This may be going against the flow but personally I listen to my body and if I am hungry, I eat! But I do make sure that what I eat is healthy, nutritious and low in carbs if possible. I don't calorie count and never have but the weight is coming off fine so I must be doing something right.
With three gym sessions and swimming too each week I think 700 calories is too low anyway, you need food to give you extra energy and the last thing you want is for your body to go into starvation mode!
I would say worry less, you are doing brilliantly.
Cuppa xx