What is evidence-based practice in nutrition?

Using best available research evidence to guide nutrition decisions

What is the goal of evidence-based practice?

Develop reliable nutrition recommendations based on research

Why is evidence-based practice important?

Ensures safe, effective, and scientifically supported care

What is the hierarchy of evidence?

Ranking of study types based on strength and reliability

What is the highest level of evidence?

Systematic review and meta-analysis

What is the gold standard individual study?

Randomized controlled trial (RCT)

List study types from lowest to highest evidence

Case report → cross-sectional → case-control → cohort → non-randomized trial → RCT → systematic review/meta-analysis

What are observational studies?

Studies observing associations without intervention

Examples of observational studies

Case report, cross-sectional, case-control, cohort

Do observational studies show cause and effect?

No (only associations)

What is a case report?

Description of one or a few cases without control group

What is a limitation of case reports?

Low statistical validity

What are case-control studies?

Compare people with disease to those without (retrospective)

What is a limitation of case-control studies?

Recall bias and no causation

What are cross-sectional studies?

Data collected at one time point

What is a limitation?

No cause-effect relationship

What are cohort studies?

Follow exposed vs non-exposed groups over time

What is strength of cohort studies?

Show temporal relationships

What is limitation?

Confounding variables; no causation

What are intervention studies?

Studies that introduce a treatment or exposure

What is an RCT?

Randomized study comparing intervention vs control

Why are RCTs strong?

Reduce bias and show cause-effect

What is a non-randomized trial?

Intervention study without randomization

What is limitation?

Less robust than RCT

What is a systematic review?

Summary of multiple studies answering a focused question

What is a meta-analysis?

Statistical combination of results from multiple studies

Why are meta-analyses powerful?

Increase sample size and statistical power

What are in vitro studies?

Cell/tissue studies in lab

What is limitation of in vitro studies?

Low generalizability

What are animal studies?

Studies in living organisms (non-human)

What are advantages?

Controlled, mechanism testing

What is limitation?

Less generalizable to humans

What are behavioral studies?

Test interventions in real-world settings

What is robustness (R)?

Strength and control of study design

What is generalizability (G)?

Ability to apply results to real population

What is the main trade-off in research?

High control (R) vs real-world applicability (G)

What factors should be considered when evaluating evidence?

Study type, population, methods, results, bias, limitations

What population factors matter in studies?

Sample size, inclusion/exclusion criteria

What methodological factors matter?

Randomization, blinding, control groups

What is bias?

Systematic error affecting study validity

What is selection bias?

Improper randomization or group selection

What is performance bias?

Differences in treatment exposure

What is detection bias?

Differences in outcome assessment

What is attrition bias?

Dropouts affecting results

What is reporting bias?

Selective reporting of outcomes

What is financial bias?

Funding influencing results

What tool is used to assess bias?

Cochrane Collaboration tool

What is PEN?

Practice-based Evidence in Nutrition (resource by Dietitians of Canada)

What does PEN provide?

Evidence-based recommendations for dietitians

What are PEN evidence grades?

A, B, C, D

What does grade A mean?

Good evidence

What does grade B mean?

Fair evidence

What does grade C mean?

Limited evidence

What does grade D mean?

Very limited or conflicting evidence

What is an example of applying evidence?

Egg intake and CVD risk in diabetes

What did RCT evidence show for egg intake?

No adverse effect on major CVD risk factors

What was limitation of egg studies?

Few studies and small sample sizes

Why must results be interpreted carefully?

Limited generalizability and study design differences

What is an important step in evidence-based practice?

Critically evaluate research before applying

What is a major issue in nutrition research?

Conflicting recommendations

Why do conflicting recommendations occur?

Different study types, bias, and interpretation

What is the main takeaway about evidence-based recommendations?

They take time and evolve with new research

What is a key controversy example?

Seven Countries Study

What was criticism of the Seven Countries Study?

Data selection bias (“cherry-picking”)

What is a key lesson from research controversies?

Always critically evaluate evidence and bias

Why has trust in nutrition research been affected?

Conflicting findings and bias concerns

What is a modern approach to evidence?

More strict evaluation and bias control

What is a limitation of being too strict?

May exclude useful studies