Question about IF and Keto

(Meara McLaughlin) #1

Could be a stupid question, but…
When you do intermittent fasting do you reduce your calories by the same amount? So, for instance if you fast for 20 hours and only eat for 4 hours, do you need to only eat 1/2 of your normal caloric amount? Or do you need to pack the same amount of food as if you had not fasted.

(Alec) #2

There are no rules. However, I think it is generally accepted that continuous daily undereating and calorie restriction will reduce your metabolic rate.

So, in principle, you should eat as many calories as you would normally in a day to ensure you are not damaging your metabolism.

So, how does this help reduce weight? By only eating once per day, you are greatly reducing your overall insulin load. By having low insulin, you allow a long time with your body accessing bodyfat.

So, in fact there are different guidelines depending on how fat adapted you are. If you are well fat adapted, your body can easily access bodyfat for fuel, and therefore eating a full days calories in your one meal is not that important as your body will use stored fat instead, and importantly will not be chronically starved of fuel.

However, if you are not well fat adapted, your body may well be under fuelled for a period of time if you don’t eat to a normal calorie number.

OMAD can be challenging for this reason: how do you make sure you are eating appropriate calories? Eating to satiety is an important principle of keto. If you get too hungry during an OMAD day it’s a sign you are not fat adapted yet, and you need to make sure your single meal is a real big one!!

(Meara McLaughlin) #3

Thanks for that, Alec. I’m new at this WOE so I do not know what OMAD stands for. Translation?

(Meara McLaughlin) #4

Thanks for
that, Alec. I’m new at this WOE so I do not know what OMAD
stands for. Translation?

(Alec) #5

:grinning:. OMAD One Meal A Day. TMAD Two Meals A Day

If you are new to keto and fasting, then I would strongly recommend starting out doing keto for a few weeks and start the fat adaptation process.

Keep it simple to start. Keep carbs below 20g per day, eat to satiety, eat when hungry.

(mole person) #6

The principle is to eat as much as you need to be good and satisfied in the window. I’m OMAD most days but TMAD a couple of random days a week when I feel very hungry earlier in the day. My calories range from 900-1300 on my OMAD days and from 1400-2000 on my TMAD days. I’ve been doing this for two years and have not had any noticeable change in my metabolism. This strategy got me all the way to my goal weight.

(Carl Keller) #7

Let your hunger decide how much that is. If you are fat adapted your body fat will make up any caloric deficit. When I’m doing OMAD, I can eat about 1.5 normal meals worth of food before I reach satiety.

(Meara McLaughlin) #8

That’s easy. Thanks

(Todd Batitis) #9

How it affects your metabolism will differ depending on whether you are doing IF occasionally or all the time and for how long your fasting period is. If you are doing something like 16:8, you should have no problem getting all your macros (and calories) in during that big eating window. If you are doing OMAD one day, and only eat a smaller amount and then not doing IF the next day and eating fully, your metabolism isn’t going to take a big hit.

Now, if you are like me, who does 20:4 everyday (weekends I am starting to open to 18:6 now and then) it is different. My BMR is currently just under 2000 calories and I eat between 1800-2200 calories daily within the appropriate macros regardless of whether that ends up being 20:4, 22:2 or simply OMAD. If I were eating a lot less, say 1000 calories, simply because I am only eating in that small window my body will rebel against the constant deficit and start compensating by lowering my metabolism dramatically.