What to Eat During Intermittent Fast

Various diets can be combined with intermittent fasting to optimize health benefits and achieve specific goals. Two popular options are the paleo and keto diets.

The paleo diet is based on the premise of consuming foods that our ancestors would have eaten during the Paleolithic era, emphasizing whole, unprocessed foods like lean meats, fish, fruits, vegetables, nuts, and seeds. The paleo diet is rich in nutrients and can help reduce inflammation, improve insulin sensitivity, and promote weight loss when combined with intermittent fasting.

The ketogenic (keto) diet focuses on high-fat, low-carbohydrate intake, which encourages the body to enter a state of ketosis. In ketosis, the body shifts from utilizing glucose to using ketone bodies derived from fat as its primary energy source. Combining the keto diet with intermittent fasting can accelerate the process of ketosis, enhance fat burning, and potentially improve cognitive function.

If you’re interested in learning more about paleo or keto, check out our courses on each topic. These books provide detailed information on the diets, their benefits, and how to implement them to optimize your health. I will also add a recipe guide for each diet within the course. The course also includes a 30-day challenge for each diet.

Food Groups and Key Nutrients

Regardless of the diet you choose to follow during intermittent fasting, there are some key components of a nutrient-dense diet to keep in mind. These are just general guidelines to follow if your not following a specific diet.


Proteins are essential macronutrients that serve as the building blocks for tissues, muscles, skin, and hormones. They are crucial for repair and maintenance of body tissues and play a key role in creating enzymes and antibodies for our immune system. Importantly, proteins also help to regulate appetite and promote satiety, making you feel fuller for longer, which can be especially beneficial during your fasting period.

To ensure adequate protein intake, include a variety of protein-rich foods in your eating window. These might include lean meats, fish, eggs, dairy products like yogurt and cheese, and plant-based proteins such as beans, lentils, quinoa, tofu, and tempeh.


Carbohydrates are the body’s main source of energy. They are broken down into glucose, which is used by our brain, muscles, and body systems for immediate energy needs, and the excess is stored for later use. Not all carbohydrates are created equal. It’s crucial to distinguish between simple and complex carbohydrates.

Simple carbohydrates, such as sugars, provide quick energy but can lead to energy crashes. They are often found in foods with little nutritional value, like pastries, sweets, and sugary drinks. On the other hand, complex carbohydrates, found in foods like whole grains, fruits, and vegetables, provide sustained energy and are packed with other nutrients and fiber.

When practicing intermittent fasting, focus on getting your carbs from these complex sources. This not only provides energy but also ensures a steady release of glucose, which can help maintain energy levels during your fasting period.


Fats hold significant importance in our diet, as they serve as a concentrated energy source, regardless of whether one follows the Standard American Diet or another eating plan. They are essential for maintaining cell membrane integrity, assisting in hormone production, and enabling the absorption of fat-soluble vitamins such as A, D, E, and K. Consuming healthy fats is associated with numerous health benefits, including enhanced cardiovascular health, reduced inflammation, and improved cognitive function.

Saturated, monounsaturated, and polyunsaturated fats are the three main types of fats, each with distinct chemical structures and properties. By understanding the importance of fats and their diverse roles in the body, we can make informed dietary choices that promote overall health and well-being.

Saturated fats

Saturated fats are typically solid at room temperature and are found in animal products like butter, lard, and fatty meats, as well as tropical oils such as coconut oil and palm oil. Although once thought to be a major contributor to heart disease, recent research suggests that moderate consumption of saturated fats may not be as harmful as previously believed, especially when part of a low-carb diet like the ketogenic diet.

Monounsaturated fats

Monounsaturated fats are usually liquid at room temperature and can be found in plant-based oils like olive oil, avocado oil, and canola oil, as well as in nuts and seeds. Monounsaturated fats are considered heart-healthy, as they can help reduce LDL (bad) cholesterol levels and increase HDL (good) cholesterol levels. Though this is only true in moderation, so don’t consume these in excess.

Polyunsaturated fats

Polyunsaturated fats are also liquid at room temperature and are found in foods like fatty fish, walnuts, flaxseeds, and plant-based oils. Polyunsaturated fats include essential fatty acids like omega-3 and omega-6, which play crucial roles in inflammation regulation and overall health. However, it’s essential to maintain a balanced ratio of omega-6 to omega-3 fats, as excessive omega-6 intake can promote inflammation.

While practicing intermittent fasting, aim to incorporate these healthy fats into your meals. They can help maintain your energy during fasting periods and provide numerous other health benefits.

  • Fatty Fish: Fish, especially fatty fish like salmon, mackerel, sardines, and trout, are high in omega-3s and have a favorable omega-6 to omega-3 ratio.
  • Chia Seeds: Chia seeds are an excellent plant-based source of omega-3 fatty acids and have a good balance of omega-6 and omega-3.
  • Flaxseeds and Flaxseed Oil: These are rich in ALA, a type of omega-3 fatty acid, and have a very favorable omega-6 to omega-3 ratio.
  • Hemp Seeds: These seeds are one of the few plant foods that contain a good balance of omega-6 and omega-3.
  • Walnuts: Walnuts are a good source of omega-3 fatty acids and have a favorable omega-6 to omega-3 ratio.
  • Grass-fed Meat: Meat from grass-fed animals tends to have a more favorable omega-6 to omega-3 ratio than meat from grain-fed animals.
  • Pasture-Raised Eggs: Like grass-fed meat, eggs from hens that are pasture-raised or fed omega-3 enriched feeds have a more balanced omega-6 to omega-3 ratio.

Whole Foods

Whole foods are foods that are consumed in their natural, unprocessed state. They are free of added sugars, preservatives, and artificial substances. This category includes fruits, vegetables, whole grains, nuts, seeds, lean meats, and fish. Whole foods are packed with essential vitamins, minerals, and fiber, making them incredibly nutritious and a vital part of any diet, including an intermittent fasting lifestyle. Incorporating a variety of whole foods in your diet ensures you’re obtaining a broad spectrum of nutrients.

Examples of whole foods to incorporate include sweet potatoes, quinoa, brown rice, barley, fresh fruits and vegetables, lean proteins such as chicken, fish, and legumes, and healthy fats like avocados and almonds.

High Fiber Foods

High fiber foods are particularly beneficial during intermittent fasting. Fiber adds bulk to your diet and helps you feel full, which can make the fasting periods easier to manage. Furthermore, fiber supports a healthy digestive system, aids in the prevention of constipation, and helps manage blood sugar levels.

There are two types of fiber, soluble and insoluble, and it’s important to include both in your diet. Soluble fiber, found in foods like oats, beans, and apples, dissolves in water and can help decrease levels of LDL cholesterol and regulate blood sugar. Insoluble fiber, found in foods like whole grains and vegetables, adds bulk to stool and promotes regular bowel movements.

Some fiber-rich foods you can include in your eating window are fruits and vegetables, especially with the skin on; legumes like beans, lentils, and chickpeas; whole grains like oats and brown rice; nuts and seeds; and tubers like potatoes and sweet potatoes.

Antioxidant-Rich Foods

Antioxidants are compounds that protect your cells from damage by counteracting harmful molecules known as free radicals. Consuming a diet rich in antioxidants can help reduce the risk of chronic diseases such as heart disease, cancer, and neurodegenerative diseases.

Many whole foods are naturally rich in antioxidants, making them excellent choices for your eating window. Brightly colored fruits and vegetables tend to be high in antioxidants. These include berries, citrus fruits, leafy green vegetables, and deeply colored veggies like beets and bell peppers. Other antioxidant-rich foods include dark chocolate, green tea, and spices like turmeric and cinnamon.