The ketogenic (keto) diet and Intermittent fasting (IF) are two popular strategies for burning fat and improving health. Simply put, the keto diet is a shift in our body’s fuel source from using carbohydrates to burning fat. IF is not a diet but a change in meal pattern and frequency of eating which also pumps up our ability to burn fat by tapping into ketosis.
IF + keto complement each other like bacon and eggs, and the combination can be magical as one’s body has already become accustomed to using its stored fat as fuel. When fat-adapted, going long periods between meals is a cinch and often feels natural. IF without keto is just misery (in my opinion), since you’re fighting through hunger, headaches, and tiredness until the keto tap is turned on.
So, what is IF?
IF simply means going a certain period of time without eating (fasting state), which typically lasts between 12-48 hours for most people. A common strategy is the 16/8 method, which means not eating for 16 hours and consuming meals within an eight-hour window. If this seems daunting, know that the time you sleep is counted as part of the fast. For example, with the 16/8 method, one may stop eating at 6 pm and then not eat again until 10 am the following day. Don’t forget that the time you’re sleeping is included in that fasting window!
One to two meals would then be consumed during the eight-hour window from 10am-6pm that day. Over time, people may begin extending the fasting period to 18/6, 19/5, and may even go a couple days without eating, relying on stored body fat as fuel. Many people also participate in shorter, but more frequent IFs, such as two to three times per week, while others may like doing longer periods of IF one to two times per month. The goal is to find what works best for you and your body, which may not include IF at all.
Example schedules to get you started:
If you snack between meals, first try just eating three meals per day without snacking, then try the following:
- Eat from 8am-8pm, fast for 12 hours.
- Eat from 8am-6pm, fast for 14 hours.
- Eat from 11am-7 pm, fast for 16 hours (also known as the 16/8 method).
Do you have to do IF with keto?
Heck no! IF is a strategy that has been shown to help people break through weight plateaus, balance blood sugar levels, increase nutrient absorption, and IF provides a natural way to detoxify and clean our body’s cells. However, if you are rockin’ ketosis and already feel awesome, then feel free to leave it out.
Keto veterans may have already discovered they are doing IF and didn’t even know it. Most often, people on keto naturally find they are going long periods between meals due to the satiating (feeling of fullness) effect of constantly being fueled by fat.
IF tips for success:
- Start slowly.
- Avoid IF during times of high stress.
- If you just started keto, consider waiting a couple weeks to try IF, which will allow your body to adjust and tap into stored body fat for fuel when you’re not eating.
- Listen to your body. If fasting doesn’t feel good and you’re forcing yourself to fast, STOP! This is your body telling you it’s time to end your fast.
- Stay hydrated using zero-calorie beverages like water, unsweetened coffee, teas, and electrolyte-enhanced drinks.
- When it’s time to end your fast, don’t binge or stuff yourself at the meals — just eat until you are naturally full. The goal isn’t to make up all the calories you didn’t eat while fasting.
Avoid IF or speak with your doctor before starting if you are:
- Under chronic stress
- Have a history of disordered eating, such as anorexia or bulimia
- Have a chronic illness that may be negatively affected by IF
Top health benefits that may be achieved through IF:
- May increase insulin sensitivity and stabilize blood sugar levels
- Can help break through weight loss plateaus by accelerating ketosis and fat-burning
- Increased mental clarity and cognition
- Cleans up and detoxifies our body’s cells
- May help prevent and treat cancer cells
- Can have an anti-aging effect
- Reduced inflammation and oxidative stress
Bottom line: IF and keto are both strategies for improving health and losing weight. When combined, symptoms of IF such as hunger, headaches, and tiredness are minimized. IF + Keto go together like bacon and eggs!
Tara Finnerty RDN, CSP, CD—is a ketogenic specialist and fat-fueled enthusiast. Tara is a registered dietitian in Utah and owner of Sugar House Nutrition LLC. Her aim is to provide nutrition support for people wanting to reap the many health benefits of the ketogenic (keto) diet. Her expertise in the keto diet was initially working with children who have uncontrolled epilepsy. Tara supports nutrition diversity and works toward helping people find an individualized approach to make healthy eating sustainable.