Isn't IF (or fasting in general) just calorie restriction?

(Karl L) #1

So I did 3 days of 18:6 this past week followed by a 25hr fast starting after breakfast Saturday. According to my scale, I lost about 3.5lbs. I also consumed far fewer calories this past week than on a normal keto week. So my n=1 could have two possible conclusions: 1) Fasting causes complicated biochemical reactions which lead to weight loss, and 2) Consuming fewer calories leads to weight loss.

(Adam Kirby) #2

Calorie reduction only works in the context of low insulin which permits fat burning to make up the energy deficit. It is easily possible to restrict your calories while keeping insulin high and have no fat loss (most failed dieting). That’s why fasting works so well, lowers insulin greatly. Another confounding issue is the fact that you can only pull a limited amount of energy out of a fat cell every day, meaning slender ppl can’t burn fat at the same rate as heavy people even with a similar calorie reduction.

(Karl L) #3

Thanks Adam. Yeah, I’ve been reading up on this and somewhat understand the science, just saying that with the available data from my N=1, I can’t really know the weight loss mechanism.

(Adam Kirby) #4

You have low insulin = easily mobilized fat stores.

Also keep in mind that some of your weight loss could simply be not having any food in your stomach or water weight loss. Notice if weight goes back up when you resume eating normally.

(Cathy) #5

I struggle with the question too. The ci/co theory is hard to dispel completely from my thinking despite the fact that I have more than 10 yrs. of keto under my belt.

I think keto diets help with weight loss because of the low insulin effect. This has nothing to do with energy balance.

I think fasting does the same thing for the same reasons. Again, nothing to do with energy balance.

I think low calorie diets work for the same reasons. Carbohydrates are always lower and food consumption in general is lower allowing for lower insulin. Again, not an energy balance thing.

In all cases, the body seems to adapt and weight loss will stop over time.

This is where fasting can be useful because it is changing the dynamics. If a person is to fast on the same schedule, weight loss will stop.

That leaves the elusive question of what is it that is changing in the body to prevent weight loss?

#6

Also it’s only a 1 week comparison. Do that same thing for 3 weeks, then see how you are doing.