Does a fast metabolism do this? a fast metabolism makes the thyroids work faster than they would ideally. shouldn't this mean that a fast metabolism will make someone lose energy fast? the thyroids must work faster than normal because the metabolism

Not quite: It's probably the other way around. If fast, average, or slow metabolism describes the rate a person uses up energy (fuel) when not running around doing much, then he either has a genetic issue that makes him use more fuel, is on a medication (legal or not) that does that, or has higher thyroid hormone output that causes more fuel consumption.