Brassica If your TDEE is 1550, then you are very short or have little to lose. Technically fasts should be 1/4 of TDEE BUT For many overweight people, learning to live within their TDEE is such a shock to the system, that 500 is the best number to work with (that and all the recipes are based around 500!)
Thanks Talkin - yes, I'm fairly short (160cm) and ticked the box for sedentary because I have an office job and never get to the gym. I'd like to lose a stone - my BMI is fractionally under 25 and I carry all my chub round my middle so it seems a good idea to try and lose some of that fat if I can.
You'll lose ok with 500 cal FDs. Even for small women, it still gives a big calorie deficit. Women with high TDEE can optionally go to the 25% TDEE - mine is 2400 and I exercise intensively, so I do 600 FDs.