Unit 2 | Nutrition Science

What are the 5 steps of the scientific method, in order?

Observation/Question, Hypothesis, Experiment, Analysis, Conclusion

What is a hypothesis?

A testable, educated guess that explains an observation

What is peer review?

The process by which research papers are evaluated by other researchers before publication in scientific journals

Why is sharing scientific findings important?

So others can build on discoveries and to develop collaborations

What are the two main ways researchers report findings?

Presenting at scientific conferences and submitting manuscripts to peer-reviewed journals

List the 4 main categories in the nutrition evidence pyramid from lowest to highest strength

Non-human studies, observational studies, intervention studies, meta-analyses/systematic reviews

What are non-human studies useful for?

Understanding mechanisms (how and why), under tightly controlled, fast, low-cost conditions

What is a major limitation of non-human studies?

Results don't necessarily apply to humans or real-life nutrition decisions

What do observational studies measure?

Correlations between variables, without any treatment or intervention

What is a confounding factor?

A factor other than the variable being studied that could affect the outcome

True or False: Correlation implies causation

False

What is a cohort study?

A study that follows a group of people over time, measuring factors like diet and health outcomes

What is a prospective cohort study?

A study that enrolls a cohort and follows them into the future

What is a retrospective cohort study?

A study that looks back at what already happened to people in the past

Why are retrospective cohort studies weaker than prospective ones?

People may not recall the past accurately (recall bias)

What is a case-control study?

A study comparing a group of cases and controls to find differences that explain different health outcomes

What is a cross-sectional study?

A study that collects information about a population at one single point in time

What is an intervention (experimental) study?

A study where the researcher imposes a treatment or change and measures its effects

Can intervention studies establish cause and effect?

Yes, if well-designed, such as an RCT

What is a Randomized Controlled Trial (RCT)?

The gold standard intervention study design that randomly assigns participants to control and treatment groups

Why does randomization matter in an RCT?

It makes the groups alike in every way except the experimental condition

What is the placebo effect?

When believing you are receiving treatment (and expecting benefit) changes the outcome, independent of the actual treatment

What is a double-blind study?

A study where both research staff and participants do not know which group the participant is in

Why are placebo-controlled, double-blind trials the strongest intervention design?

They control for the placebo effect and bias from staff or participant expectations

What is a systematic review?

A review that examines and summarizes studies already published on a topic

What is a meta-analysis?

A study that statistically combines data from multiple studies and analyzes them as a group

Why are systematic reviews and meta-analyses considered strong evidence?

They summarize what is known from multiple studies rather than relying on one study

Why is no single nutrition study considered conclusive on its own?

Science builds on a foundation of multiple studies; individual studies vary in value and strength

Name 3 major challenges in nutrition research

Reliance on observational data, confounding lifestyle/social factors, and difficulty accurately measuring diet

Why are RCTs rare in nutrition research?

They are often small, short-term, and diet is exceedingly complex to control

How can industry funding bias nutrition research?

Studies funded by the food industry may be biased toward results that benefit business rather than human health

What questions should you ask when reading about a nutrition study in the news?

Was it peer-reviewed? What study type? Are results meaningful in real life? Consistent with prior research? Does it make sense?

What does CRAAP stand for in evaluating sources?

Currency, Relevance, Authority, Accuracy, Purpose, Process

What does the "Currency" in CRAAP assess?

When the page or article was created or last updated

What does the "Authority" in CRAAP assess?

Who the author is and what credentials they have

What does the SIFT method stand for?

Stop, Investigate the source, Find trusted coverage, Trace claims back to original context

What does "Investigate the source" mean in SIFT?

Research the creator's expertise and agenda, reading laterally off the original page

What does "Trace" mean in SIFT?

Follow claims, quotes, and media back to their original context or source

Name 3 red flags of junk science

Promises a quick fix, oversimplified conclusions from complex studies, and recommendations aimed at selling a product

What domain extensions are generally the most authoritative for nutrition info?

.gov and .edu

Why should you be cautious with .org and .com websites?

They are mixed sources — some are credible and some are not

Is "nutritionist" a regulated professional title?

No, it is an unregulated title anyone can use

What credential is regulated and evidence-based in dietetics?

Registered Dietitian (RD) or Registered Dietitian Nutritionist (RDN)

What degree is required to become an RD/RDN starting in 2024?

A master's degree in dietetics

How many supervised practice hours does a dietetic internship require?

1,200 hours

What must an RD/RDN candidate pass to become registered?

A national exam

How does an RD/RDN maintain their registration?

Through continuing education

Besides RD/RDN, what other professionals are considered trustworthy nutrition experts?

Those with an MS or PhD in nutrition, or an MD with nutrition training and expertise

Name 3 government/professional organizations considered trustworthy nutrition sources

USDA, CDC, and the Academy of Nutrition and Dietetics

Name 3 career settings for Registered Dietitians

Hospitals/clinics, government, and education