Intermittent fasting and the ketogenic (keto) diet are two powerful dietary strategies for weight management and improved overall health. While their approaches are different, their end goal is similar: to support normal, healthy blood sugar levels and to use more fat for energy, rather than glucose.
With more than one way to achieve the results you’re looking for, choosing an approach depends on your goals, personal preferences, and lifestyle habits. Let’s break down the intermittent fasting vs. keto debate in more detail.
Intermittent fasting: When you eat
Intermittent fasting is a time-based approach to eating. It involves a regular cycle of fasting (usually 12–16 hours) and eating (8–12 hours) each day.
Fasting allows the body to use up the body’s stores of glucose for energy so it can burn fat for energy instead. This process is called ketosis.
Scheduling our eating in this way can bring a variety of benefits, including:
- Improved digestion
- More energy
- Improved sleep quality
- Weight-management support
- Lower blood sugar levels
- Improved insulin sensitivity
- Heart health support
The greatest benefits are shown to come from the 16:8 intermittent fasting schedule. For example, this could mean finishing eating at 6 p.m. and fasting until 10 a.m. the next day.
One of the biggest draws of intermittent fasting is that there are no restrictions on what you eat, which means you don’t have to sacrifice your favorite indulgences! However, intermittent fasting works best when you eat a nutritious diet with a variety of healthy foods.
Keto: What you eat
Keto focuses on what you eat, not when. It is a high-fat, low-carb diet that shifts your body into ketosis. Similar to intermittent fasting, a keto diet allows the body to burn fat for fuel instead of glucose (carbs).
Some of the benefits of keto include:
- Improved appetite control
- Weight loss
- More stable blood sugar levels
- Enhanced mental clarity
To stick to this diet, people follow three main guidelines:
- Limit carbohydrates—fewer than 50 grams per day
- Increase healthy fats—these should make up the majority of your daily calories
- Moderate protein—protein should take up about 20–25% of your daily caloric intake
While intermittent fasting allows for plenty of flexibility regarding what you eat, keto is much more restrictive, focusing heavily on healthy fats and protein like fatty fish, dairy, and non-starchy vegetables.
Which is better: Intermittent fasting or keto?
Intermittent fasting and keto are two peas in a pod. Each affects how fats and ketones are used in the body, which in turn affects our overall health.
So, the “right” method depends on what works best for you. If the thought of tracking what you eat is unappealing, you might find more success with intermittent fasting. If you don’t like the idea of only eating during a certain window each day, keto might be the better alternative.
If you’re still unsure, consult with your healthcare provider to help build out a diet plan that works best with your goals and lifestyle.
Combining intermittent fasting and keto
Of course, you don’t have to choose between one or the other. In fact, combining intermittent fasting with a keto diet can help amplify the positive effects you’re going for, whether it be weight loss, better glucose levels, or more energy. And since foods you eat on a keto diet tend to be more energy dense and filling, this makes it easier to go longer periods without food.
In short, the two methods are natural partners in helping you reach your health goals. If you’re thinking about doing both, take note of the following tips before getting started.
Keto first, intermittent fasting second.
If you’re new to both, starting with keto can be a good way to smooth the transition to intermittent fasting. A low-carb diet like keto helps to diminish hunger and cravings, which makes it easier to fast during your fasting window.
Be consistent with your fasting schedule.
The key to making intermittent fasting work is finding the right fasting window for your lifestyle—and sticking with it. The 16:8 schedule (fast for 16 hours, eat all your meals during the remaining 8 hours) yields the best benefits of intermittent fasting. For some that means skipping breakfast, while others prefer an earlier dinner with no snacks afterward. If you’re new to intermittent fasting or the thought of fasting for 16 hours is overwhelming, people often have more success with consistency if they begin at 12 hours and slowly increase to 16 hours of fasting.
Drink lots of water.
Adequate hydration is important for both intermittent fasting and keto, as both can cause your electrolytes to fluctuate. So keep a water bottle nearby, or drink Unimate if you need a sugar-free pick-me-up.
Eat real food.
Ultra-processed foods, even if they are keto friendly, usually aren’t satiating, and often lack essential nutrients. Opt for whole foods—leafy greens, nuts, eggs, Greek yogurt, fatty fish—as much as you can to make sure you’re hitting a variety of nutritional groups each day and are filling up on foods that will keep you satiated.
Any time you start a new diet plan, it’s a good idea to track what you eat (and when). Pay close attention to healthy fats, proteins, and carbohydrates and make sure you’re getting the right balance of each for keto. Tracking your eating habits for a few weeks can shed light on which food areas you need to improve on and what habits need to change to get you where to want to be.
Listen to your body.
Everyone responds to intermittent fasting and keto differently, so make sure you take it slow at first and pay attention to how your body feels as it adjusts. If either practice is too difficult to maintain for longer than a few weeks, then you might need to reconsider your approach (i.e., shorten your fasting window, bring different foods into your diet). As always, consult with your doctor first before making major changes to your diet.
A combined approach for optimal results
Combining intermittent fasting and keto can be a powerful way to help you achieve your health goals—it doesn’t have to be one or the other. Just be sure to exercise care and patience to make sure you’re striking the right balance for your needs and lifestyle, and prioritize whole, nutritious foods over processed foods to get the best results.