Hi there! I crash dieted. 1,500-1,900 calories per day, at a TDEE of 3,000+ (lift 6 times per week on a PPL, as well as working 30-40 hours per week as a stock boy stocking bulk foods) Results:
The extra photo is me 3 weeks later. Binged it all back and then some, and did not even gain most of my strength back in that time. Take a look at research done on contest prep bodybuilders, the most interesting fact is that almost all of them are unable to maintain low bodyfat and almost all of them actually overeat themselves back into a higher bodyfat than they started.
That is not everyone, obviously with willpower and intelligent, well thought out plan you can avoid these pitfalls but just be extremely, extremely prepared for the insane hormonal surge you are going to experience when you return to normal dieting.
*Insomnia *Dehydration *Loss of mental sanity *loss of focus and motivation *No sex drive whatsoever
These symptoms mentioned by another user cannot be overexaggerated, I have never felt so shitty in my life, was unable to carry even the most basic conversation and was regularly slurring my words and had some very awkward moments with customers because I often could not think straight and had to have them repeat basic questions a few times.