Carb Timing and the 1-Week Rule

Justin Harris
6 min read
troponiniq
blog
coaching

Why small nutrition changes should wait for the next signal, not the next feeling.

Carb Timing and the 1-Week Rule

Why small nutrition changes should wait for the next signal, not the next feeling.

The Joe Webb check-in shows the core problem plainly: the same insulin dose that worked one week earlier started dipping blood sugar on a high day, and the fix was not a wholesale rewrite but a 1 iu reduction and moving the next meal 30 minutes sooner. That is a timing problem, not a panic problem, and the mechanism is simple: short-term sensitivity shifts can make yesterday’s nutrition plan wrong today. The falsifiable thesis is this: in coaching, most nutrition adjustments should be delayed until the next repeatable signal appears, then changed in one small step, because immediate over-adjustment creates more noise than progress.

That sounds conservative, but it is actually how the best coaching reads the map. The client did not report a new physiology overnight so much as a changed response on a specific day: the same dosing pattern produced a noticeably earlier glucose dip, then a smaller dose worked once, then the same reduced dose did not fully solve it on the next shot. The useful takeaway is not “be aggressive.” It is that nutrition timing matters enough that you should treat a single day as a data point, not a verdict.

This is where AI coaching is most likely to become unhelpful. A model sees a message like “my blood sugar dipped” and wants to propose a clean solution immediately: cut carbs, move meals, add a rule, or call the whole setup broken. Human coaching in the KB does the opposite. It asks whether the change is part of the expected transition, whether it has happened on more than one repeatable occasion, and whether the smallest fix restores the pattern without breaking the day. That is a better decision process for any plan that depends on timing—high days, meal spacing, pre/post-workout food, or any setup where one variable can dominate the others.

The nutrition lesson is not limited to insulin. In the deep nutrition notes, Justin’s guidance on fruit and carb source shows the same structure. He does not obsess over whether a banana versus blueberries changes the outcome in some magical way. He says he would be surprised if you saw a noticeable difference over a year even if you did all your carbs as fruit, because the vast majority of results come from nailing macros. The exception is not that details never matter; it is that they matter in the final percent, not in the first move. On pre- and post-workout meals, fruit is fine up to about 50% of the carbs with no downside. On medium days, fruit is fine in other meals too, as long as it is not every meal and at least half the carbs per meal come from more complex sources. On high days, carb load is so high and insulin elevated all day that sugar barely matters and fruit mainly helps keep food volume down.

That framework is useful because it separates two kinds of coaching decisions: the big lever and the adjustment lever. The big lever is total intake and macro structure. The adjustment lever is the timing detail that smooths execution. Too many coaches use the adjustment lever like a big lever and end up making a plan fragile. Change too much at once and you no longer know which change mattered. That is especially dangerous when the athlete is already dealing with moving inputs—travel, illness, fatigue, appetite changes, or training stress.

The Rory Lazowski thread on retatrutide makes the same point from a different angle. Justin notes that the compound is definitely lowering appetite and that he is not sure he likes the idea of forcing appetite lower. He also says that if food is going to increase, he may give the dose a pause or reduce it until prep. That is a timing decision, not a permanence decision. He is not trying to freeze the athlete in a forever state; he is matching the appetite effect to the phase. Then he adds the part most people skip: he wants more data before deciding whether it is actually helpful for gaining at smaller doses. In other words, he is not letting one strong early signal become a doctrine.

That restraint matters because appetite, fullness, and fatigue are all easy to over-interpret. The first appetite drop may feel dramatic. The first fatigue bump may feel like a verdict. But if the phase is about adding food, the right response is often to wait for the next data point or make a small phase-matched change, not to re-engineer the whole setup. In coaching terms: if you changed intake today and the body reacted today, do not immediately stack a second change unless the first one created a clear operational problem.

This is the practical anti-hype position on AI fitness coaching. AI is very good at producing a plausible answer instantly. It is much worse at respecting the lag between a change and its meaning. Human coaching, at least in the examples here, is built around that lag. Joe’s high-day insulin issue was handled by reducing the dose modestly and moving the next meal earlier. Fruit timing was adjusted by day type and meal context, not by banning an ingredient. Retatrutide was viewed through phase and appetite response, not through a universal “good/bad” label.

For coaches, the rule is simple enough to operationalize:

  1. Identify the day-type or phase before changing anything.
  2. Ask whether the problem repeated in a comparable setting.
  3. Make the smallest change that restores execution.
  4. Hold that change long enough to see whether it actually worked.
  5. Do not layer on a second fix until the first one has had time to show its effect.

That last step is the one most people miss. The temptation is always to improve the plan immediately. But immediate improvement is often just disguised churn. The athlete feels heard, the app looks busy, and the plan becomes impossible to interpret. In contrast, a one-step correction preserves the signal. If the change works, you keep it. If it does not, you now know something useful. If the athlete is in a phase where food is moving anyway, you keep the adjustment small until the next repeated pattern tells you otherwise.

So the evidence-aware coaching position is not “make fewer changes because change is bad.” It is “make changes when the signal repeats, and make them small enough that you can still tell what happened.” That is the difference between a coach who manages a plan and a coach—or AI system—that merely reacts to it.

Sources Used

  • modules/08-voice/kahunas-coaching-deep-voice.md
  • modules/03-knowledge/kahunas-coaching-deep-nutrition.md
  • raw/_consumed/2026-05-31/kahunas-export/2026-05-31-w13-18m/transcripts/joe_webb___members-rksigkykimaxwmo_t4_e8nwvbtc2j0etleutkyysads.md
  • raw/_consumed/2026-05-31/kahunas-export/2026-05-31-w13-18m/transcripts/rory_lazowski___members-c5balaovjbdoeefqmfuqdhh2tbpmfdu16lnf0tnrtmw.md

Sources Used

  • /Users/justinharris/TroponinIQ/kb/supertrop/modules/08-voice/kahunas-coaching-deep-voice.md
  • /Users/justinharris/TroponinIQ/kb/supertrop/raw/_consumed/2026-05-31/kahunas-export/2026-05-31-w13-18m/transcripts/rory_lazowski___members-c5balaovjbdoeefqmfuqdhh2tbpmfdu16lnf0tnrtmw.md
  • /Users/justinharris/TroponinIQ/kb/supertrop/modules/03-knowledge/kahunas-coaching-deep-nutrition.md
  • /Users/justinharris/TroponinIQ/kb/supertrop/raw/_consumed/2026-05-31/kahunas-export/2026-05-31-w13-18m/transcripts/joe_webb___members-rksigkykimaxwmo_t4_e8nwvbtc2j0etleutkyysads.md