This is the index for all CRON content on Cast in Iron. Roy Walford’s Calorie Restriction with Optimal Nutrition framework is the structural foundation for every recipe, meal plan, and protocol on this site.

Start with the explainer if you are new to CRON. Go deeper with the philosophy or the science. Use the menus and plans to put it into practice.

Start Here

What Is the CRON Diet? The foundational explainer. What CRON stands for, the core principle, what a full day of CRON food looks like, what gets excluded and why, and how to start. If you read one page on this site, read this one.

CRON Diet Menu: Sample Weekly Meal Plans Three weeks of menus with exact macros and micronutrient coverage. Monday through Sunday, breakfast through dinner. Includes a 1,800-cal baseline, a 2,100-cal higher-training variation, and a sardine rotation week.

The 7-Day CRON Starter Plan — $15 One fully assembled week. Grocery list, batch timing, Cronometer setup guide, and the 5 mistakes that derail most first attempts. The entry point before committing to the full 30-day protocol.

The Science and Philosophy

The CRON Nutrition Philosophy The deeper framework: why these 8 micronutrients, why the nutritional floor matters, why CRON is a permanent system and not a diet phase. Includes the full breakdown of the 13 tracked nutrients.

Roy Walford — The Man Behind the Protocol UCLA pathologist, Biosphere 2 resident, author of The 120 Year Diet. The research behind the framework and why it came from a bench scientist, not a wellness brand.

CRON vs. IIFYM vs. Keto What each framework tracks and what it misses. IIFYM tracks macros. Keto tracks carbs. CRON tracks macros, 8 micronutrients, and anti-nutrient interference. Side-by-side comparison with data.

Meal Plans and Menus

The 30-Day CRON Meal Plan — $49 28 days fully assembled. Daily macro and micro totals across 13 nutrients, weekly grocery lists with estimated costs, batch timing sequences, alternative protein swap guide, and eating-out survival guide.

The CRON Ingredient Legend Every functional ingredient on this site — nutritional yeast, dulse, miso, kombu, shiitake, spirulina — what each one does, how much it contributes, and how to use it. Reference guide for building CRON-compliant meals from scratch.

The Batch Cooking System The operational layer. How to batch cook four proteins, two vegetables, and four sauces in three hours on Sunday. The same system that underlies both the 7-day and 30-day plans.

Alternative Proteins for Longevity Eight protein sources selected for micronutrient density — not just grams of protein per serving. Swap guide with nutrient impact notes.

The Excluded Foods

Low-Oxalate Eating: What the Research Actually Shows Why spinach, beets, almonds, and sweet potatoes in quantity are absent from CRON menus. Oxalic acid binds iron, zinc, calcium, and magnesium in the gut and prevents absorption. The research and the replacements.

Why We Dropped Spinach The specific case against spinach as a “health food.” 750-1,145 mg oxalate per 100g. If you are eating spinach for iron, you are getting negligible amounts of it.

Supporting Protocols

Blood Work Guide for Men Over 40 The baseline you need before starting any serious calorie restriction protocol. What markers to track, what ranges to target, and what low-normal results actually mean.

Zinc and Magnesium: Fix the Inputs First The two micronutrients men in a caloric deficit are most commonly deficient in. How CRON addresses both from food rather than supplementation.

No TRT. No GLP-1. Fix the Inputs First. The philosophical foundation behind the site. Calorie restriction with optimal nutrition as a first-line intervention before pharmaceutical tools.

CRON Recipes

Every recipe on this site is built to CRON standards: 30g+ protein per serving, micronutrient anchors in every meal, no high-oxalate ingredients. A selection of the core CRON recipes:

All CRON recipes →

The Foundation

The CRON framework rests on a single finding from 35 years of animal and human research: organisms that eat fewer calories live longer — but only when those calories are nutrient-dense enough to prevent deficiency.

Cut calories without covering your micronutrients and you get a malnourished organism that declines faster, not slower.

Every meal on this site is an attempt to solve that problem with food that is worth eating.