Use www.weightlossresources.co.uk to calorie count. I've lost 42kg over 18months and successfully maintained that weight for 6 months now because of the good lessons learned during the loss period. It's essentially eat less. They put you in deficit by 500cals per day so if you burn 800cals during exercise, you get to eat those calories in order to maintain the 500cal deficit. It makes a lot of sense to me, it might not to you but you can do a 24hr free trial and see if you like it.