“You tend to get more cranky and feel more angry at life when you’re on something on that long-term, you’re probably not getting enough calories and you’re not getting enough nutrients you need. 

“Also when you juice, it releases sugars more quickly and that can release little sugar-spikes.

“[In turn] you feel grumpy and it also removes a lot of the fibre which we need for our gut health and to stabilise our blood sugar

“So while it can cause sudden and short-term weight loss, the long term issues with it can be more significant,” the doctor added. 

Source: Daily Express | Diet