Keto Diet vs. Intermittent Fasting: A Comprehensive Guide

In your quest to eat healthily or achieve your fitness goals, you’ve likely come across eating styles such as the ketogenic diet (“keto” diet) and intermittent fasting. Both have gained significant popularity due to their potential health benefits in recent years, particularly in supporting metabolic health. While they’re founded on different principles and methodologies, each offers its own unique advantages and disadvantages. 

Whether you’re considering adding intermittent fasting into your current keto eating plan or you’re curious about which methodology fits best into your lifestyle, we’ll provide a comprehensive comparison of the keto diet and intermittent fasting.

Understanding the Keto Diet

At its core, the keto diet is a low-carbohydrate, high-fat diet. Its central principle revolves around driving the body into a state of ketosis, a metabolic state where the body, due to the scarcity of glucose (its preferred energy source), begins to burn stored fat for energy. 

In order to reach ketosis, one must significantly reduce their carbohydrate intake. The types of high carbohydrate foods that must be significantly reduced or eliminated altogether on the keto diet include: 

• Sugar, honey, and most sweeteners
• Grains 
• Starchy vegetables 
• High-sugar fruits 
• Breads and baked goods

Low-carb foods you can (and should!) eat when you’re following a keto lifestyle include: 

• Meats
• Seafood
• Eggs
• Cheese
• Yogurt
• Butter or ghee
• Non-starchy vegetables (such as broccoli, peppers, and spinach)
• Nuts and seeds

Types of Keto Diets 

The keto diet comes in several variations, including:

• The standard ketogenic diet, which typically allows macros of ​​75% fat, 20% protein, and 5% carbohydrates per day 
• A cyclical ketogenic diet, which might involve one or two higher carb days while sticking to a strict ketogenic diet for the remainder of the week
• A targeted ketogenic diet, which allows you to increase your carb intake in accordance with your workouts
• A high-protein ketogenic diet, which increases the macro ratio to 35% protein, 60% fat, and 5% carbs 

These variations differ primarily in their distribution of macronutrients, with the standard ketogenic diet being the most common form practiced.

Benefits of the Keto Diet

While the research is still evolving, the ketogenic diet has been associated with numerous health benefits. Some of the studies surrounding the benefits of a keto lifestyle include topics like: 

• Weight loss or management 
• Controlling blood sugar levels
• Reducing the risk of heart diseases
• Reducing the risk of certain types of cancer
• Alleviating the symptoms of neurodegenerative diseases like Alzheimer’s and Parkinson’s
• Potential benefits for conditions like Polycystic Ovary Syndrome (PCOS) 
• Treating acne and other skin conditions 

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Understanding Intermittent Fasting

Intermittent fasting, unlike the keto diet, does not restrict what you eat, but instead focuses on when you eat. This dietary practice involves cycling between periods of eating and fasting. 

The fasting period can range anywhere from 16 hours each day (as in the “16/8 method”) to 24 hours twice a week or even longer, depending on the specific intermittent fasting method chosen.

During the fasting periods, the individual typically abstains from consuming anything other than water, black coffee, or unsweetened tea. The underlying objective is to prolong the body’s natural fasting state (which occurs when we sleep) to promote metabolic changes similar to those seen in a ketogenic diet.

Benefits of Intermittent Fasting

Intermittent fasting also provides several health benefits. Here are some of the health benefits of intermittent fasting that are currently being studied: 

• Promoting weight loss and maintenance
• Improving metabolic health
• Regulating blood sugar levels
• Reducing inflammation 
• Supporting hormone health
• Reducing the risk of cardiovascular disease 

Keto Diet vs. Intermittent Fasting: Key Differences

The main difference between the two diet plans lies in their fundamental principles. The keto diet is focused on what you eat (namely low carbs and high fats), aiming to put the body into a state of ketosis. 

Intermittent fasting, on the other hand, is concerned with when you eat, with the goal of extending the body’s natural fasting state.

While both eating styles can help to manage a healthy weight and offer several health benefits, they differ in their methodologies and potential side effects. The keto diet may be associated with potential health risks, such as a higher intake of saturated fats. Intermittent fasting, while generally considered safer, can be challenging to adhere to and might not be suitable for people with certain health conditions or those taking specific medications (learn more about intermittent fasting and keto). The success of either dietary plan will largely depend on an individual’s health condition, lifestyle, and personal preference.