So, here's an interesting concept that I came across yesterday, something my brother is going to give a shot at. For people that are just starting out or have one or more things they want to change, it's a gentle strategy that may work for them.
Some people are okay with the immediate change of all dietary and exercise plans but for those that want a different approach, give the above a try, or do a mix of the two variations.
1 change a month, examples:
Remove one item from your diet
Give up something which is draining some of your free-time
Start a new exercise plan
Stop one bad habit
Start one good habit
Add something new into your exercise plan (cycling to work etc)
Choose one item each month, from your own goal list, but try and keep it going all year; this means in one year you should have made 12 changes which will help you get to your goal.