#173 - AMA #26: Continuous glucose monitors, zone 2 training, and a framework for interventions

Aug 23, 2021 Episode Page ↗
Overview

Peter Attia and Bob Kaplan discuss follow-up questions on CGM and Zone 2 exercise, including a foundational framework for evaluating interventions. They also touch on Tour de France physiology and the behavioral impact of monitoring tools.

At a Glance
7 Insights
19m 39s Duration
7 Topics
2 Concepts

Deep Dive Analysis

Introduction to AMA 26: CGM and Zone 2 Follow-ups

Peter's Foundational Framework for Evaluating Interventions

Applying the Framework to Continuous Glucose Monitors (CGM)

Potential Harms and Benefits of CGM Use

Economic and Opportunity Costs of CGM

CGM as a Tool for Insight and Behavioral Change

Impact of Different Fruits on Glucose Spikes

Peter's Framework for Interventions

A structured approach to evaluate any intervention by asking three core questions: what is the risk of harm, what is the probability of benefit, and what is the opportunity cost. This framework is especially useful when rigorous randomized controlled trials (RCTs) are not available.

Hawthorne Effect (Behavioral Good)

The phenomenon where individuals modify an aspect of their behavior in response to their awareness of being observed or monitored. In the context of CGM, simply wearing the device and monitoring glucose can lead to improved dietary choices and habits due to this effect.

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What is Peter's foundational framework for considering different interventions?

Peter's framework involves asking three questions: what is the risk of harm, what is the probability of benefit, and what is the opportunity cost of the intervention.

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How does Peter apply his framework to the use of Continuous Glucose Monitors (CGMs) in non-diabetics?

He considers the risk of harm to be very low (primarily anxiety/obsession), the probability of benefit to be ample (insight into carbohydrate tolerance and behavioral modification), and the opportunity cost to be mainly economic.

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Can wearing a CGM be harmful?

The most obvious potential harm is the anxiety and obsession it can stoke, particularly in individuals with a history of eating disorders, for whom Peter would not recommend its use.

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How does wearing a CGM help change behavior?

It functions as a monitoring tool, similar to a food diary, leveraging the Hawthorne effect where the act of monitoring one's food intake or glucose levels leads to making better choices.

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What is the typical shift in benefit from CGM use over time?

Initially, the benefit is about 90% insight and 10% behavioral change, but within approximately three months, this ratio flips, with behavioral modification and gamification becoming the primary benefits as initial insights are gained.

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Why do some fruits cause glucose spikes while others don't?

The transcript cuts off before a full answer is provided to this question.

1. Apply 3-Question Intervention Framework

Evaluate any new intervention by asking three critical questions: What is the risk of harm, what is the probability of benefit, and what is the opportunity cost (financial, time, or sacrificing other beneficial activities)? This framework helps in making informed decisions, especially when clear scientific evidence like RCTs is lacking.

2. Utilize Monitoring for Behavior Change

Employ monitoring tools, such as a food diary or a Continuous Glucose Monitor (CGM), to track your intake or behavior. The act of monitoring itself creates accountability and can lead to immediate, positive changes in behavior and choices, leveraging the Hawthorne effect to your advantage.

3. Consider a 3-Month CGM Trial

If you do not have contraindications like a history of eating disorders, consider undertaking a three-month trial of Continuous Glucose Monitoring (CGM). This initial period is highly insightful for understanding your body’s unique responses to food and activity.

4. Gain Carb Tolerance from CGM

Use a Continuous Glucose Monitor (CGM) to gain insight into your personal carbohydrate tolerance. The device is specifically designed to teach you how your body responds to different carbohydrate sources and quantities.

5. Understand CGM Value Shift

Expect the value derived from CGM use to shift over time; initially, it will be about 90% insight and 10% behavior change, but within approximately three months, this will flip, with the CGM primarily serving as a behavioral tool for accountability and gamification.

6. Use CGM Periodically

Rather than continuous use, consider using a Continuous Glucose Monitor (CGM) periodically to gain insights. You don’t need to be tethered to it every minute of every day to extract significant value, especially given its economic cost for non-diabetics.

7. Avoid CGM with Eating Disorders

Do not advocate the use of Continuous Glucose Monitors (CGM) for individuals with a history of eating disorders. For these patients, CGM can become another tool that fuels a negative cycle of obsession.

What is the risk of harm from doing this thing?

Peter Attia

What's the opportunity cost of this intervention?

Peter Attia

I think everybody deserves a three-month trial of CGM.

Peter Attia

I've been wearing CGM for almost six years. It never gets old to me. I continue to find insights that just provide value.

Peter Attia

If I said to you, Bob, I want you to record everything you eat for the next month and track it in a food diary, are you going to make better food choices than you are making now? And the answer is unequivocally, yes, you are going to do that.

Peter Attia

Peter's Framework for Evaluating Interventions

Peter Attia
  1. Ask: What is the risk of harm from doing this thing?
  2. Ask: What is the probability of benefit from doing this thing?
  3. Ask: What is the opportunity cost of this intervention?
~$10
Daily cost of CGM (without insurance) Directionally speaking, for non-diabetics not covered by insurance.
~$3,500
Annual cost of CGM (without insurance) If worn continuously by a non-diabetic not covered by insurance.
3 months (90 days)
Recommended trial duration for CGM For non-diabetics to gain significant insight into carbohydrate tolerance.
90% insight, 10% behavioral change
Initial split of CGM benefit Within the first three months of use.
The ratio flips
Long-term split of CGM benefit After about three months, behavioral change becomes more dominant than new insights.
~$1,000
Cost of a specific 'trance' device An example device discussed for its opportunity cost.
Two 20-minute sessions (40 minutes total)
Recommended daily use for a specific 'trance' device As prescribed by the company for the 'trance' device.