Unfortunately the human body is quite a bit more complicated than that and a single article on examine.com is woefully inadequate at capturing the complexities.

Unfortunately the human body is quite a bit more complicated than that and a single article on examine.com is woefully inadequate at capturing the complexities. While people's metabolism doesn't seem to vary too much from person to person, it does tend to vary a lot within the same individual based on lifestyle choices. Whether I choose to eat or not, or choose how much to eat, my metabolism can vary. When you consider your glycogen reserves, carb vs fat metabolism, insulin, ghrelin and other hormones, you get a rather complex machine. And what's really frustrating is that you are technically correct, in a sense. Eat fewer calories than you burn and you will lose weight. But that simplification borders on the dangerous. What's missing is that your body is not some passive observer, but an active participant, trying its best to help you survive. Your body is amazingly good at adjusting how much you burn. When you cut calories, say 500 a day, your body will tend to compensate by burning a little less by reducing its temperature, by reducing fidgeting, by reducing your mood even! You'd need to cut 500 calories ABOVE that difference. So you end up having to cut closer to 750-1000 calories per day to get the same effect. Whereas when you fast, your metabolism rather obnoxiously tends to rise. It ends up being healthier (and much easier) to eat 3500 calories less in one go, rather than splitting the difference across 7 days.