Here's the deal: Yes, your metabolism affects your size, and the faster your personal motor runs, the more calories you'll burn. But the truth is, a slow metabolism isn't the real reason you're packing on pounds. You are the reason.
As a general rule, arrive at the airport no later than two hours before your domestic flight is scheduled to depart. This is somewhat later than the typical suggestion of three hours for an international flight.
In general, the airlines and the Transportation Security Administration recommend that passengers arrive at the airport at least 90 minutes before domestic flights, including those to Hawaii and Puerto Rico. This allows ample time for you to check in for your flight, check baggage and go through security screening.