The FastDay Forum

Hi everyone - I was reading through some posts and stared to wonder if I should adjust my fast day calorie allowance?

I've been going with the basic 500cals/day on fast days, without calculating a TDEE. I am happy owner of a fitbit which monitors my movement throughout the day and have a pretty good idea how many calories I expend on a day to day basis.

My question is - should I be aiming for 25% of my typical calorie burn (BMR plus normal activity) , or should I be sticking with the 500?

Thanks in advance

Alli x

I'm not the expert, but I think Michael Mosley advised not to take exercise into account. If you're thinking about increasing your fast day intake above 500cals, I'd say don't do it if your goal is weight loss. Sticking to 500 and additional exercise/ movement should result in better (quicker, higher) weight loss.

You're better off sticking with 500 cals, but it's helpful to calculate your TDEE just in case that 25% of it iss less than 500

Yes, stick to 500. No more, no less.

I started from the book, hence going with the 500 and not adjusting for exercise. But then seeing all the comments about TDEE I started to wonder. Most fast days I end up with a deficit of about 2500, but I guess that's not a bad thing...?

I don't trust my fitbit to be that accurate. I am sticking to the 500.