September 28, 2026

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Hi Everyone,

What you eat during a work day, and when, changes how clearly you think for the rest of it.

Today we're sharing an eating plan that puts your meals, your caffeine, and your hardest work in the right order across a 12-hour day, plus a one-page template you can fill in for your own schedule.

The plan, hour by hour

The sample below is for someone who wakes at 6:30 and goes to bed at 10:30. Shift the times to fit your own day.

7:00 First coffee, one normal cup. Military researchers who study people working through the night recommend caffeine in smaller repeated doses rather than one large dose taken early.

7:30 Breakfast is your call. Across dozens of studies, adults who skipped it thought just as clearly through the morning as adults who ate it. Skip it, keep it — either works.

9:00 The hardest work starts here. The pricing decision, the negotiation, the difficult conversation with a direct report. Everything that needs your best judgment happens before lunch.

10:30 Second coffee, and the last one of the morning.

12:30 Lunch, at half the size you would normally order. Mostly protein and vegetables, with a small portion of starch.

1:30 to 3:00 The slow part of the afternoon. Fill it with emails, routine calls, or a walk, and keep decisions out of it.

3:00 Last caffeine of the day, if you want it. As we covered in our jet lag issue, caffeine even six hours before bed measurably reduces sleep, and sleeping less tonight hurts tomorrow's thinking.

Dinner: Eat as usual. This plan only covers working hours.

Two things people get wrong about lunch

It’s common knowledge that a heavy lunch slows the afternoon down. Here are two things you might not know already:

1. The post-lunch slump arrives even if you skip lunch. It follows your body clock, so eating nothing doesn't prevent it.
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2. The low-carb lunch doesn't prevent it either. In one experiment, lunches unusually heavy in fat slowed reaction times just as much as lunches heavy in carbohydrate. The balanced plate beat both.

And the bigger the lunch, the bigger the impact. In a driving experiment, a heavy lunch of around 900 calories made people measurably worse at keeping the car in its lane for the rest of a two-hour drive. A light lunch a third of the size did not.

What about client lunches?

You can't always choose the restaurant, and sometimes the lunch is the meeting. You can still choose your order: whatever's mostly protein and vegetables on that menu, and skip the bread and the dessert.

And when a heavy lunch is unavoidable, change the afternoon instead. Move whatever needs your best judgment to before noon or after 3:30, and put email and routine calls in the 90 minutes after eating.

Try it this week

We've turned the schedule above into a one-page template with blank fields for your wake time, lunch time, and caffeine cutoff; download it here.

Then move one decision meeting out of the 90 minutes after your usual lunch.

After a week, compare those afternoons with your usual ones. If the meetings went better, move the rest.
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Download the 12-hour eating plan

Go deeper

👉 U.S. Army: Study points to fats, carbs as 'brain food' — read this before assuming protein is the focus food; in flight-simulator tests, pilots eating high-protein diets flew worst.

👉 American Academy of Sleep Medicine: Late afternoon and early evening caffeine can disrupt sleep — use it to set your own afternoon caffeine cutoff; even a dose six hours before bed cut total sleep time by more than an hour.

👉 Nature Metabolism: Postprandial glycaemic dips predict appetite and energy intake — read this if you want the mechanism behind the afternoon drop; people with the biggest post-lunch glucose dips ate 312 extra calories a day.

👉 University of Auckland: Does fasting dull your mental edge? — read this if you've ever worried that skipping breakfast costs you focus; the researcher behind the biggest analysis on it explains why it doesn't.

Coming up tomorrow

Tomorrow we’ll look at how to explain a bad quarter to your board without making excuses or losing their confidence.

Have a great week!

P.S. If you run this plan for a week, reply and let us know what changed.
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