Whoops. Have lost 7lb in 11 days. Need to dial up the calorie intake, cause that's not healthy.
How did you do that?
By eating less while still cycling 17 miles each day. By eating carefully, with plenty of fruit and vegetable intake and enough slow-release carb content to keep my energy levels up. All the boring stuff. It's just a matter of discipline, but it does help that I know I can do it, having done it before.
Back when I decided that I had to do something about having drifted slowly up to 15 stone, I switched to a very healthy diet, planned a careful exercise regime and lost four stone in eight months. It was a genuinely life-changing experience, which left me fitter than I had ever been in my life and with a new habit of setting and achieving goals. I stayed healthy, fit and active and I only drifted into being overweight again because I eventually decided to set goals based on something other than bodyweight (I moved on to strength training), partly to prove to myself and others that I hadn't strayed into anorexia.
I'll be increasing the calorie intake a notch to achieve a more sensible rate. In any case, in my experience you get the highest return from your efforts at the beginning, with diminishing returns as time goes on.