I lose weight very slowly and had to think carefully about being sensible on holiday last week. I had lost 2lb when I came back so was delighted.
Thought it might be useful to post what I had done.
I knew the area and hotel we were going to so knew what the menu would be like (delicious) and knew where the potential for walking was. Made sure my husband knew I would be walking every day and I be happy to walk alone on any occasion that he didn't want to join me.
Decided before hand that I would not be eating any desserts. Also only one small glass of red wine daily. Additionally would not eat the beautiful full Irish breakfast and instead would have porridge, full fat yogurt and seeds or salmon fillet, truly lovely.
I found this enabled me to manage my expectations and it wasn't difficult to stay with my decisions. Probably enhanced the holiday if anything. My only lapse was to have a cheeseboard one lunchtime, but even that came with so much fruit it was fine.