Why you should never shop on an empty stomach
And why your professional decisions suffer from the same biology.
We can probably agree that we make poor decisions in the supermarket when we're hungry or tired. The chocolate, the crisps or the croissant that suddenly ends up in the basket is a classic sign that you're not the one in control. Your biology is.
But at work, thankfully, we're different. At our desks, we lead with a rational, objective mind and make decisions based on pure logic. Right?
Wrong. Whatever your seniority, experience or title, your ability to make good decisions can be "hijacked" by exactly the same biology.
THE MECHANISMYour brain trades quality for convenience
When you've skipped lunch, spent the morning fighting fires or had back-to-back meetings, your brain is in low-power mode. It shuts down the most energy-hungry programmes: complex problem-solving, empathy and strategic perspective.
We stop looking for the best solution and start looking for the quickest relief instead. It often shows up as:
- Short-fused communication: You react hastily or defensively. That quick email or Slack message that later costs you hours clearing up misunderstandings and rebuilding trust.
- Avoidance: You postpone the necessary but demanding conversation or the direct feedback. You buy yourself peace now, but the price is growing frustration and unresolved problems that hit you twice as hard later.
- Mediocre compromises: You approve an "okay" proposal here and now, because your brain doesn't have the energy to demand quality. It saves you time today, but costs you dearly when the overlooked risks become reality.
THE UPGRADECheck your foundation
Before you send the email or make the decision, do this 30-second audit:
- Run a quick check. Am I sure I would make the same choice at 9 am tomorrow after a good night's sleep? If the answer is "maybe", the decision is probably driven by biology, not expertise.
- Restart the system. Is your battery flat? Take a 5-minute break. A walk or a snack isn't a break from work, it's the foundation for good decisions.
- Park the decision until a set time (if you can). Very few choices need to be made this second. Moving the decision to the next morning or sending the email in a few hours isn't hesitation, it's strategic headroom.
THE SCIENCEWhen your mental software is in low-power mode
- Decision fatigue: Every choice drains your battery. By mid-afternoon, the brain automatically prioritises the easy option over the right one (Levav & Danziger, 2011).
- Stress hijacking: Under pressure, the system locks the door to your logical centre, forcing you to run on default code and habits rather than new, creative ideas (Arnsten, 2009).
- The hunger glitch: When blood sugar drops, the brain loses its ability to filter impulses. You stop calculating ROI and start looking for the quickest win (Danziger et al., 2011).
Want to train it with your team? That's exactly what my workshops and talks are about.