This is tough for me, because I’m a big do you believe what the studies say or your own lying eyes kinda guy. About a year and a half ago I tried going on a rather intense caloric reduction protocol. I was eating about 1,000-1,400 calories a day as a 6’2”, 170 lb male. Over the next 5 months I gradually fell to a low of 138 lbs, I had literally no energy, was waking up in panic attacks in the middle of the night at least twice a week, and was in a terrible mental state. I should mention, for about 2.5 months I completely cut out all dairy, meat, and eggs, maybe this is where I went wrong. Either way, like many have taught throughout history, I have learned that their are equilibriums you must find for yourself, you know when you are straying too far outside equilibrium because you feel it. Error on the side of eating less, for sure, but I have found a balanced day with lots of movement trumps everything else for me personally.