There are risks of course, but Exante products are designed (and legal) to try to minimise those.
These are the ones I've seen on t'internets of "publicised" risks
Getting into ketosis - we all know about the brain fog/hunger/tirednes/sickness that can occur. It's unavoidable. However, whilst on ketosis your body won't experience and sugar downfalls (which I think is one of the primary reasons you don't get as hungry) so its just a few days of feeling a bit **** while your body uses all of the remaining carbs.
Fat levels - some people on a ketogenic diet are consuming a lot of fat which has been highlighted in the reports about it. Obviously none of the people on here are consuming a lot of fat, so its not applicable in this situation.
Lack of vitamins - again, non applicable, ALL of the required nutrients are included in Exante stuff.
Ketoacidosis - only applicable in diabetics whose insulin control is abnormal.
I think somehow it may be a positive for some obese people whose insulin is being overproduced, as it slows all of that away down and means that hopefully after these VLCDs, maintenance is more achievable
At the end of the day, the UK is VERY strict on food legalities. If this was not safe it would not be sold in the UK.