Evidence Grade E
Practitioner experience without formal trials
What Grade E Means
Grade E represents clinical consensus — findings based on accumulated practitioner experience rather than formal research trials. These are patterns that experienced clinicians consistently observe in practice, even when published studies don't directly address them.
- Experienced practitioners agree on this pattern
- Clinical observation is consistent across multiple practitioners
- Formal research hasn't specifically tested the claim
- The finding may eventually be confirmed or refined by research
Grade E is not "bad evidence" — it's a different type of evidence. Medical practice has always relied on clinical wisdom alongside research data.
Criteria for Grade E Classification
A finding receives Grade E status when:
1. Practitioner Agreement
Multiple experienced clinicians in the relevant field report the same observation or use the same approach.
2. Consistent Clinical Patterns
The finding reflects patterns seen repeatedly in patient care, not isolated anecdotes.
3. Absence of Formal Research
While clinical experience supports the claim, controlled studies haven't directly tested it.
4. No Contradictory Research
Formal studies haven't demonstrated the opposite of what practitioners observe.
5. Biological Plausibility
The finding makes sense within established physiological frameworks.
Why Clinical Consensus Matters
Research Gaps Are Real
Many practical clinical questions have never been studied. Research funding follows certain patterns, leaving gaps in formal evidence.
Practitioners See What Trials Miss
Randomized trials select specific populations and measure specific outcomes. Practitioners see the full diversity of patient responses.
Speed vs. Rigor
Clinical observation can identify patterns years before formal research confirms them. Waiting for RCTs on every question would paralyze clinical care.
Individual Variation
Trials report averages. Practitioners learn which patients respond to which approaches — nuance that doesn't appear in aggregate data.
The Limitations of Clinical Consensus
Grade E evidence has real limitations:
Confirmation Bias
Practitioners may remember cases that confirm their beliefs and forget contradicting ones.
Selection Effects
Certain patients seek out certain practitioners, potentially skewing observations.
Placebo and Context
Improvements may reflect therapeutic relationship, expectation, or regression to mean rather than the specific intervention.
Slow to Correct
Unlike research, clinical consensus can persist even when wrong because there's no formal testing mechanism.
Variable Expertise
Not all practitioners have equal insight. Consensus among metabolic health specialists may not match consensus among generalists.
Examples of Grade E Evidence
Optimal Fasting Insulin Targets
Fasting insulin below 5-6 μIU/mL represents optimal insulin sensitivity, not just "normal."
Source: Low-carb/metabolic practitioners (Berry, Bikman, Naiman, etc.)
Why Grade E: No RCT has compared outcomes at fasting insulin of 3 vs. 5 vs. 8. Practitioners consistently observe this pattern. Aligns with HOMA-IR research showing lower is generally better.
Status: Likely directionally correct. Exact threshold may vary individually.
Triglycerides as "Overfat" Indicator
Triglycerides above 100 mg/dL suggest the individual is above their personal fat threshold, regardless of BMI.
Source: Ted Naiman and other metabolic practitioners
Why Grade E: No formal validation of 100 mg/dL as universal threshold. Consistent observation in low-carb clinical practice. Aligns with Grade A research on TG/HDL as metabolic marker.
Status: Useful clinical heuristic. Individual variation exists.
Signs of Hidden Insulin Resistance
Skin tags, acanthosis nigricans (dark neck patches), and difficulty losing weight despite caloric restriction suggest insulin resistance even with normal glucose.
Source: Metabolic medicine practitioners
Why Grade E: Some research links these signs to IR, but sensitivity/specificity vary. Practitioners use these as clinical triggers for further testing.
Status: Useful screening heuristic. Should prompt testing, not diagnosis.
Individual Carbohydrate Tolerance Variation
Optimal carbohydrate intake varies dramatically between individuals — from near-zero to several hundred grams daily.
Source: Clinical observation across metabolic, functional, and sports nutrition practice
Why Grade E: CGM data increasingly supports individual variation. No RCTs have systematically mapped individual thresholds.
Status: Almost certainly true. Practical determination methods still emerging.
How We Use Grade E Evidence
On Metabolicum, Grade E evidence appears:
- As practitioner perspective — "Clinicians often observe..." or "In clinical practice..."
- With attribution — Naming the practitioners or communities where consensus exists
- As starting points — Suggestions for personal experimentation, not definitive answers
- With calibration — Acknowledging limits of clinical wisdom
We do NOT use Grade E evidence for:
- • Primary calculator thresholds
- • Definitive health claims
- • Statements without caveat
Grade E vs. Anecdote
Grade E is not the same as personal anecdote:
NOT Grade E:
- "My cousin tried X and it worked"
- Social media testimonials
- Single practitioner's pet theory
- Contradicted by research
- Implausible mechanism
Grade E IS:
- Multiple experienced practitioners independently observe the same pattern
- Clinical consensus among credentialed professionals
- Agreement across practitioners from different backgrounds
- Unaddressed by research
- Plausible within known physiology
The Value of Named Practitioners
When Grade E evidence comes from specific practitioners, we name them:
This allows you to evaluate the source's expertise and potential biases, explore their reasoning in their own content, and track whether their observations are later confirmed by research.
When Grade E Is Your Best Option
Grade E evidence becomes particularly valuable when:
Research Doesn't Exist
Your specific question hasn't been studied. Clinical wisdom is the only guidance available.
You Don't Match Research Populations
Studies were done on different demographics. Practitioners who've worked with people like you offer relevant experience.
Fine-Tuning
Research establishes general principles. Grade E helps apply them to your specific situation.
Low-Risk Decisions
When the intervention being considered is safe, Grade E can guide reasonable experimentation.
The Path from E to Higher Grades
To Grade D:
Mechanistic research validates the underlying biology. The hypothesis becomes formally testable.
To Grade C:
Observational studies document the pattern.
To Grade B/A:
Controlled trials test and confirm the clinical observation.
Some Grade E findings never get formally studied but remain useful clinical wisdom.
Being Honest About Source
We distinguish between:
This distinction matters for assessing confidence levels, understanding how knowledge might change, and deciding how much weight to give a claim.
Grade E Citations on Metabolicum (0)
No Grade E citations currently in database. Clinical consensus is referenced inline in educational content.
See also
Evidence grades are informational and do not replace medical advice.