1. Scientific Method Nutrition Science Textbook Observation Hypothesis
Experiment
… and that’s it…?
Scientific Method

2. Scientific Method

3. Scientific Method

4. Step 1: Observation Accurate – what does it mean?
Calorimeter lab – not very specific…
Cashews contain a lot of energy, or
Beans contain less energy than nuts, or
Almonds contains more energy than cashews, or
Foods yield more energy when oxidized in a bomb calorimeter, etc.
Hypothesis explains the observation
Step 1: Observation

5. Step 2: Hypothesis Plant growth may be affected by the color of light.
Ultraviolet light may cause skin cancer.
Step 2: Hypothesis

6. Causative & Correlative
If leaf color change is related to temperature, then exposing plants to low temperatures will result in changes in leaf color.
If skin cancer is related to ultraviolet light, then people with a high exposure to uv light will have a higher frequency of skin cancer.
Step 2: Hypothesis

7. Complex relationships
Correlative
Can be a + or - correlation
Complex relationships
Interactions of many variables
Step 2: Hypothesis

8. Step 3: Experiment Epidemiologic studies Intervention studies

9. Epidemiology Epi – upon, among Demos – people, district
Logos – study, discourse
The study of what is upon the people
This term is now applied to study of animals and plants as well.
Before: epidemic diseases
Now: also health-related issues
Step 3: Experiment

10. Epidemiology
The science of study of patterns and effects of health conditions in defined populations.
Public health studies  policy decision
Clinical research  evidence-based medicine
Basic research  develop methodology
Step 3: Experiment

11. Epidemiologists rely on…
Scientific disciplines like Biology to better understand disease processes,
Statistics to make efficient use of the data and draw appropriate conclusions,
Social sciences to better understand proximate and distal causes, and
Engineering for exposure measurement.
Step 3: Experiment

12. Many epidemiologists are physicians, or hold graduate degrees such as
Master of Public Health (MPH)
Master of Science of Epidemiology (MSc.)
Doctorates include the Doctor of Public Health (DrPH)
Doctor of Pharmacy (PharmD)
Doctor of Philosophy (PhD)
Doctor of Science (ScD)
Doctor of Podiatric Medicine (DPM)
Doctor of Veterinary Medicine (DVM)
Doctor of Nursing Practice (DNP)
Doctor of Physical Therapy (DPT)
Doctor of Medicine (MD)
Doctor of Osteopathy (DO).
Step 3: Experiment

13. Intervention Studies Control and experiment groups
Phenomena that could affect the results
Placebo effect
Hawthorne effect
Researcher bias
Preventive measure
single- or double-blind study
Placebo-controlled
Random assignment
Step 3: Experiment

14. The rest of the Scientific Method
Step 4: data analysis
Step 5: conclusion
More: revise hypothesis, reproduce experiment, peer review, more experiments, etc.
More: Analysis & Conclusion

15. Nutrition Claims How do you know which ones are believable?
Source of info – primary source ex. peer-reviewed journals
Researchers – professors or medical doc
Funding Agencies – unbiased, have nothing to gain from the study
Scientific method
Public health organizations

16. Source of information
Researcher credibility
Who paid for the research?
Evaluate experimental design
Do public health organization agree?

17. Societal Health
"A society is healthy when there is equal opportunity for all and access by all to the goods and services essential to full functioning as a citizen" (Russell 1973).
existence of the rule of law
the level of social capital
equality in the distribution of wealth
public accessibility of the decision-making process
Gale Encyclopedia of Public Health, 2002

18. Societal Health How one interacts within social institutions
How one gets along with others
How people react to this individual
Social health has also become relevant with the increasing evidence that those who are well integrated into their communities tend to live longer and recover faster from disease. Conversely, social isolation has been shown to be a risk factor for illness.
Gale Encyclopedia of Public Health, 2002

19. Who Monitors Societal Health
World Health Organization (WHO)
Centers for Disease Control and Prevention (CDC)

20. Indicators of Societal Health
Mortality rate: no. of deaths in a given population at a given period of time
Infant mortality rate: same as above but for babies
Morbidity rate = incidence + prevalence
no. of sick ppl in a … same as above…
Life expectancy: “maximum lifespan”
Infectious and noninfectious diseases