Can agents run this deterministically?

Yes. Supply protocol, first_meal_time, and optional fast_days as JSON to receive eating/fasting windows and day-based guidance deterministically.

Nutrition

Intermittent Fasting Window Planner

Plan your intermittent fasting schedule with protocol-specific eating and fasting windows, daily timelines, and 5:2 fast-day planning.

Daily Window Plan

Eating window

12:00 PM to 8:00 PM

Fasting window

16h

8:00 PM to 12:00 PM (+1d)

24-Hour Fasting Schedule

Eating and fasting blocks are mapped onto a single day so the protocol is easy to follow.

Eating window

12:00 PM -> 8:00 PM

Fasting window

8:00 PM -> 12:00 PM (+1d)

16h

Fasting window (next day)

8:00 PM -> 12:00 PM (+1d)

wrap

00:0024:00

24-hour timeline

16:8

EatingFasting

16:8: eat between 12:00 PM and 8:00 PM, fast for 16 hours. Fit 3 meals in the window. Start with 16:8 if you are new to fasting. Keep meal timing consistent for 1-2 weeks before tightening the window.

Meal schedule

Meal 1 — 12:00 PM

Meal 2 — 4:00 PM

Meal 3 — 7:45 PM

Stay on schedule

Zero Fasting App

Timer and tracking for all IF protocols

→

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General fitness estimates — not medical advice.

How to use it

Enter your preferred eating window length and first meal time. Common protocols: 16:8 (16h fast, 8h eat), 18:6, 20:4. Longer fasting windows improve compliance for some people but do not inherently improve fat loss at equivalent calories.
IF does not accelerate fat loss beyond equivalent calorie restriction without time restriction. It works because some people find it easier to skip breakfast than to reduce portion sizes — compliance is the primary mechanism.
Hunger adapts to your eating schedule within 7–14 days. Significant hunger in the first week is normal and largely resolves as ghrelin rhythm adapts to the new meal timing.
Protein target must be hit within the eating window regardless of IF protocol. Compressing all meals into 6–8 hours makes it harder to distribute protein for optimal muscle protein synthesis — track protein specifically during IF.
Coffee, tea, and water do not break a metabolic fast and meaningfully reduce hunger during the fasting window. Cream or milk above 20 calories will partially break a strict fast.

AI Integrations

Contract, discovery endpoints, and developer notes for agent use.

Always available for agents

Tool contract JSON

https://aifithub.io/contracts/intermittent-fasting-window-planner.json

Stable input and output contract for this exact tool.

Human review

People can use the browser page to sense-check outputs and charts, but agents should still execute against the contract and discovery endpoints.

/agent-tools.json - machine-readable tool index.
/llms.txt - human-readable model discovery guide.
/.well-known/webmcp.json - WebMCP capabilities manifest.
/.well-known/ai-plugin.json - plugin-style discovery manifest.

{
  "tool": "intermittent_fasting_window",
  "protocol": "16:8",
  "first_meal_time": "12:00",
  "fast_days": [
    "Monday",
    "Thursday"
  ]
}

Open tool contract JSON Open AI integrations guide

Expand developer notes

Agent playbook

Resolve Intermittent Fasting Window Planner from /agent-tools.json and open its contract before execution.
Validate inputs against the contract schema instead of scraping labels from the page UI.
Open the browser page only when a person wants to review charts, assumptions, or related tools.

Agent FAQ

Should ChatGPT, Claude, or another agent click through the UI?

No. Start with /agent-tools.json, then follow the tool's contract URL. The page UI is for human review, not parameter discovery.

When do tools show Quick and Advanced?

Every tool opens in Quick Start first. Advanced Controls keeps the same scenario, reveals more assumptions or diagnostics, and every tool keeps AI integrations inline below the instructions.

When should an agent still open the browser page?

Open it when a human wants to sense-check the output, review the chart, or keep exploring related tools after the calculation finishes.

Questions people usually ask

Which fasting protocols are supported?

This planner supports 14:10, 16:8, 18:6, 20:4, OMAD (23:1), and 5:2 scheduling.

How are eating and fasting windows calculated?

Your first meal time sets the start of the eating window. The selected protocol determines eating and fasting durations across a 24-hour cycle.

How does the 5:2 option work here?

For 5:2, you pick two low-calorie fasting days each week. The planner highlights those days and shows a reference 24-hour fasting-day timeline.

Is this tool free and private to use?

Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.

Do these tools replace medical guidance?

No. These outputs are general fitness estimates — not medical advice.

Related Resources

Learn the decision before you act

Every link here is tied directly to Intermittent Fasting Window Planner. Use the explanation, formula, examples, and benchmarks to pressure-test the calculator output from first principles.

Browse all 10 resources

Guides · 2 Checklists · 1 Comparisons · 2 Tips · 1 Mistakes · 1

How To Use

5 STEPS

How to Use Intermittent Fasting Window Planner

Plan your ideal intermittent fasting schedule with our easy-to-use calculator. Find your perfect eating and fasting windows based on your lifestyle and goals. Optimize your IF journey.

Read

Guide

8 MIN READ

Intermittent Fasting for Beginners: How to Start

A practical beginner's guide to IF. Which protocol to start with, how to handle hunger, what the research actually shows, and who should avoid fasting entirely.

Read

Guide

6 MIN READ

How to Start Intermittent Fasting Safely

Begin intermittent fasting safely with expert guidance. Learn precise steps for choosing a protocol, calculating caloric needs, and making a gradual transition to avoid common pitfalls and optimize your health.

Read

Comparison

7 CRITERIA

16:8 vs OMAD: Which Intermittent Fasting Protocol Is Better?

Compare 16:8 and OMAD fasting for fat loss, muscle retention, adherence, and health. Evidence-based analysis of when each protocol makes sense.

Read

Comparison

6 CRITERIA

Intermittent Fasting vs Regular Meals

Uncover the benefits and drawbacks of Intermittent Fasting versus Regular Meals. Compare metabolic effects, hunger management, and social impact to find your ideal eating pattern.

Read

Examples

4 EXAMPLES

Intermittent Fasting Examples

Explore practical intermittent fasting examples for diverse lifestyles, from busy professionals to endurance athletes. Understand how flexible fasting protocols can enhance health and performance.

Read