Lecture: Intro to Nutrition, Nutrients, and Malnutrition
What is nutrition?
Why study nutrition?
 Diet-related causes of death

Obesity rates
The Changing American Diet
 Changes between 1970-2005
Introduction to the Nutrients
What is a nutrient?
6 classes of nutrients:

Macronutrients vs. micronutrients

Definition of an essential nutrient
o


How can you tell if a nutrient is “essential”?
Definition of organic nutrient:
o
Examples of organic nutrients
o
Examples of inorganic nutrients
What’s an “organic food”?
Nutrition 12
The Energy-Yielding Nutrients

What is meant by “energy”?

Form of chemical energy used in the body:

The calorie: a unit of heat energy
Calories provided by dietary substances:
 Carbohydrate
 Protein
 Lipids
 Alcohol
Problem: Calculate the energy content of 1 serving of See’s milk chocolates:
 Total fat: 12 g
 Total carbohydrate: 27 g
 Protein: 3 g
 How many Calories in a milk chocolate?
 About what percent of its calories comes from fat?
Recommendation for % of Calories from Energy-Yielding Nutrients
 Carbohydrate
 Protein
 Lipids
Nutrient Density

Definition of nutrient density

Examples of nutrient-dense food choices
General Functions of Nutrients
1.
2.
3.
Body composition: water, protein, fat, minerals
Examples of non-nutrients
 Phytochemicals

Probiotics
Functional foods defined:
Introduction to Malnutrition
Undernutrition vs. overnutrition
Causes of nutrient deficiencies
 Primary

Secondary
Assessment of nutrition status
 A:

B:

C:

D:
Anthropometric data:
Laboratory tests (Biochemical data):
Physical examination (Clinical data):
Dietary assessment:
Examples:
24-hr recall
Food frequency
Food record (diet analysis)
Stages in the Development of a Nutrient Deficiency:
see figure in textbook…
Introduction to Nutrition Research
Finding reliable nutrition information…

Which resource provides the most accurate information?
Reputable Nutrition Credentials

Examples include:

Degree mills – do they provide expertise?
Scientific Method in Nutrition Research
Define the “scientific method.”
Steps of the scientific method:
1.
2.
3.
4.
Continuum of Reliability of Information
Nutrition Studies
I. Epidemiological studies
Examples of Epidemiological Studies
Cross-sectional study:
Retrospective (case-control study):
Prospective (cohort study):
Evaluating relationships between variables
 Positive correlation
 Negative correlation
 No correlation
More correlation terminology
Epidemiological Studies: how results are expressed
Summary: Elements of Epidemiological Studies
o
Find relationships
o
Observational
o
No “cause and effect” shown
Question: Which type of study is more accurate… prospective or retrospective?
Example of ongoing observational study
 NHANES – National Health and Nutrition Examination Surveys
Experimental studies
 Prospective
 Intervention
 Random assignment
 Treatment vs. placebo
 Determine “cause and effect” relationships
Elements of high-quality experimental studies
 Randomization
 Single blinded vs. double blinded
 Placebo controlled
 Peer review
 Replication
The Placebo Effect
Interpreting the results…
 Statistical significance
 Was treatment success due to the treatment, or luck (“chance”)?
 Clinical relevance
Animal and Cell Culture Studies
 Animal studies
 Cell or tissue culture
Making Sound Decisions about Nutrition Studies

How do you know if nutritional claims are sound?
Publication of Research Studies
•
Nutrition, medical, dietetics journals
Peer Review
See Table 1-3 (p. 13) and Figure 1-4 (p. 14)