If your body is working overtime to generate energy, it’s also expending it faster than normal and quite literally consuming itself in the effort. The message this sends to your brain is that your body is starving. When your brain thinks your body is starving, it starts retaining as much fat as possible to ensure that there will still be enough fuel to generate energy for as long as possible.
What’s the lesson to be learned here? Dropping calories is not among the most effective or efficient ways to lose weight. Not getting enough calories can lead to weight gain. How much weight is dependent on where the few calories you’re taking in are coming from.