Change the goal first. Almost everyone tries to keep dieting through a holiday, almost nobody manages it, and the giving up costs far more than the food ever did.
A kilo of fat is about 7,700 calories above what you burn. Eat 500 a day over maintenance for a week and that's 3,500 — under half a kilo. Even a genuinely indulgent week, 1,000 a day over, is under a kilo.
A week away cannot undo three months. It isn't mathematically possible, however it feels on the Monday you get back.
Maintenance has a property a deficit doesn't: you can't fail at it in a way that compounds. There's no streak to break, so there's no spiral. Trying to run a deficit at an all-inclusive means failing by day three and then not caring for the rest of the week — which is how people come back worse.
The breakfast buffet is the biggest trap on any all-inclusive. You're not hungry at eight in the morning — you're standing near food that's already paid for. Coffee and some fruit, then eat properly at lunch and dinner. That one change is often 600 to 800 calories a day.
Not a workout. A walk, before it gets hot. It's the easiest 300 to 400 calories you'll ever burn, it doesn't make you hungry the way hard cardio does, and you see more of wherever you are.
Decide it once at the start of the week rather than having the argument at every meal. Decisions you've already made cost you nothing. And at an all-inclusive the drinks are where it goes wrong — a piña colada is 400 to 600, and three a day for ten days is more than the entire buffet will cost you.
You'll be up two to four kilos on the scale and it'll feel like proof. It isn't — you'd have needed roughly 20,000 surplus calories to gain three kilos of fat, and you didn't. It's salt, carbohydrate and water, and it's gone within a week of normal eating.
What undoes people isn't the holiday. It's deciding on that Monday that it's all gone.
Leeway is a free tool that does this arithmetic for you. Put what's coming up into the week and it spreads the cost across the days around it, with a floor it won't plan below.
Open the planner — freeLeeway is a planning tool, not medical or dietary advice. Calorie figures are typical estimates and vary by brand, measure and recipe. It isn't suitable if you have, or have had, an eating disorder or a disordered relationship with food. If you're unsure what a safe calorie target is for you, speak to a GP or registered dietitian first.