Rather than feeling like you can never indulge or be social, be mindful of your choices. Pay attention to how much food you put onto your plate. You likely already know which foods you can load up on (think green veggies) and others that require more moderate portions and self-restraint (like the guacamole and tortilla chips).
Too many times people return from vacation having had a great time, but also being down on themselves due to letting unhealthy habits dominate. People tend to overeat, drink more, and skip their work outs. It sucks to get away only to return feeling worse physically and emotionally than when you left! My friend Em and I are living proof that you can go on a vacation that is both healthy AND fun!
For as long as I can remember, I've been told that it's paramount to load up on carbs before any kind of physical activity. As I've gotten older, wiser and tried things for myself, I've realized that this is complete overkill. In most cases, eating carbs before working out is like filling up a near-full gas tank and watching excess gas spill all over the ground.