With regards to weight loss, I've been really surprised at the hidden calories in food.
For instance, I was working in the office and wanted to buy what I thought was a healthy option. It was a very tiny chicken and salad wrap. I calculated the calories from the kilojoules listed on the packet and found it was one third of my daily allowance. And it was so small that a guy might even have had two! So really start to look at the calorie content of foods you buy.
Cruises are deadly for diets. I'd really think about how to manage that before you go. I've just returned from a four day one and despite exercising in the gym and doing two energetic Zumba classes I still gained weight! After two days I then totally cut back on food. Just yoghurt (no fat no fruit kind) plus a banana for breakfast, a boiled egg and protein shake for lunch (I'd brought some with me) and then just two courses (appetiser and soup) for dinner.
It's the coffees, multiple course meals and of course alcohol that will do you in. Just too easy to eat. You can almost see people getting heavier by the day.