Prelim 1 NS 1150

Nutrition is

the sum total of processes involved in the intake and utilization of food
substances by living organisms

Metabolism

all chemical processes that occur within a living
organism (a cell) to maintain life

nutrient

substance found in foods that performs one or more physiological or biochemical
functions in the body

Major functions of nutrients

energy, structure, regulation

Which nutrients provide energy?

Mostly carbohydrates (CHO) and fat, but protein in extreme circumstances

Which nutrients provide structure?

protein

Which nutrients provide regulation?

All

Organic nutrient

has carbon atoms; carbohydrates, lipids/fats, vitamins, protein

Inorganic nutrient

doesn’t contain carbon; water, minerals

Essential nutrient

must be obtained from the diet, because the body needs it and cannot make it in the
required amounts

Nonessential Nutrient

produced/found in the body and used by the body to promote health; not
required to be consumed in the diet; phytochemicals, zoonutrients

Conditionally Essential Nutrient

normally nonessential but becomes essential under certain circumstances like disease; eg creatine/chronic kidney disease

How are nutrients classified?

organic/inorganic; essential/nonessential or conditionally essential; energy-yielding/non-energy-yielding; macro/micronutrients

Basal (resting) metabolic rate

energy needed to perform normal body functions
(respiration, circulation, digestion)

Thermogenesis

energy cost of food processing (ingestion, digestion, absorption,
transport, and storage)

Physical activity

body movement
body movement determining activity-induced

Total Energy Expenditure =

basal metabolism + thermogenesis + physical activity

Energy from foods is measured in

kilocalories

Macronutrients

Need >1g/day; lipids/fats, carbohydrates, proteins

Micronutrients

Need <1g/day; vitamins, minerals

Energy Yielding Nutrients

nutrients that participate in biochemical processes that allow us to make ATP; lipids, carbs, proteins, alcohol (not a nutrient)

Non-Energy Yielding

Essential nutrients that do not provide energy; vitamins and minerals

number of calories in lipids/fats

9 kcal/g

number of calories in carbohydrates

4 kcal/g

number of calories in proteins

4 kcal/g

number of calories in alcohol

7 kcal/g

What does water do?

transports nutrients, gases, waste products; medium for chemical reactions; regulates body temperature

Phytochemicals

health-promoting compounds found in plants; antioxidants

Zoonutrients

health-promoting compounds found in animals; antimicrobials

Functional/fortified foods

Foods that have nutrients added into them that they normally would not have

Enriched foods

Adding nutrients back into foods that were lost during processing

Dietary Reference Intakes (DRI)

Estimates how much of a nutrient is needed to optimize health, prevent disease, and avoid nutrient overconsumption

Estimated Average Requirement (EAR)

Nutrient intake value estimated to meet the requirement for 50% of healthy individuals

Recommended Daily Allowance (RDA)

Nutrient intake value estimated to meet requirements for all (97-98%) of healthy individuals

Adequate Intake (AI)

used when scientific evidence is not enough for an RDA

Upper Level (UL)

Highest level of daily nutrient intake that poses no risk of adverse health effects to most individuals

Estimated Energy Requirements (EER)

Estimated calorie needs of person based on body composition; how many calories should come from each nutrient

Dietary Patterns

long term habits of food consumption, proportions, variety, combination of food, drinks, and nutrients, and their frequency

Dietary Guidelines

Provide science-based advice on what to consume to promote health

James Lind

First randomized controlled trial, but poor documentation and influence did not have proper action taken to address scurvy

Sir Gilbert Blane

Reproduced James Lind’s study, this time with real impact

What impacts come from nutrition in a population?

Impacts development of society and economy

Types of bio-medical research

basic, pre-clinical, clinical

Basic research

seeks knowledge into fundamental properties and behavior of life molecules

Pre-clinical research

Uses animal models to test effect of an intervention (drug or strategy)

Clinical Research

Uses real human studies to dissect characteristics of disease or trial an intervention

Observational studies

No treatment assigned to participants, case control (retrospective), cohort (prospective)

Experimental studies

Treatments assigned to patients

Food and nutrition board

establishes principles and guidelines for good nutrition

Dietary Guidelines for Americans (DGA)

Recommendations on what to eat and drink to meet nutrient needs, promote health, and prevent disease, updated every 5 years

Dietary Nutritional Assessment

Record of what a person eats, retrospective or prospective, in the form of 24hr dietary recall, food frequency questionnaire, or dietary records

Clinical Nutritional Assessment

Involves learning the history of the patient’s general health and symptoms and a physical examination

Anthropometric Nutritional Assessment

Assessment of the human body’s physical dimensions and composition: height, weight, BMI, waist circumference, DEXA

How is BMI used?

to estimate body fat, risk factors, classify individuals

What are the limitations of BMI?

Muscle to adipose tissue ratio, types and distribution of adipose tissue, bone density, age, ethnicity

What is waist circumference used for?

to indicate visceral fat content (deep abdominal fat around major abdominal organs), not diagnostic

Dual-Energy X-ray absorptiometry DEXA

Used to assess bone density, lean mass, fat mass

What is BOD POD used for?

Faster but less accurate alternative to DEXA, measures body weight, volume, density, and estimates fat %

Biochemistry Assessments

quantification of specific nutrients or nutrient-derived metabolites/proteins in blood, urine, or sometimes poo (may measure macro or micros)

Acute disease

appears suddenly and lasts for a short period of time

Chronic disease

persistent and long lasting disease

Congenital disorders

Conditions present at birth

Acquired diseases

conditions developed after birth, separated into communicable and non-communicable disease

Communicable disease

both contagious and non-contagious infectious diseases —> spreads through contact with certain contaminations, caused by pathogens

Non-communicable disease

Diseases that cannot be spread from person to person, usually chronic, hard to diagnose because no symptoms until its a problem

How has top causes of death in the US shifted?

from pathogenic to non-communicable chronic diseases

Salivary Amylase

breaks down starches

Lingual Lipase

breaks down triglycerides

Mastication

Mechanical breakdown of food to increase surface area and form bolus

Mucosa