Is this diet too extreme?

Is your diet too extreme?  If you check out this master cleanse secrets review then you’ll see the diet involves you drinking just lemonade and maple syrup.  Now this particular detox/diet has been around for about 50 years, so you think if it was really dangerous then it would have been squashed a long time ago, but I can’t help thinking that it is not safe to just drink what is essentially sugar.  Surely that must have serious implications and might lead to diabetes because of constant messing around with your blood sugar levels like that?  I don’t know of any major concerns that have been raised but it isn’t something I would try myself!