an overview of nutrition

An Overview of An Overview of NutritionNutrition

Chapter 1Chapter 1

Chapter 1 ObjectivesChapter 1 Objectives

IntroductionIntroduction

• Daily food choices• Benefit health• Harm health

• Chronic disease

• Diet = what we eat• Foods and

beverages

Food ChoicesFood Choices

• Choices are highly personal• Complex interaction of genetic, social and

behavioral motives

• Personal preference = #1• Taste: sugar, salt, fat• Genetics, hormones

• Ethnic or regional heritage and tradition• Habit


• Social interactions• Availability, convenience, and economy

• Benefits of home-cooked meals

• Positive and negative associations• Emotions

• Boredom, depression, anxiety, stress


• Values• Religious beliefs, political views,

environmental concerns

• Body weight and image• Nutrition and health benefits

• Functional foods = foods that provide health benefits beyond their nutrient contributions• Examples: tomato (lycopene), orange juice

(calcium), margarine (sterols)

The NutrientsThe Nutrients

1. Water• Inorganic• No energy

2. Minerals• Simplest nutrient• Inorganic• No energy

3. Vitamins• Organic• No Energy

1. Carbohydrates• Organic• Energy

2. Proteins• Organic• Contains nitrogen• Energy

3. Lipids/Fats• Organic • Energy

Elements in the Six Classes of Elements in the Six Classes of NutrientsNutrients

Energy-Yielding NutrientsEnergy-Yielding Nutrients

• Amount of energy in food• Depends on composition

• Using nutrients for energy• Breaking of bonds• Storage of excess energy

• Metabolism• Materials for building body tissues• Regulation of bodily activities

Energy-Yielding NutrientsEnergy-Yielding Nutrients

• Provide kcalories• Carbohydrate = 4 kcal/g• Protein = 4 kcal/g• Fat = 9 kcal/g

• Alcohol• Not a nutrient• Yields energy = 7 kcal/g

• Macronutrients vs. micronutrients

The VitaminsThe Vitamins

• Thirteen organic vitamins• Water-soluble vitamins• Fat-soluble vitamins

• Facilitate energy release• Almost every bodily action requires

assistance from vitamins

• Vulnerable to destruction• Heat (vit C), light (riboflavin)

The Minerals & WaterThe Minerals & Water

• Minerals• Do not yield energy• Sixteen essential minerals • Indestructible

• Causes of mineral losses from foods

• Bound and unable to be absorbed (phytates), leach into water (sodium)

• Water• Medium for nearly all body activities

The Science of NutritionThe Science of Nutrition

• Foundation in several other sciences• Biology, biochemistry, physiology

• Tremendous growth• Sequencing of human genome

• Nutritional genomics: nutrient-gene-disease

Conducting ResearchConducting Research

• Use of scientific method• Systematic process for conducting research

• Research studies• Controls

• Randomization

• Sample size• Placebos • Double-blind experiments

NEW OBSERVATIONS & QUESTIONS

THEORYDevelop a theory that

integrates conclusions with those from

numerous other studies.

HYPOTHESIS SUPPORTED HYPOTHESIS NOT SUPPORTED

HYPOTHESIS & PREDICTIONFormulate a hypothesis—a

tentative solution to the problem or answer to the question—and

make a prediction that can be tested.

Identify a problem to be solved or ask a specific

question to be answered.

OBSERVATION & QUESTION

RESULTS & INTERPRETATIONSSummarize, analyze, and interpret the data; draw

conclusions.

EXPERIMENTDesign a study and

conduct the research to collect relevant data.

Stepped Art

Figure 1-3 p13

Conducting ResearchConducting Research

• Epidemiological studies: incidence, distribution, control of disease in pop.• Cross-sectional studies• Case-control studies• Cohort studies

• Experimental studies: cause-and-effect relationships• Laboratory-based animal studies• Laboratory-base in vitro studies• Clinical trials

Examples of Research Designs

Fig. 1-4 (pg 14)

Analyzing Research FindingsAnalyzing Research Findings

• Correlations – only show association • Positive correlation

• Not necessarily a desired outcome

• Negative correlation• No correlation

• Cautious interpretations and conclusions• Accumulation of evidence

Publishing ResearchPublishing Research

• Peer review• Research has validity

• Findings are preliminary when published• Not meaningful by themselves

• Findings need to be replicated

Parts of a Research Article

Dietary Reference IntakesDietary Reference Intakes

• Standards defined for:• Energy • Nutrients• Physical activity

• Collaborative effort of U.S. and Canada• Recommendations apply to healthy people

• May be different for specific groups


• Estimated Average Requirements (EAR)• Average amount sufficient for half of

population

• Recommended Dietary Allowances (RDA)• Recommendations to meet needs of most

healthy people• About 98% of population

EAR and RDA ComparedEAR and RDA Compared


• Adequate Intakes (AI)• Insufficient scientific evidence• AI value set instead of RDA• Expected to exceed average requirements

• Tolerable Upper Intake Levels (UL)• Point where nutrient is likely to be toxic• Helps protect against overconsumption

Inaccurate vs. Accurate View Inaccurate vs. Accurate View of Nutrient Intakes of Nutrient Intakes


• Estimated Energy Requirement (EER)• Average dietary energy intake to maintain

energy balance• Healthy body weight

• Physical activity

• No upper level


• Acceptable Macronutrient Distribution Ranges (AMDR)• Adequate energy and nutrients• Reduce risk of chronic diseases• Range

• 45-65% kcalories from carbohydrate

• 20-35% kcalories from fat

• 10-35% kcalories from protein


• Estimates apply to healthy people• Needed adjustments

• Recommendations – not minimum levels nor optimal levels

• Goals intended to be met through diet• Apply to average daily intakes• Each DRI category serves a unique purpose

Nutrition Assessment – Nutrition Assessment – Individual LevelIndividual Level

• Deficiency or excess over time leads to malnutrition• Undernutrition and overnutrition

• Symptoms of malnutrition• Diarrhea• Skin rashes• Fatigue• Others

Nutrition Assessment – Nutrition Assessment – Individual Level Individual Level

• Creating a “total picture” of the individual1. Historical information

• Health status, SES, drug use

• Diet history – intake over several days; portion sizes; computer analysis

2. Anthropometric measurements• Height and weight – track to identify trends

3. Physical examinations

4. Laboratory tests

Stages in the Development of a Stages in the Development of a Nutrient DeficiencyNutrient Deficiency

Nutrition Assessment – Nutrition Assessment – Population LevelPopulation Level

• National nutrition surveys• National nutrition monitoring program

• Coordinates two major national surveys

• Oversample high-risk groups

• National health goals• Healthy People

• National trends

Healthy People 2020 Nutrition & Weight Status Objectives

Diet and HealthDiet and Health

• Food plays vital role in supporting health• Chronic disease – epidemic levels

• Multiple factors over multiple years

• Leading causes of death

Diet and Health

• Risk factors • Persist over time• Cluster

• Prominence of risk factors• Tobacco• Diet & activity

patterns• Others

Nutrition Nutrition Information & Information &

MisinformationMisinformation

Highlight 1

Nutrition Information & Nutrition Information & MisinformationMisinformation

• Validity of information• Who is providing information?

• Qualifications

• Internet• Anyone can publish anything

• No guarantees of accuracy

• Evaluate websites• Who, When, Where, Why, and What?

• News• Often tell lopsided story

• Testimonials

• Tight deadlines

• Limited understanding

• Current and controversial


• Identifying nutrition experts• Physicians & other health-care professionals

• Training in nutrition is limited

• Registered Dietitian (RD)• Degree and clinical internship

• National exam

• Maintain up-to-date knowledge

• Dietetic Technician Registered (DTR)


• Identifying fake credentials• Accreditation• Diploma mills• Fraudulent businesses

• Red flags of nutrition quackery• Misinformation


an overview of nutrition

Documents

nutrientyields energy

research findingscorrelations

bodily action

nutrient contributionsexamples

control of disease

weight men womenelements

orange juice calcium

political views