Fasting Topic Guide

Curated clips, articles, and podcast episodes

The term fasting covers a wide spectrum of dietary strategies, from time-restricted eating and intermittent fasting to prolonged water-only fasting and fasting-mimicking diets. The proposed benefits of fasting range from weight loss and metabolic health to cellular repair, disease risk, and longevity—but the evidence behind these claims varies considerably, and much remains unsettled.

This guide explores the definitions, mechanisms, and evidence surrounding fasting, with an emphasis on separating hype from data and understanding when and how fasting may be useful—or harmful.

Foundations & Definitions

This section defines fasting and distinguishes it from related approaches like caloric restriction. It explores the most common fasting protocols, how they are structured, and why someone might choose fasting over continuous energy restriction. It also addresses key practical questions such as timing of eating windows and how different fasting strategies are applied in both research and clinical settings.

Topic Guides

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Fasting Topic Guide

Curated clips, articles, and podcast episodes

Defining fasting and how it fits in the framework of dietary restriction

The most common types of fasting

Why someone might choose fasting over continuous caloric restriction

Defining the various fasting protocols

What do we know about the optimal protocol, frequency, and duration for fasting?

Time-restricted eating as the gateway to fasting

When intermittent fasting, does the placement of the feeding window matter?

Time-restricted feeding and intermittent fasting

The effect of caloric restriction on the hallmarks of aging

Comparing the physiological effects of a ketogenic diet to those of long-term fasting

What do we know about fasting, ketosis, and autophagy?

Nutritional ketosis defined

Insulin, weight gain, and using fasting to deplete the cells of glucose

Fasting observations: Core body temperature and thyroid hormone

Fasting observations: Glucose, BHB, and hunger levels

Examining the evidence for the long-term health benefits of fasting beyond short-term metabolic effects

Exploring whether prolonged fasting can reduce cancer risk

Evaluating fasting's role in health

How extended fasting compares to caloric restriction in improving insulin sensitivity in people

Examining whether fasting improves cardiovascular disease risk

Exploring fasting as a tool for longevity

Examining various fasting methods for autoimmune diseases

Examining fasting for protection against neurodegenerative diseases

Fasting and gut disorders

Is there any evidence that fasting can extend lifespan?

The common health claims associated with fasting across metabolic health

The impact of fasting on body weight and body composition

Weight loss strategies, tracking calories, cheat meals, snacks, fasting, exercise, and more

Where Layne has changed his views on fasting

Latest insights on fasting, Alzheimer’s disease, cancer, exercise, and nutrition

Comparing bariatric surgery to fasting as a treatment for Type 2 Diabetes

A practical framework for using fasting as a strategy to improve body composition

The primary risks and downsides associated with fasting

Weight regain and potential metabolic consequences of fasting

The risk of lean mass loss with fasting and how to mitigate it

How fasting and calorie restriction affect muscle mass and what can be done to minimize muscle loss

Who should avoid fasting and why

The essential vitamins and minerals to supplement during prolonged fasting

Body composition, protein, time-restricted feeding, fasting, DEXA scans, and more

Examining fasting as a tool for cognitive enhancement

Fasting and Type 1 Diabetes

Evaluating differences between men and women in their ability to fast

Exploring CGM insights into the depth of a fast

Importance of community support while fasting

Peter's exercise regimen during a fast

Peter's hunger levels during a typical 7-day fast

Peters' sleep protocol during a fast

Peter's supplement protocol during fasting and why he eats a ketogenic diet leading up to a prolonged fast

Does fasting cause gallstones?

Muscle loss during fasting

Why do people think that fasting is bad for you?

Can extreme calorie restriction enhance human lifespan?

Does time-restricted eating increase the risk of cardiovascular death?

Does skipping breakfast increase the risk of an early death? Part I

Does skipping breakfast increase the risk of an early death? Part II

Is alternate-day fasting superior to calorie restriction for fat loss in lean adults?

Time-restricted eating: efficacy versus effectiveness

Intermittent fasting

Can fasting help athletes hold their breath longer?

Alternate Day Fasting

Can you maintain muscle during fasting?

Can you preserve lean body mass during “semi-starvation?”

Fasting and cancer

Fast-breaking without glucose spiking

Is there an optimal window of time-restricted feeding?

Ketones, fasting, and muscle loss

Fasting and conserving energy

The ketogenic diet, ketosis, and hyperbaric oxygen: metabolic therapies for weight loss, cognitive enhancement, cancer, Alzheimer’s disease, brain injuries, and more

Fasting: benefits for body composition and disease prevention, potential risks, and Peter’s updated practical framework

Building strength and muscle mass: how to optimize training, nutrition, and more for longevity

Metabolism, energy balance, and aging: How diet, calorie restriction, and macronutrients influence longevity and metabolic health

Special episode: Peter on exercise, fasting, nutrition, stem cells, geroprotective drugs, and more — promising interventions or just noise?

Latest insights on Alzheimer’s disease, cancer, exercise, nutrition, and fasting

Peter’s historical changes in body composition with his evolving dietary, fasting, and training protocols

Training principles for mass and strength, changing views on nutrition, creatine supplementation, and more

Body composition, protein, time-restricted feeding, fasting, DEXA scans, and more

Energy balance, nutrition, & building muscle

Fasting as a potent antidote to obesity, insulin resistance, type 2 diabetes, and the many symptoms of metabolic illness