Appendix J — Answers to Selected Exercises

⚠️ A note on what is and is not answered here.

⚠️ TIER 1 (recall) answers are in the chapters, and every quiz already has full answers with explanations. Reproducing them would be padding.

⚠️ TIER 3 (analysis) questions mostly do NOT have answers, deliberately — several ask you to criticize this book, and supplying the criticism would defeat the exercise (Ch 38 §38.4's question 4 makes the same point).

⚠️ What follows is worked answers to TIER 2 application exercises where a reader could reasonably be stuck, plus guidance on the Tier 3 questions where "what a good answer contains" is more useful than an answer.

Part I — Foundations

⚠️ Ch 2, A1 — Place these claims on the ladder

⚠️ The skill is the ten-second test, not the precise rung. Worked examples:

⚠️ "Mice fed X lived longer" → rung 2. Not a conclusion about people. ⚠️ "People eating more X had less disease" → rung 5. Association; healthy-user bias applies. ⚠️ "In a trial, X lowered cholesterol" → rung 6. ⚠️ Causation about the MARKER. Whether it lowers events is a separate question that has surprised people before. ⚠️ "A dietitian says X" → rung 1. ⚠️ Regardless of how good the dietitian is.

⚠️ If you got the rung one step out but correctly identified species / randomization / outcome, you have the skill. The number is bookkeeping.

⚠️ Ch 4, A2 — Why does the calculation over-predict weight loss?

⚠️ Three reasons, and all three are in Chapter 4 and 5:

⚠️ 1. The 3,500-kcal rule is a linear approximation of a non-linear system. ⚠️ 2. Expenditure falls as mass falls — less tissue to move and maintain. ⚠️ 3. And adaptive changes in appetite and NEAT (Ch 5, Ch 24 §24.5) oppose the deficit.

⚠️ The equation is not wrong. It is answering a physics question, and the question was behavioural — which is Chapter 4's threshold.

Part II — Macronutrients

⚠️ Ch 9, A3 — The substitution table

⚠️ The point is that "is red meat bad?" is unanswerable without a replacement.

⚠️ A study that does not specify the substitution has not answered the question, and most headlines do not.

⚠️ Ch 11, A2 — Closing a fibre gap

⚠️ From roughly 14 g to roughly 28 g. The arithmetic that works:

⚠️ One cup of cooked lentils (~15 g) closes the gap almost by itself. ⚠️ Which is why Chapter 11, Chapter 32 and Chapter 37 all land on pulses independently — largest single lever, cheapest food per nutrient in the shop.

⚠️ Second-best: swap refined grains for intact ones across the day (~5–8 g), and add a portion of beans to something you already cook.

⚠️ Worth noticing: nothing in that answer is a supplement, and psyllium is 🟢 as a substitute rather than a first move (Ch 16).

Part III — Micronutrients

⚠️ Ch 13, A4 — Which supplements survive?

⚠️ Against the short list in Appendix A and the grades in Appendix H, most stacks reduce to zero to two items.

⚠️ The question that does the work is not "is this good for me?" but "do I have the DIAGNOSED condition it is indicated for?" ⚠️ Walt's nine became two.

Part IV — Myths and Debates

⚠️ Ch 17, A1 — Classify these myths

⚠️ Most will land in "over-extension of something real" rather than "fabricated," and if your classification says otherwise, check it against Chapter 17's twenty-four-row interlude.

⚠️ Of the twenty-four retired myths that chapter examined, only six were ❌ outright.

⚠️ Ch 18, A3 — Is this dose or presence?

⚠️ The test: would the claim change if the quantity were a hundredth of what it is?

⚠️ If yes, it is a dose question. If the claimant says no, they are arguing presence, and Chapter 20 §20.3 is the template — organic farming uses pesticides, and the argument was never really about that.

Part V — Life Stages and Goals

⚠️ Ch 23, A2 — Rank the athlete's priorities

⚠️ Energy availability → total macronutrients → timing → supplements.

⚠️ And Chapter 23's observation: attention runs in exactly the reverse order. ⚠️ An athlete worrying about creatine timing while under-fuelled has the hierarchy upside down, and Chapter 34 §34.6 explains what that costs.

⚠️ Ch 26, A1 — Which conditions respond to diet, and how much?

⚠️ Chapter 26's four tiers. A good answer distinguishes:

⚠️ Conditions where diet is a primary treatment (coeliac, PKU, some IBS) · where it substantially modifies course (type 2 diabetes, CVD risk, hypertension) · where it helps at the margin · and where the claim is aspirational.

⚠️ The common error is treating tier 2 as tier 1 — which is how "reverse your disease with food" books get written.

Part VI — Practical Nutrition

⚠️ Ch 30, A2 — Decode two products

⚠️ A correct answer uses, in order: the ingredients list (descending by weight) · QUID percentages · kcal per 100 g · and only then the front of pack.

⚠️ If your comparison used the front-of-pack claims first, reread §30.7 — provenance and quantity are different questions and the front of pack answers neither.

⚠️ Ch 31, A1 — Diagnose the failing plan

⚠️ All four failure modes are present in that plan. Three new recipes on consecutive weeknights · no ZERO night · no fallback · and seven unrelated recipes sharing no ingredients.

⚠️ The rewrite that works: bad-night meal on the Friday they are out, the cook-once meal on Saturday, assembly on Sunday, repertoire meals in the middle, one new recipe on Saturday.

⚠️ What you did NOT have to change: the food. ⚠️ Kwabena's rebuild used the same ingredients and five more minutes of total cooking.

⚠️ Ch 32, A3 — The meat lever

⚠️ Halving meat and doubling pulses in dishes that already contain both cuts per-serving cost by roughly a third to a half, raises fibre, and is close to undetectable.

⚠️ The Ortiz-Lindqvist audit found this was the single largest recoverable line: about $23 a week from one category.

⚠️ Ch 33, A1 — Sort by system

⚠️ (d) is the one that matters. If you sorted it with (b) or (c), reread §33.6 — the tools for those make it worse.

⚠️ Ch 35, A2 — Score a product

⚠️ Most products score zero or one of §35.11's six criteria. ⚠️ The one nearly all of them fail is "compared against BEST CONVENTIONAL ADVICE" — comparison against no advice tests attention, not personalization.

⚠️ Ch 36, A1 — The denominator hunt

⚠️ A correct answer identifies the denominator, notes whether it was stated, and asks who benefits from that choice.

⚠️ Per-calorie flatters sugar and oils and punishes vegetables; per-kilogram flatters anything mostly water; per-protein punishes foods nobody eats for protein.

⚠️ If the comparison is per SERVING and the serving size was chosen by the party making the comparison, that is Chapter 30 §30.5's problem in a sustainability report.

Part VII — Synthesis

⚠️ Ch 37, A1 — The six-question check, live

⚠️ Expect most claims to fail at question 1. ⚠️ Theo's log: 14 of 31 at rung alone, 6 at comparison, 5 at replaces-or-adjusts.

⚠️ If nothing you tested failed, you are either extremely well-sourced or the check is not being applied strictly. ⚠️ If everything failed, check §38.9b's warning about a filter becoming a wall.

⚠️ Ch 38, A1 — The framework

⚠️ There is no model answer, and there should not be. A copied framework is a list, which is exactly what §38.2 argues is NOT the deliverable.

⚠️ What a good one has: section 5 written in your own words rather than copied · section 6 not blank · two current things rather than eight · and under two pages.

⚠️ Tier 3 — what a good answer contains

⚠️ No answers here, on purpose. Guidance only.

⚠️ Ch 2, S1 (steelman the sceptic). ⚠️ A good answer concedes that nutritional epidemiology's confounding problem is genuinely serious before answering it — and notices that most strong critics still recommend approximately Chapter 37's plate.

⚠️ Ch 22, S2 (the UPF definitional problem). ⚠️ A good answer holds both halves: the classification has real problems AND the ward trial found what it found. Chapter 37 §37.9 flags this as a likely overconfidence.

⚠️ Ch 32, S2 (the weight-advice dilemma). ⚠️ This one is genuinely hard and should not resolve cleanly. A good answer engages both Rukhsana's case and Chapter 26's evidence without abandoning either.

⚠️ Ch 34, S1 (withholding diagnostic criteria). ⚠️ A good answer takes the paternalism objection seriously rather than dismissing it, and notices that the answer may differ by reader.

⚠️ Ch 37, S1 (is "boring" a rationalization?). ⚠️ A good answer identifies which of §37.1's four reasons survives the steelman. ⚠️ The fourth — robustness to being wrong — is the one that does most of the work.

⚠️ Ch 38, S1 and S2 (judge the two debts). ⚠️ There is no defence of the book here. §38.1 concedes its caveat is unresolved and §38.2 raises three problems with its own argument. ⚠️ A good answer decides whether those concessions are sufficient, and "no" is a legitimate conclusion.

⚠️ And Chapter 38 §38.4's question 4 — name the claim you are least confident the author got right — has no answer here for the reason the chapter gives: a book you cannot criticize is a book you have adopted rather than read.