Keto and Intermittent Fasting: How They Work Together

Keto and intermittent fasting are often used together—and for good reason. They both help your body burn fat. They both reduce blood sugar. And when combined, the results can be even better.

This guide explains how they work, how to do both safely, and what to expect. Many people find that adding intermittent fasting to their keto routine helps break through plateaus and improves their energy levels.

What Is the Keto Diet?

Keto is a low-carb, high-fat diet. The goal is to get into ketosis, where your body runs on fat instead of carbs.

• Eat under 50 grams of carbs per day
• Fill up on fat and moderate protein
• Your body makes ketones, which it uses for fuel

Keto can help with weight loss, insulin resistance, and sustained energy ¹.

Related guides:

• What Is Keto?
• Keto Macros Guide

What Is Intermittent Fasting?

Intermittent fasting (IF) is an eating schedule, not a diet.

You eat only during certain hours and fast the rest of the time. The most common schedule is 16:8—you fast for 16 hours, eat during an 8-hour window.

Other options:

• 14:10 (easier for beginners)
• 18:6 or 20:4 (more advanced)
• OMAD: One Meal A Day (very strict)

When you fast, your insulin drops and your body starts burning fat for energy. That’s where it overlaps with keto ².

How Keto and Intermittent Fasting Work Together

Keto and IF both lower insulin and support fat burning. When combined:

• You enter ketosis faster
• You stay in ketosis longer
• You may lose fat more efficiently
• You feel less hungry (ketones reduce appetite)

Here’s the thing: keto makes fasting easier because fat keeps you full. And fasting makes keto more effective because you’re not eating around the clock.

Benefits of Doing Both

Sample Schedule: Keto + Intermittent Fasting

16:8 Eating Window Example

You’re still eating keto foods—just in a shorter window.

What to Eat During Your Eating Window

Stick to normal keto meals:

• Eggs, meat, fish
• Avocados, olives, nuts
• Leafy greens and low-carb veggies
• Cheese, butter, coconut oil

Related guides:

• 7-Day Keto Meal Plan
• Keto Recipes
• Best Keto Snacks

When Not to Combine Keto and Fasting

While most healthy people can do both, there are exceptions. Talk to a doctor first if you:

• Are pregnant or breastfeeding
• Have a history of disordered eating
• Take blood sugar medications
• Have adrenal or thyroid conditions
• Feel lightheaded or weak while fasting

Start slow. It’s okay to begin with just keto or just a gentle fasting window.

Real Example

Linda, 52, started keto to lose weight. After 3 weeks, the scale stalled. She added a 16:8 fasting schedule, eating from noon to 8 pm.

In the next month, she lost 7 more pounds and said she had “zero cravings and way more energy.”

Now she sticks with keto and fasts 5 days a week.

Tips to Make It Easier

Stay hydrated: Drink water, coffee, or tea during fasting hours.

Get your electrolytes: Add salt, magnesium, and potassium—especially in the first week.

Avoid snacking: Stay disciplined about your eating window.

Eat real food: Stick to whole foods, not “keto junk.”

Be consistent: It gets easier over time as your body adapts.

Frequently Asked Questions

Do I have to fast to do keto?
No. Keto works on its own. But fasting may speed up results.

Can I eat carbs during my eating window?
If you want to stay in ketosis, you still need to eat low-carb.

Will I lose muscle while fasting?
Not likely if you eat enough protein during meals and stay active ⁶.

Summary

• Keto and intermittent fasting both help your body burn fat.
• Combining them may improve weight loss, energy, and focus.
• Keto makes fasting easier by reducing hunger.
• Start slow, listen to your body, and don’t overdo it.
• Always check with your doctor if you have health concerns.

What to Read Next

• Keto Meal Plan for Beginners
• What Is Keto?
• Keto Macros Guide
• Keto Side Effects and How to Avoid Them