Measurement Feedback Loop
Record a meaningful signal and let visible facts guide small corrections
- Difficulty
- Easy
- Time to result
- ~weeks to results
- Steps
- 4
- Confidence
- 97%
The Measurement Feedback Loop begins without prescribing a complete behavior-change plan. Thorp told a relative who wanted to lose weight simply to weigh himself every morning, record the date and number, and observe it day after day. While the relative kept recording, his behavior changed and his weight drifted downward. Thorp used the same practice to keep his own weight within a stable range, making a small food or drink adjustment near the upper boundary. He supplemented the scale with a visual check for abdominal fat. The mechanism is awareness: a repeated factual signal makes drift visible early enough for modest corrections, replacing hopes and wishes with evidence from one's own behavior.
Origin
Thorp developed the approach while helping an overweight relative and then used weight and waist feedback himself for many years.
Core principles
- 01Awareness can change behavior before a detailed intervention
- 02Use facts instead of hopes, beliefs, or wishes
- 03Choose feedback that is easy to observe repeatedly
- 04Make small corrections when the signal nears a boundary
How to run it
- 1
Choose the feedback
Select a simple signal closely related to the outcome you want to influence.
Pro tip Use more than one easy signal when they reveal different risks.
Watch out A convenient metric is not useful if it does not track the underlying concern.
- 2
Record consistently
Write down the date and measurement repeatedly under comparable conditions when possible.
Pro tip Note timing differences so you can interpret an off-schedule measurement.
Watch out Stopping measurement when the result is uncomfortable removes the feedback.
- 3
Watch the boundary
Define a normal range and notice when the signal approaches the edge rather than waiting for a large problem.
Pro tip A stable bracket can be more actionable than pursuing a perfect point target.
- 4
Make a small correction
Choose an immediate behavior that nudges the signal back toward its desired range, then keep observing.
Pro tip Use the least disruptive correction that reliably changes direction.
Watch out Personal tracking does not replace professional medical advice.
In the wild
Thorp's relative repeatedly lost momentum when he stopped writing down his weight. While he recorded it, his behavior shifted and the number slowly moved downward.
→ Measurement itself created useful awareness even before a prescribed diet plan.
Thorp says he stayed between about 151 and 158 pounds. Near 158, he might skip dessert or beer or choose a large healthy salad instead of a burger.
→ An upper boundary triggered small corrections before weight drift became large.
Common mistakes
Tracking without a response boundary
A number becomes more useful when it is linked to a clear corrective action.
Demanding perfect measurement conditions
Thorp sometimes weighed later in the day and interpreted the difference rather than abandoning the feedback.
Is it for you?
Best for
Habits with a meaningful, repeatable signal and small actions that can change its direction.
Not ideal for
Complex medical decisions where one personal metric cannot establish cause or safety.
From the transcript
“The first thing you do is you get on the scale every morning, and you write down the date, and how much you weigh.”
“Those two feedbacks are more than enough to control my weight for a lifetime and I really have to use them.”
“And measurement is important because you want facts on which to base what you do instead of hopes, beliefs, wishes, so on.”
From the episode
#604: Master Investor Ed Thorp on How to Think for Yourself, Mental Models for the Second Half of Life, How to Be Inner-Directed, How Basic Numeracy Is a Superpower, and The Dangers of Investing Fads
Ed Thorp