Chapter 7 — Key Takeaways
One page. The reference card for every carbohydrate argument you'll ever have.
Retire This
"Simple versus complex." It classifies by molecular chain length when what matters is structure. White bread and lentils are both "complex" and behave nothing alike; an apple is "simple" and behaves better than both.
Use This Instead
The question is never "is this a carb?" It's "how much structure is still around it?"
| Intact | Refined | |
|---|---|---|
| Examples | Whole grains, legumes, whole fruit, potato with skin, steel-cut oats | White flour, white rice, juice, most cereal, syrups |
| Digestion | Slower — enzymes must get past structure | Fast — structure already removed |
| Fiber, micronutrients | Present | Largely stripped |
| Satiety per calorie | Higher | Lower |
| Energy density | Lower | Higher |
| How fast you can eat it | Slowly | Very fast |
300 kcal of apples = 3 apples, 15–20 min of chewing. 300 kcal of juice = 600 ml, 2 minutes. Same category, same energy, completely different outcome.
And it's a continuum, not a binary. Oat groats → steel-cut → rolled → instant: nothing subtracted at any step, glucose response changes anyway, purely from particle size.
Glycemic Index — a good tool, a poor system
Five problems: measured alone and fasted (nobody eats that way) · values unstable across variety, ripeness, cooking, and laboratory · individual variation is large · low GI ≠ healthy (ice cream beats potato) · outcome evidence is modest.
Glycemic load (GI × g carbohydrate ÷ 100) is the better number, because portion matters.
If you're looking up a GI value before eating, the intact/refined question would have gotten you there faster.
How Much Do You Need? Three layers
| Layer | Figure | What it means |
|---|---|---|
| Strict biochemical requirement | ≈ zero | Gluconeogenesis + ketones cover it — but the cost is paid in protein (Ch 6) |
| RDA | 130 g/day | The amount that removes the need to manufacture glucose. Not a survival threshold. |
| AMDR | 45–65% of energy | A population range, deliberately wide. Not a prescription. |
There is no optimum. Populations have thrived from ~5% to over 80% of energy as carbohydrate. Anyone giving you a single number is giving you a preference.
Blood Sugar "Spikes"
In a healthy person, a post-meal rise is physiology, not pathology — it's what insulin is for. Typical: fasting 70–99 mg/dL, peak below ~140, back toward baseline in 2–3 hours.
What matters is failure to clear, not the excursion: rising fasting glucose, creeping HbA1c (prediabetes 5.7–6.4%), prolonged elevations. That's insulin resistance, and it's Chapter 26.
The History, in Two Lines
The low-fat era failed because of what replaced the fat — sugar and refined starch. The low-carb era succeeds, where it does, because of what gets replaced when carbohydrate goes — sugary drinks, refined snacks, ultra-processed food.
Neither era was ever about a macronutrient. Both were about substitution — Chapter 2, wearing a hat.
What to Actually Do
- Prioritize intact over refined. This is the whole chapter.
- Drink fewer calories. Sugar-sweetened beverages are the strongest negative evidence in the category. If you change one thing, change this.
- Eat legumes. Cheap, filling, high-fiber, high-protein, and most people eat almost none.
- Don't fear fruit. Whole fruit comes with structure. The fructose argument applies to liquid and refined sources.
- Match intake to activity. Neither high nor low is a moral position.
- Stop optimizing GI and stop chasing a flat curve unless you have diabetes or prediabetes.
Reading the Label (§7.12)
- Read Added Sugars, not Total Sugars. Milk and fruit show sugar without anything being added.
- Fiber ≥ 3 g per serving on a grain product suggests genuinely closer to intact.
- First ingredient: "whole wheat flour" first means something; "enriched wheat flour" first doesn't.
- Ignore "net carbs." No legal definition, inconsistent method, and maltitol gets subtracted in full despite being absorbed.
"Whole grain" tells you a subtraction didn't happen. It says nothing about grinding or addition — which is where most of the difference lives.
Common Mistakes (and the fix)
| Mistake | Fix |
|---|---|
| "Rice digests to glucose so it's basically sugar" | Chemically similar, nutritionally different — structure, fiber, satiety, and what it's eaten with |
| Organizing meals around GI | Use intact vs. refined; it's simpler and captures most of it |
| Avoiding whole fruit over fructose | Whole fruit has structure. Liquid and refined sources are the issue. |
| Assuming "whole grain" = minimally processed | It's a claim about subtraction only |
| Cutting a cheap cultural staple with no clinical indication | Do the ledger — money, time, and whether the household will eat it |
| Fearing normal post-meal glucose rises | That's insulin working |
| Believing the resistant starch "hack" is large | Real, reproducible, a few percent |
Verdict Summary
| Claim | Verdict | Why |
|---|---|---|
| GI tells you which carbs are healthy | 🟡 Unclear / it depends | Real clinical tool; poor everyday system — unstable, isolated measurement, low GI ≠ healthy |
| Blood sugar spikes harm metabolically healthy people | 🟡 Unclear / it depends | Matters in diabetes; no outcome evidence for flattening curves in the healthy |
| Carbohydrates make you fat | 🟠 Probably false | Controlled trials find little difference; the real effect is refined form and eating rate |
| Whole grains are no better than white bread (phytates, lectins) | ❌ Not supported | Real chemistry, addressed by cooking; outcome evidence goes firmly the other way |
| Erythritol causes heart attacks and strokes | 🟡 Unclear / it depends | Real study, high-risk cohort, heavy confounding, endogenous production. Genuinely unsettled. |
⚠️ When to See a Professional
Symptoms of high blood glucose — excessive thirst, frequent urination, unexplained weight loss, blurred vision, recurrent infections, slow healing — warrant a physician, not a monitor. Diagnosis uses HbA1c, fasting glucose, or an OGTT, not a consumer CGM, and a consumer device should never be used to self-diagnose or to adjust diabetes medication.
One Thing to Remember
The category "carbohydrate" contains lentils and Coca-Cola. Any claim about the category has told you nothing. Ask about the structure instead.