1. Healthy Eating

Nicholas Rush, RDN, CDN

January 26, 2021

Intermittent Fasting vs. Keto – Is there a superior diet?

Among the popular health trends out there, the keto diet and intermittent fasting (IF) are some of the hottest topics being talked about right now. These methods have been used to help lose weight and keep some health conditions in check, but is there a superior diet among these two? Let’s check out the benefits and drawbacks of these two health trends!

What is intermittent fasting?

Intermittent fasting is a diet pattern that revolves around fasting and periods of either unrestricted eating or eating significantly less calories. In other words, fasting means that you are voluntarily not eating or reducing your caloric intake significantly. The theory behind this diet is that it decreases appetite by slowing down the body’s metabolism.

Methods of Intermittent Fasting

There are three common methods for intermittent fasting.

  1. The first method is alternate-day fasting. This method consists of alternation between days of no food restriction, with days that contain one meal that provides about 25% of daily calorie needs.
  2. The second method is whole-day fasting, which consists of having 1-2 days of the week where you fast for the day or consume up to 25% of your daily calorie needs.
  3. The third method is time-restricted feeding, where you fast for a certain amount of time and designated eating window. For instance, you would fast for 16 hours and have unrestricted eating for 8 hours.



How does keto work?

The keto or ketogenic diet, is a low-carbohydrate, high fat diet. The diet is commonly used as a treatment for epilepsy in children. However, due to the popularity of low-carb diets, the keto diet has been gaining a lot of attention. The theory behind the ketogenic diet is that you deprive the body of glucose, the main source of energy. As a result, the body switches to an alternative fuel called ketones that is made from stored fat. As this continues for 3-4 days, stored glucose is depleted from the body. Therefore, the body begins to use fat as its main fuel. In addition, the body will enter ketosis, as ketones accumulate in the blood. Achieving true ketosis is a difficult task, as many foods (or even medications) contain carbohydrates. At the end of the day, the keto diet is just another low carb diet, but more extreme.



CONCLUSION: What does the science say?

We have established that both diets have their pros and cons. These two diets may be suitable for weight loss, but studies have shown that neither diet yields superior results in weight loss or any other health marker as compared to a healthy eating pattern rich in lean proteins and whole foods such as fruits, vegetables, legumes, and whole grains.

In conclusion, neither diet is superior to the other. More high-quality long-term studies are needed to show any substantial evidence of potential benefits. If you decide to try any of these diets, be sure to consult with your physician and dietitian first! Both diets have their pros and even potential harmful side effects. At the end of the day, both diets restrict calories and therefore result in weight loss. However, this can still be achieved without strict dieting and altering the way our bodies naturally use energy.

Before turning to a strict diet, consider a more balanced diet that includes all the food groups, like the Mediterranean diet, to achieve your health goals.

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