Why do I feel like this is a pop quiz? Whew, good thing I studied. Um, no, calories in, calories out is ridiculous at best, and a really mean and dangerous way to torture overweight people dealing with inflammation and thyroid conditions at it's worst.
I might consider it if people didn't poop, but we have these lovely digestive tracts that remove anything we don't require for energy from our bodies. So, if you to wayyyy overshoot your food intake, you'll poop more, but that is about it, your body will take what it needs and excrete the rest.
If I only ingest a small amount of food, but that food is inflammatory to my body it'll bloat right up. I can prove that if I readopt my old starvation diet of living on 2 scones and 4 8oz. nonfat lattes per day. It really helps pack it on if you avoid sunlight at all costs and have an undiagnosed thyroid condition too. I managed to gain 30 lbs. I didn't want in 2 months.
I may be an oddball, but I have starved myself fat, and feasted myself thin several times. So the math of "calories in, calories out" does not seem to work for me.