Its not advisable to follow someone else's plan, so rather wait until you can afford it, the reasons for this are as follows:
the plan is based on 3 hormones essentially, HGH insulin and seratonin, the
diet manipulates these hormones to flatten out your insulin levels and push up your hgh and seratonin levels. With elevated HGH and seratonin levels, your
body starts to lose
fat as it is in a state where it no longer needs to defend your
fat stores, this
fat loss does not come at the expense of muscle loss, this is key to the
diet. If you decide to follow someone elses
diet you probably will not achieve the hormone balances that are recquired for cohens to work properly and as a result the calorie deficit will be made up by your
body by the loss of muscle tissue. you will get lighter on the scale but end up fatter by percentage, which is what you definitely don't want, and you will balloon once you start eating normally again.
the fact that you are twins may mean that you have very similar diets in the end, but dont take that chance. if you want more info shout and i will post a more detailed response