Hi there

I think as long as you hv enough fat and protein in your meal and keep your carb intake as minimum as possible by not eating rice, instant noddle, wheat ...and another sweet suff that used to eat...etc. and only take the carb frm salad ang fruits... than you should okay, but make sure you drink a lot water. you may keep loosing weigh in this type of diet.
I drink a lot of mineral water, i know that some time you fill full when you drink two or three glass of water at one time so I avoid to sit alot after drinking water I just walk around the house to get the water down.
I hv no problem on my drinking pattern . To break the fast I drink mineral water one big glass and than I pray after that i start eating my dinner slowly as usual ( low carb intake) during and after eating I drink at least another 2 to three glasses . than go to the mosque nearby my house and pray again after that come home see tv show and before go to bed I drink another glass.
During Ramadhan in Indonesia we start fasting from 04:15 AM to 18:10 so we hv longer fasting period compare to you who stay in UK.

I still continue loosing my weigh in fact i loose my weigh faster during ramadhan.