Tbh most of the vlcd's are out of the 5% rule. But there are some that are not.
As someone who has done both normal and vlcd diets, the only thing the tablets will do is stop you binging on fatty foods.
I started when I got the tablets on the slim fast range ( premade shakes) and the low fat (within tablet rules) and under 600 cals which is the slim fast plan. Worked a treat and that's what got me to the pictures in my sig if you can see them.
It worked for me that plan as I learnt about choosing healthy 100 cal snacks that were low fat and low cal, I didn't have to worry about what I was going to have for 2 of my meals ( untill I was ready and could get my head around it all)
To do just a vlcd like Cambridge for example, the tablets themselves won't do anything.
Hope this has helped, and its just one persons opinion, and experience...