The other thing to keep in mind regarding the exercise, is that over time you will find yourself needing to do more to get the same benefit. I think your walks at the moment are great, especially if you live in a hilly type of area (like me
) but as your body gets fitter you will of course not get the same effect. Even just longer walks, adding in some runs, perhaps weights while your walking/running (my mum has some that she adds to her ankles and hands) might do the trick. Otherwise if you are so inclined there are other options, like the gym, team sports, etc.
Ideally I think people should like at consistantly losing 2kgs per month, HOWEVER this of course won't get you to your goal by October - and that said, 30kgs in 6-7 months is not what I would term unhealthy, particularily for someone at your current weight.
Also, I'm sure your body builder friend has a much better understanding of calorie intake and so on than I would, so not to disregard what he says, but do keep in mind that the daily needs of an athlete are very different from a regular person, especially in regards to carbs. My understanding is that athletes eat A LOT of carbs, simply because they burn so many and of course their bodies just eat up the glucose - regular people like us have to get by on a lot less
That said, despite my post earlier I dont neccisarily think carbs are BAD - and I still eat plenty - but sugar I've cut out a lot as well as extra servings of bread (sometimes still indulge @ brekky) I think this is ok - certainly its agreeing very well with my body at any rate