HNF 150 - Nutrition Basics and Science (week 1 & 2)

Health

a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity

What can be qualified as “Health”?

diet, exercise, emotional, social, spiritual, intellectual, environmental, occupational

Nutrition

the study of how food nourishes the body (human eating behavior, government influence on eating, ethics of food production)

Science

the process by which scientists, collectively and over time, endeavor to construct an accurate representation of the world

true or false: nutrition is a science

true

True or false: nutrition is NOT a multi-disciplinary science

False

Nutrition is the biochemical interaction between…

food and beverages, nutrients, genetics and their action, interaction and balance in relation to health and disease

What are some genetic diseases (nutrition has no impact on)?

down syndrome, hemophilia, sickle-cell anemia

What are some nutrition-related diseases?

iron-deficiency, anemia, vitamin & mineral deficiencies, toxicities, poor resistance to disease

What diseases do nutrition have some effect on?

diabetes, hypertension, heart disease

what diseases do nutrition have little effect on?

adult bone loss, cancer, infectious diseases

How many adults in the US have a chronic disease?

60%

sustainability

the ability to meet the needs of the present without compromising the ability of future generations to meet their own needs

True or false: the health of soil is unimportant to the health of plants and people

False

Vitamin C

• protects cells against damage

• important for healthy gums & skin

• helps absorb iron

• prevents SCURVY

What colors of plants contain vitamin C?

red, orange, green

What fruit or vegetable provides the highest amount of vitamin C?

red pepper, orange, green pepper

Nutrients

components of food that are indispensable to the body’s functioning

What four things do nutrients provide?

• Energy

• Serve as building material

• Maintain or repair body parts

• Support growth

Nutrients must be obtained from an _______ source

external - because we cannot make enough of it ourselves

An “essential” nutrient must have an

identified biological function

What are the main types of nutrients?

• water

• carbohydrates

• fats

• proteins

• vitamins

• minerals

Calories

energy

What is 1 calorie equivalent to?

the amount of heat needed to raise the temperature of 1 liter of water 1 degree Celsius

Which nutrients have calories?

carbohydrates, proteins, & fats

How much energy do carbohydrates have?

4 kcal/g

How much energy do lipids have?

9 kcal/g

How much energy do protein have?

4 kcal/g

How much energy does alcohol have?

7 kcal/g

Nutrient Density

foods rich in nutrients relative to their energy content (lower calories but higher nutrients)

What type of foods are typically nutrient dense?

whole foods

Nutritious (Optimal) Diet

• maximizes health & longevity

• prevents nutrient deficiencies

• decreases risks for chronic diseases

What is a nutritious diet composed of?

a variety of nutrient dense, whole foods that are available, safe and palatable

True or false: humans have nutritional wisdom

true

what is evidence that humans have nutritional wisdom?

• recipes

• remedies

• feeling better when we do something

true or false: humans are NOT born with innate nutrition knowledge

false

True or false: nutrition is a young science

True - first vitamin identified in 1897

What are the steps of the scientific method?

• observation & question

• hypothesis & prediction

• experiment

• results & interpretations

• IF hypothesis is supported: theory

• IF hypothesis is not supported: start over

Observation & Question

identify a problem to be solved or ask a specific question to be answered

Hypothesis & Prediction

formulate a tentative solution to the problem or answer to the question and make a _____ that can be tested

experiment

design a study and conduct the research to collect relevant data

results & interpretations

summarize, analyze, and interpret the data; draw conclusions

theory

develop a ________ that integrates conclusions with those from numerous other studies

Why are replication & peer review important?

• independent experimenters do the study multiple times

  • one study is NEVER enough

  • scientists write up their methods and findings and have other scientists review the material

What are the two types of peer-reviewed journals?

1. research journals

2. review journals

Research Journal

reports the details of the methods, results and conclusions of recently completed experiments

Review Journals

examines all available evidence on major topics

Why do we measure diet and nutrition?

• follow individual dietary patterns

• assess exposure to food, nutrients, & non-nutrients

• identify population groups with no access to adequate nutrition

What are the 4 categories to measure nutrition?

• anthropometry

• clinical examination

• diet questionnaires

• biomarkers

anthropometry

body measures, height, weight

clinical examination

physical signs associated to severe vitamin or mineral deficiencies

diet questionnaires

measure various aspects of our diet & nutrition knowledge

24-hour recall

• diet questionnaire

• records all food & fluid intake for previous 24 hours

• average of 3 random 24-hour recalls

• Issues: recall problems with food portions

• digital cameras help with memory

what is an example of 24-hour recall?

national health and nutrition examination surveys (NHANES)

food frequency questionnaire (FFQ)

• measures usual amounts of food commonly eaten over a time period

• strengths: some food frequencies ask portions & it is nutrient specific or general diet

• weaknesses: hard for participants to remember portions cause of long time period

Biomarkers

measure nutrients or metabolites in biofluids (blood, urine) or tissues (hair, nails)

examples of biomarkers

protein intake, sugar intake, urinary nitrogen

Garlic

• member of allium family

• edible portion is the bulb

• each clove can grow into a new plant

• originated in Asia

• contains sulfur compounds - smell when crushed

• antimicrobial & antifungal & prevents blood clots

• enhances absorption of iron & zinc

• rich in calcium, phosphorous, iron, thiamin, & vitamin C

What are the types of observational studies?

1. case study

2. qualitative study

Case study

• studies individuals with no comparison group

  • narrative studies of individuals

• offers starting point for further research

  • does NOT establish cause & effect

true or false: case study observation may be by chance

true

qualitative study

• narrative studies of many individuals

• findings are not quantifiable

what are types of epidemiological studies?

• cross-sectional

• migration

• case control

• cohort

epidemiological studies

studies of populations

cross sectional studies

measures disease/condition at one time point between two or more groups and this conclusion can lead to an association (NOT CAUSATION).

migration study

observes how a disease/condition changes after moving

case control (retrospective) study

identifying cases (those with disease) and comparing to controls (those without disease)

Cohort (prospective) study

follows healthy population to see how many people develop the disease/condition

what are the types of experimental/intervention studies?

laboratory studies & clinical trials

What are types of laboratory studies?

animal, human, cell (in vitro)

what are the types of clinical trials?

randomized & double blind

experimental (intervention) studies

researchers actively intervene in one group of the population (experimental group) and compare to a group that does not receive the intervention (control group).

human laboratory studies

experimental studies performed with humans under tightly controlled situations

animal laboratory studies

studies performed with animals under tightly controlled situations

in vitro studies

studies of cells that are outside of the body

What is a placebo?

the intervention group gets a false treatment to create a control group

What is double blind?

neither the subjects in the study, nor the researchers know to which group the subjects belong until the end of the experiment

How do we weight the evidence from a study?

1. look at ALL studies (consistent, specific, strong correlations)

2. many studies were conducted

3. quality of evidence (meta-analyses & systematic review is the best)

4. look out for conflict of interest (certain companies funding certain research)

5. ask if the findings make sense at the cellular, biological, psychological, or social level?

true or false: garlic intake lowers the risk of cancer by about 69%

true

What are the health properties of garlic?

• antibacterial

• block the formation and activation of cancer-causing substances

• enhance DNA repair

• reduce cell proliferation

• induce cell death

Dr. Clara Davis

• conducted a classic 1920’s study of infant feeding

• learning to eat = repeated exposure + learned safety + associative condition

  • infants figured out good food based on how they felt after eating it

Dr. Leanne Birch

• food preference is developed by exposure, social learning, & genetics

• children are able to adjust meal sizes to meet their needs

true or false: animals choose plants on taste AND what they have to offer

True

Palability

involves feedback from cells & organ systems including the microbiome

true or false: animals do not avoid nutrient deficient diets

False - they explore new foods to prevent deficiency

digestion

breaking down & absorption of food - where energy comes from

energy balance is equivalent to

energy intake - energy expenditure

BMI formula

weight/height * 705

What is causing the rise in obesity & diabetes?

affordability, convenience, availability, technology, innate knowledge

correlation

a connection between two or more things

causation

the action of causing something

does correlation equal causation?

no

is fitness or fatness more important for health?

fitness

dieting

restricting oneself to small amounts of special kinds of food in order to lose weight

What are the harms of dieting?

• weight cycling

• increased risk for weak bones

• increased anxiety

• eating disorders

• weight gain

what do epidemiologic studies (typically) not control for?

• fitness

• nutrient intake

• socioeconomic status

• body image

• weight cycling

cardiorespiratory fitness

submaximal or maximal exercise tests of work performance

Health at every size HAES

supports people in adopting health habits for the sake of health and well-being RATHER than weight control

what does HAES encourage?

• following hunger cues

• finding joy in being active

• accepting and respecting all body sizes and shapes

what all does health include?

• good nutrition

• physical activity

• supportive relationships

• purpose of life

• meaning in work

• healthy emotions