transformed into simple substances that can be absorbed into the body and enters the metabolic pathways in the cell

Nutrients interact in the body to

regulate metabolic processes, to build and repair tissue, and to provide energy

Best source of nutrients

provided by a variety of foods (mixture of macro and micronutrients)

Primary nutritional function of the large intestine

absorption of water

Most digestion in the body takes place in

the small intestine specifically the duodenum

Exchange Lists for Meal Planning

-groups food that are equivalent in their macronutrient content

-specifically designed to have carb consistency for patients with diabetes

Food as it occurs naturally is

a mixture of chemical substances and nutrients

Nutrients released from food

remain unavailable to the body until they cross the intestinal wall and are transported to tissues for storage or immediate use

4 major functions in digestion and absorption

1. receives food

2. releases nutrients from food

3. delivers nutrients into the blood

4. excretes indigestible waste

Digestion

the first step in preparing food for use by the body

2 types of actions produced by digestion

1. muscular- chew the food into small particles

2. chemical- enzymes act on it

Muscles along the GI tract produce

-mixing motions assist in the breakdown of food materials

-rhythmic contractions propel the food mass forward along the tract

-valve control assists in moving the food forward at the appropriate rate for the digestive function

Ileocecal valve connects

Ilium and Cecum

Throughout the GI tract specific nerves

regulate muscle action

Interrelated network of nerves within the GI wall that extends from the esophagus to the anus

Intramural Nerve Plexus

Mastication

the action of biting, chewing, and breaking up ingested food into smaller particles

Mucus benefits

the lining of the stomach and intestine is protected from self-digestion by mucus

CCK- Cholecystokinin

hormone responsible for stimulating the gallbladder to contract and release bile

Salivary Glands (found in the mouth)

Parotid, Submandibular, and Sublingual Glands

Bile

-fluid made and released by the liver and stored in the gallbladder

-helps with digestion

-helps enzymes in your body to break down fats into fa, which can be taken into the body by the digestive tract

Intestinal Mucosa

the tissue that has the highest rate of protein turnover

Probiotic

living

Prebiotic

what probiotics act on

Phytochemical

plant chemical (luetine, beta-carotene, etc)

Food is digested chemically

through the combined action of a number of secretions (special cells in the mucosal lining of the GI tract and in adjacent accessory organs produce these secretions)

Enzymes

-end in -ase

-important type of metabolic chemical that is not used up in the reactions it causes

Primary function of macronutrients in the body

(carb, fat, protein) is to supply energy

Carbohydrate (CHO) Metabolism

glucose is the immediate energy source for all body cells

Fatty Acids

preferred fuel for the heart

Sources of Blood Glucose

-Carbohydrate Sources

1. dietary starches and sugars

2. glycogen stored in liver and muscle

3. products of carb metabolism such as lactic and pyruvic acid

-Noncarbohydrate sources

1. protein and fat provide indirect sources of glucose

2. formation of glucose from protein, glycerol, and carb metabolites is called gluconeogenesis

Monosaccharide

-smallest, simplest sugars that contain 6 carbon atoms

-classified as hexoses

Blood Glucose

-normal range of 70-120mg/dl

-when blood glucose levels begin to fall, stored glucose is released into the blood for use in meeting the energy needs of the brain and other cells

Nutrient that has protein-sparing effect

-carbs

-used for tissue building and repair

-need certain amount of carbs--> don't have that but instead mostly protein--> protein has, C, H, O, and N--> strip off N to use what body wanted was CHO--> not a healthy state

Glucose

sugar to which all other sugars are converted to during human metabolism

Carbohydrates

-nutrient group that provides the body with it's primary source of energy

-most essential

-burned as glucose

-stored as glycogen in muscle and liver

-easily stored for a long period of time

-pregnant women need more carbs and protein

-4 kcal/gram

-preferred type-complex

Hormonal controls for carbohydrate

-hormones directly and indirectly influence glucose metabolism and regulate blood glucose levels

-insulin- lowers blood glucose level

Starch that plants store for their own energy needs

become a source of fuel for humans who eat those plants (process of photosynthesis)

Quick Energy Foods

Carbs

Carbohydrate Classification

-smallest are simplest to absorb

-classified according to the number of basic sugar or saccharide units that make up their structure

-simple carbs- monosaccharides and disaccharides

-complex carbs- polysaccharides

Monosaccharides

-3 important in human nutrition

1. glucose

2. fructose

3. galactose

Disaccharides

-double sugars made up of 2 monosaccharides linked together

-3 of physiologic importance

1. sucrose- table sugar

2. lactose- milk sugar

3. maltose- grain sugar

Polysaccharides

-made up of many (poly) single glucose (saccharide) units

-complex coiled chains

-important energy-yielding polysaccharides

1. starch

2. glycogen

3. dextrins

Glycogen

-storage form of carbohydrate in animals

-made in liver cells and stored in relatively small amounts in the liver and muscle

Glycogen Reserves

-protect cells, especially brain cells, from depressed metabolic function and injury

-support urgent muscle responses as needed

-back up source of energy

Antiketogenic effect

-ketones are intermediate products of fat metabolism

-under extreme conditions when available carbs are inadequate to meet energy needs, fat is oxidized at excessive rates

-ketones accumulate and the result is ketoacidosis

-sufficient amounts of dietary carbs prevent damaging excess of ketones

Nutrition Science

-body of scientific knowledge related to nutritional requirements of human growth, maintenance, activity, and reproduction

-knowledge of the nutritional requirements for the body

Macronutrients

fat, CHO, protein

Micronutrients

vitamins, minerals

Water

-regulatory agent

-provides essential base for all metabolic processes

-percentage of body weight that consists of water in a person of normal body weight is approximately 50-65%

-men have more body water because they have more muscle

Recommended Nutrient Ratios (calories)

-Protein 10-35%

-CHO 45-65%

-Fat 20-30%

Functions of Food

-source of nutrients that the body requires

-plays a factor in satiety

Individual nutrients have specific functions

no nutrient ever works alone!

General Functions of Nutrients

-provide energy

-build and repair body tissue

-regulate metabolic processes that maintain homeostasis and sustain life

Fiber

-another form of CHO

-does not provide energy or calories

Fats

-body's alternate storage form of energy

-9 kcal/gram

-intake limited to 20-35% total kcal

-< 10% should be from saturated fat

Lipoproteins are produced

in the intestinal wall after the initial absorption of dietary lipids and liver for constant recirculation to and from cells

LDL

-low-density lipoprotein

-positively associated with cardiovascular disease

Amino Acids

-form basic building blocks of protein

-20 used to build body proteins

-9 essential amino acids- cannot be made by the body and must be supplied by food

-5 indispensable amino acids- can be made by the body in adequate amounts

-conditionally indispensable amino acids fall in between

Protein

nitrogen is a vital element in protein necessary for our body's structure (protein is 16% nitrogen)

Protein Balance

the steady state that exists between protein synthesis (anabolism) and protein breakdown (catabolism)

Complete Proteins

-animal foods

-contain all of the indispensable amino acids in the amounts and ratio needed to support protein synthesis

-includes eggs, milk, cheese, meat, poultry, and fish

Incomplete Proteins

-plant proteins

-supply less than the required amount of one or more indispensable amino acids or are missing an indispensable amino acid

Infections are

common in people who have inadequate protein intake because of insufficient quantity of antibodies

Low protein intake during pregnancy

increases risk of a low-birth weight infant

Primary function of proteins

-build, repair, and maintain body tissues

-provide energy if there is a shortage

Anabolism

-tissue building

-builds tissue through the synthesis of new protein

Tissue building nutrients

protein, minerals, and vitamins

Calcium and Phosphorous

build and repair bone

Iron builds

hemoglobin

Vitamin C

tissue synthesis and healthy skin

Vitamin A

-aids in vision in dim light

-fat-soluble (also D, E, K) heat stable

-pro-vitamin A- produce section

-pre-vitamin A- liver

Hormones

substances that serve as chemical messengers to help regulate and control enzyme activity

Nutrients involved in metabolic regulation and control

include minerals, vitamins, and water

Ideal Status

-nutrient intake neither deficient or an excess

-nutrient reserves at upper end of normal range and not used for daily use

Marginal or Borderline Status

-nutrient intake is minimal

-nutrient reserves are lacking

Overt Malnutrition

-nutrient intake insufficient

-reserves are depleted

-most vulnerable- those living in poverty, infants and children, pregnant women, elderly adults, and hospitalized patients and residents in long-term care facilities

Monitoring Well Being

-health measure of concern- nutrition, intake, body weight status, bone health, iron deficiency anemia, blood lipid levels

Guides have shifted from

preventing undernutrition to controlling chronic diseases related to overnutrition

RDA

reference for intake levels of essential nutrients to be adequate for most healthy people

Adequate Intake (AI)

suggest new beneficial effects of particular nutrients (i.e. calcium and vitamin D)

Upper Level (UL)

draws attention to dangers of inappropriately high intakes of specific nutrient (more is not better)

USDA MyPlate Goals

-increase intakes of fruits, vegetables, and whole grains

-balanced energy intake

-increase intake of vitamins, minerals, and fiber

decrease intakes of saturated fat, trans fats, and cholesterol

Saturated and Trans Fat

increase the risk of heart disease

Exchange List Food Guide

-meal planning tool for assisting persons with diabetes

-helpful in planning any diet such as weight reduction

Definition of Obesity Using Body Mass Index (kg/m2)

-measures the amount of muscle to fat

-Underweight:

1lb of body fat

3500 calories

Thermic Effect of Food (TEF)

-increment in energy expenditure above resting metabolic rate due to the cost of processing food for storage and use

-refers to the fact that digestion, absorption, and metabolism of food requires energy

Need for Body Fat

-some body fat is necessary for survival (men require 3%, women require 12%)

-reproductive capacity women require a body fat of 20% (initiation of menstruation occurs when the female body reaches a certain size, or more precisely, this critical proportion of body fat)

Body Types

-Ectomorphs- body type that is generally slender and fragile

-Mesomorphs- prominent muscle and bone development

-Endomorphs- soft, round physique with an accumulation of body fat

BMR

Basal Metabolic Rate- if you have a fever BMR goes up

Caloric values found in food composition tables

are determined by direct calorimetry

RMR

Resting Metabolic Rate- often measured instead of BMR because RMR is easier to measure

Beta-Carotene

-Provitamin form of Vitamin A found in plant pigments

-deficiency results in night blindness

-good sources are spinach, carrots, and sweet potatoes

Vitamin D was added to milk

to prevent rickets in children and osteomalacia in adults