The FastDay Forum

At the beginning of the week I calculated my TDEE and it said that on feast days I should be getting about 1500 cal and about 400 cal on fast days.

I know that I am supposed to stick to that, so no more than 400 cal on fast days, but what happened if I get less calories? Tomorrow is my fasting day and I have already a veg soup and some chicken ready (I am planning to do only one meal) and that comes to about 300 cal. Would that be any problem?

Since I started the 52 diet I have found myself controlling calories and what I eat more often, even on feast days, and that means that I could easily get less calories even on feast days

oh god! I am confused, they could be silly questions... maybe I am overly worried with no reason?

I reckon you are right.

It is your choice though, and no one would say go for it without at least knowing what your current BMI is, ant health issues, history of eating disorders, whether you will intend running with scissors at any pint.

Even then, it's a mute point, and I dare say a few of the ladies might be inclined to poke your eyes out for boasting how easy it is for you to eat under!!!!

(Not Carol though, she's lovely!)

Oh no... I didn't want it to sound easy, tomorrow will be my second fast so not sure how it will go... I think I am a little bit of a controller and if someone says 500 cal it has to be 500 for me or I'll get mad I'll see how it goes tomorrow, I am still experimenting the best way to approach my fast days...

I think that is the secret Vee, see how it goes, the joy of this WOE is just that you can do what you like really! Hopefully at the end of the week you will have eaten less that 7xTDEE, and for every 3500 cals less you have eaten you should loose a 1lb!

In general fasting with zero calories is the basis of all this stuff, the use of a 500 - 600 calorie "allowance" on "fast" days is just to make it easier / more saleable / harder to criticise.

The science on which it is based is largely alternate day fasting with zero calories on fast days, so doing 300 or so on a 5:2 protocol will be fine.

I go under my 500 calories probably about a third of my fasts. I leave all my calories for dinner normally, and if I'm not ravenous, I hit about 300 calories. This is becoming more common the longer I fast. But I also don't specifically aim for it - I know I can go up to 500 and happily do if I'm that hungry. I want fast days to be as pain free as possible, so they aren't something I dread, but rather something I enjoy as part of my regular eating pattern.

I agree with PhilT. The 500/600 numbers are a bit arbitrary based on 25% of average TDEE of women/men. It would be interesting to see a proper scientific study varying things like number of calories on "fast" days and number of "fast" days.

Perhaps more importantly, the arbitrary numbers seem to work, and seem to be sustainable.

Hi Vee,
I always eat less than 500 cals on my fast days..like yourself, I like to know I'm doing things right..... but I do not calculate on normal days.
I figured that if people can do 24 hour fasts and 4 day fasts with no food at all, then it's not going to harm me to go lower than 500 cals for 3 days a week.
If I was hungry or unsatisfied then I would eat up to 500 or maybe even 600 cals but I've always been satisfied, to date. I think if I ate the full 500 or 600 cals on a fast day then I might be a bit paranoid on a normal day so I do extra discipline 3 days a week (I'm doing 4:3), a bit of caution on 2 days and a "whatever" approach at the weekends - although funnily enough because I know I can eat whatever I like; I often am not tempted....but sometimes I just go with the temptation and do eat a little of whatever I fancy........really not sure if this is what I am supposed to do but I am free from guilt and my health and weight seem to be responding well.

I found weight loss very slow on 300 cals 5:2 - although I only have a small amount to lose in reality. I have tweaked what I do over the past 3 months or so and now do 2 x 36 hour total fasts, exercising on fasting days too. I am pretty certain that I could not have done that right from the outset but you really do adjust (almost in spite of yourself!) as you go along. Good luck.

I actually find it easier to eat nothing at all on fast days because once I've had something, my appetite really gets going. Then by the evening the hunger only comes in short waves so I can live without dinner.

The last few weeks I have been mixing it up a bit though and have done one day on 600 calories and the other day on zero. Week 10, but still feel like I'm experimenting and finding the right thing for me.