Food 101: Intermittent Fasting

Disclaimer: I am not a nutritionist so everything I talk about is opinion based on studies I have read and various nutrition certifications I have earned.

As a personal trainer, I can’t not talk about food. Yeah. That's a double negative.

Food is quite simply the most important part of your life. It can make you or break you, give you strength or make you sick and tired.

It never fails. I always get questions about the most recent craze, asking my opinion on its efficacy, with the hopes that there is some magic pill… like, “If I could just follow this one simple rule, everything thing else will fall into place.”

I get it. I’ve been there. Low fat. Low Carb. Vegan. Paleo, Keto, Fasting, etc. What’s the best? The most effective?

The answer, like so many of my answers to other questions, is: It depends.

Today I want to talk about intermittent fasting, specifically talking you through a misconception about IF that I once had.

People ask me: Is IF a good way to lose weight?

Not necessarily.

It makes sense that fewer meals in a day might lead to fewer calories consumed.

But that’s NOT the point of IF.

The point of IF is to be periodically achieving a state of ketosis, meaning using fat for fuel, by eating only during a certain window of time, anywhere from 8 to 2 hours. Two hours of eating, basically means you’re getting one meal a day and fasting for the other 22.

20 Years ago, I would have argued this was the worst idea ever. Extended periods of calorie deficit have negative effects on your metabolism, namely slowing it down to a crawl so even your basal metabolic rate is slower than it should be according to your body stats.

But, it is possible to eat what you burn on an IF schedule. For example, 4 meals of 500 calories every 2 hours is a 6-hour eating window. Most of us have close to a 12-hour eating window or bigger. (who eats breakfast at 6 am and dinner at 8 pm?)

Just because you’re eating 1 meal a day doesn’t mean you’re in a calorie deficit. Of course, that depends on what you eat, but you can focus on calorie dense foods like healthy fats and protein to avoid getting filled up with water.

Here is where IF looks like it’s a great “diet” for losing weight: The advantages of achieving ketosis on a daily basis is that your body becomes very efficient with burning fat as a preferred fuel source AND you become more glucose sensitive. For those of us with excess fat to burn, your body has plenty to munch on between feeding periods so you are naturally less hungry. This causes you to eat less at feedings than you would if your body was inefficient with fat burning and glucose resistant/insensitive (diabetic or not, many of us with weight problems have some glucose resistance), thus you create a calorie deficit.

It’s not the IF that makes you lose weight.

The IF gets your body to use the fuel your body already has so caloric deficit happens on its own.

Caloric Deficit causes the weight loss.

If you have a tendency to get hangry, or lightheaded, or just generally do not deal well with being hungry, this might be a neat thing to try. Usually “hangry” is an indication that your body isn’t efficient with burning fat. Even if you have plenty on your person or more than you would like, your body doesn’t use it and you get symptoms of low sugar because it’s burned through the carbs and wants more. Sound familiar?

Is IF effective? Hell yeah. Will it work for you? Probably. Just ask yourself if this method can fit in with your lifestyle.

To reiterate: calorie deficit is what causes “weight loss.” The type of eating method or menu you consume can help determine if that weight is mostly fat or mostly muscle. IF is a great way to teach your body to burn fat.