I've just spent a month fasting every other weekday (Mon Wed Fri). I drank liquids including mixtures of fruit/vegetable juice with pulp sieved out. I've also put on weight during the month. I didn't increase my intake on food days. I didn't do it to lose weight but you'd expect there to be some reduction.?!??!!? My theory is that actually basal metabolic rate is a myth and that it's all variable and chaotic. I don't think anyone really understands how our metabolism works. You know what's a bitch? Running a 2000-calorie-a-day deficit and gaining weight.
Well, my basal metabolic rate was pretty heavily fucked up by spending my teenage years as an exercise bulimic. At my lowest I was 80lbs lighter than I am now. My theory is that my metabolism is in siege mode most of the time, but when things are actually stressful I go full Stalingrad. And I've been full Stalingrad for about 30 months now.