Chapter 26 — Exercises

Three tiers. 🔄 retrieval; 🪞 reflection.

Tier 1 — Recall and Comprehension

R1. Give §26.1's four tiers with examples. ⚠️ What determines which tier something falls into?

R2. ⚠️ State §26.1b's unifying frame. Which five conditions does it connect, and by what mechanism?

R3. Give §26.1b's two qualifications. ⚠️ Why does waist measurement add what BMI misses?

R4. ⚠️ Give DiRECT's remission rates at 12 and 24 months, and the dose-response gradient by weight lost.

R5. Name the four clinical qualifications to the remission finding. ⚠️ Which is the safety one?

R6. ⚠️ State the four lines of evidence establishing LDL-C causality. Why does convergence matter more than any one of them?

R7. Give the LDL-C reduction magnitudes for each dietary intervention, and for statins. ⚠️ What does the chapter conclude about "diet instead of a statin"?

R8. ⚠️ What is ApoB, and when does it disagree with LDL-C? Which population shows discordance most?

R9. Why is HDL-C described as a marker rather than a target? ⚠️ What evidence settled that?

R10. ⚠️ What is Lp(a), why doesn't diet move it, and what should you do about a raised result?

R11. Describe the DASH trials. ⚠️ What did DASH-Sodium add?

R12. ⚠️ Describe the salt-substitute trial and what makes it unusual. State the contraindication.

R13. ⚠️ Where does the chapter land on sodium, and give the three reasons it discounts the J-curve cohorts.

R14. Give the weight-loss dose-response for fatty liver disease. ⚠️ What is MASLD?

R15. ⚠️ Name six established diet-related cancer risk factors and five claims that do damage.

R16. ⚠️ How do nutritional goals change during cancer treatment? Give five.

R17. ⚠️ List everything that inverts in CKD. What happens on dialysis?

R18. ⚠️ Why does the phosphate-additive point matter more than "cut dairy"?

R19. Give §26.13b's timelines. ⚠️ Why must you not recheck HbA1c at four weeks?

R20. ⚠️ What was PREDIMED, what did it find, and what happened to it in 2018?

Tier 2 — Application

A1. 🔄 Sort the panel. For each result, give the tier from §26.1 and the realistic magnitude of dietary change:

a) HbA1c 7.6% · b) Lp(a) 140 nmol/L · c) Triglycerides 3.8 mmol/L · d) LDL-C 4.9 mmol/L in familial hypercholesterolaemia · e) ALT 78 U/L · f) BP 152/94 · g) Urate 0.51 mmol/L

A2. ⚠️ The remission conversation. A 54-year-old was diagnosed with type 2 diabetes three years ago. BMI 34, A1c 7.9%, on metformin only.

a) Is remission realistic? What determines it? b) ⚠️ What weight loss would you quote, and with what probability? c) What has to happen before they start? d) ⚠️ How does the answer change if they are also on gliclazide?

A3. The statin conversation. Someone at high cardiovascular risk wants to "try diet first."

a) ⚠️ What is the honest magnitude comparison? b) Write what you'd say, in under 60 words, without being dismissive. c) ⚠️ What would make you more sympathetic to their position?

A4. One process, five diseases. A patient has fatty liver, prediabetes, hypertension and raised triglycerides.

a) ⚠️ Explain to them why these arrived together. b) What single intervention addresses all four, and what dose? c) ⚠️ What order will the numbers move in? (§26.13b)

A5. ⚠️ The inversions. For each, state what general advice would be and what actually applies:

a) An 82-year-old with CKD stage 4 and a BMI of 22 b) Someone mid-chemotherapy who has read about "anti-cancer" diets c) Someone on dialysis asking about protein d) Someone with CKD stage 3 who has just bought a potassium salt substitute e) An older adult with type 2 diabetes losing weight unintentionally

A6. Read the timeline. Someone starts a dietary change and rechecks bloods at four weeks.

a) ⚠️ Which results will have moved, and which won't? b) What should have been measured, and when? c) ⚠️ What is the likely consequence of the four-week HbA1c, behaviourally?

Tier 3 — Analysis and Synthesis

S1. What a settled question looks like. §26.5 contrasts LDL-C's evidence with Part IV.

a) ⚠️ List every feature that makes it settled. b) Apply the same checklist to three Part IV claims. How many features does each have? c) ⚠️ Is there any nutrition claim that could reach this standard? What would it take?

S2. ⚠️ The biomarker–event gap. The chapter concedes we know far more about biomarkers than events.

a) Why? Give three structural reasons. b) ⚠️ What does that imply about acting on biomarker evidence? When is it justified? c) §26.7's salt-substitute trial is the exception. ⚠️ Why was it possible when others aren't?

S3. The sodium question. §26.8 discounts the J-curve cohorts for three reasons.

a) ⚠️ Steelman the J-curve position. What would its advocates say to each of the three? b) Design the study that would settle it. Why hasn't it been done? c) ⚠️ Chapter 14 deliberately left this unresolved and Chapter 26 resolves it partially. Was that the right structural choice for a textbook?

S4. ⚠️ The restriction failure mode. §26.11b generalizes across cancer and CKD.

a) ⚠️ Find two more conditions where the same pattern operates. b) Why are seriously ill people especially vulnerable to it? Give three reasons. c) ⚠️ Design the question a clinician should ask instead of "what should I cut out?"

S5. PREDIMED, honestly. The trial was retracted and republished.

a) ⚠️ How much should that change your confidence, and why? b) Compare it to the Séralini retraction (Chapter 20 §20.9). ⚠️ Why do these two retractions mean different things? c) Should a textbook cite a republished trial? ⚠️ How should it be flagged?

S6. 🔄 ⚠️ The responsiveness column. §26.1 argues nobody adds it to a results letter.

a) Design the results letter you'd want. What does it contain? b) ⚠️ What are the risks of giving patients a "responds to food?" column? c) Would it change behaviour? ⚠️ How would you test that, and what would you measure?

🪞 Reflection

M1. ⚠️ Do you know your own numbers? Which tier is your worst one in?

M2. ⚠️ Have you ever been told to "watch your diet" without being told what it would move? Did you know which of your results were tier 4?

M3. §26.5 says diet and statins are additive, not alternative. ⚠️ Does that sit comfortably with you? If not, examine why — is it evidential or is it about virtue? (Chapter 24 §24.11 asked the same question about a different drug.)

M4. ⚠️ §26.10 says the person most likely to be harmed by nutrition advice is someone in cancer treatment given a restrictive diet by someone who meant well. Have you ever recommended a diet to someone who was seriously ill?

M5. 🔄 ⚠️ §26.13b says people quit on measurements that were never going to move. Have you? What were you measuring, and how soon?