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I’m sure you, like many people, have heard about the intermittent fasting (IF) and keto diet. There is so much information online, and a family member or friend might have shared their experiences with you. But I have found that for many people, knowing what these eating plans are exactly, and more importantly why they work in tandem, is not something they can put their finger on. 

Starting with some basic definitions, and some clear principles, I believe anyone can see why these two ways of eating work together and get amazing results. 

We’ll start at the very beginning with those definitions. 

Intermittent fasting (IF) involves having a shorter daily window when you eat, the most common being 16:8, where you eat during an 8-hour period and do not eat for 16 hours (or drink beverages with calories or artificial sweeteners). Remember your 16-hour fast involves a night’s sleep so the shift in eating pattern is not always too dramatic, starting at 11am for example, and finishing by 7pm. Meal schedules can include 3 meals, 2 meals, or the 1. Starting with 3 meals often makes the change easier, as it’s closer to how you might have eaten before. It’s important not to snack between these meals.

Keto comes from the word ketosis, a state your body functions in when you eat with very low carbohydrate (and therefore sugar) intake. Ketosis is when the body uses ketones as an energy source rather than sugar. Ketones are fat molecules, and there is a basic fact to keep in mind: there are two types of fuel that the body uses for energy – ketones/fats and sugar. 

I like to use an everyday example to compare how the body burns these 2 types of fuel.

Take a pan of bacon (fat) and a pan of sugar and turn the heat up.  Which one do you think burns faster…the sugar or the bacon? The sugar burns faster than the bacon. Therefore, when you consume sugar, it burns up in your body just like it does in the pan…FAST!  So if your body is running off of sugar as its fuel source, your body will require for you to consume more and more of it to function which means snacking, snacking and more snacking throughout the day. 

Which brings me to insulin, its relationship to sugar, and the vital role it plays in weight and fat loss. Insulin is a hormone, and a hormone is a messenger the body uses to tell it to do a number of things. With insulin there are 3 adverse effects it has on weight loss. When insulin is present in the body it:

• Converts extra sugar into fat

• Prevents fat burning

• Stops the healing and repairing of cells

Sugar triggers insulin production, and insulin prevents fat loss and cell repair. That is the simple guiding principle. 

So, the key is to 1) avoid sugars and focus on fat as your fuel, and 2) give your body the time to heal and burn fat during your fasting period with IF.

To avoid sugars cut out whole grains, low fat protein,excessive protein (which the body breaks down to sugar and then stores as fat), combinations of carbs and protein (like hamburgers), combinations of carbs and fats, MSG, high-fructose corn syrup and artificial sweeteners (that trigger insulin release but do not signal to our brain that hunger is satisfied).

The clear message to take away with you here concerns insulin. When insulin is not activated fat burning happens.

I know my clients have seen some dramatic transformations by adopting a Keto diet alongside IF. Once they see those results – and can clearly understand why these ways of eating work – there is no turning back for them. 

I am a Certified Dr. Eric Berg Keto/IF Coach.  Please do not hesitate to contact me at for a complimentary consultation.


Carlos FEnwick

I am a dynamic, energetic and compassionate personal trainer who delivers high quality training sessions to all of my Washington DC personal training clients. I am constantly in communication with my clients and persistent in getting them to their goals. My interest is seeing my clients do well not only in-home personal training but in all aspects of their life. I thrive on people around me flourishing and prospering.

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