While you can’t “break” your metabolism, excessive and repetitive periods in a prolonged hypocaloric state can leave your metabolism “depressed”. If you’ve eaten or exercised yourself into a corner, read on.
Our bodies are constantly striving to maintain equilibrium, and our metabolism quickly adjusts to balance (counter, resist) changes in energy intake or expenditure. This is why the common advice of EAT LESS MOVE MORE runs out of steam pretty quickly. Especially for those that have already been taking that approach for a while, or has already seen significant body re-composition.