It has all the hallmarks of a holiday romance: falling madly in love, swearing eternal allegiance, then abandoning it as soon as you touch down back home, with niggling feelings of guilt and regret.
But a trip to a health resort doesn't have to end in broken promises and recriminations.
There are ways of keeping alive that passion for healthy living you felt so strongly while away and turning it into a stable relationship with healthy eating, exercise, weight maintenance and good stress management that could last a lifetime.
"We view your stay here as just the beginning of your health journey," says Nadia Phisetsutthikun, wellness manager of one of the world's leading luxury health resorts, the Amatara in Thailand's Phuket, which is leading the way in working to keep its clients connected.
"We aim to give you the knowledge to know how to translate the experience here into your own life, and we hope your time here will be your inspiration to continue a healthy life back home. There's no point in coming to us and being healthy for just a week. We want you to apply the lessons you've learnt to your own life."
I like people to take the knowledge away with them so they can put it in place when they get home.Holistic wellness specialist Ken Rego
That's all very well, but too many of us know how quickly our good intentions can fade. We leave the spa positively glowing from all the fine food, quality rest, meditation, yoga and cardio, then we get home and eat some chocolate and drink half a bottle of wine to reward ourselves for having been so good.
There's a sleep-in the next morning rather than getting out for that early walk because we really do need the rest. And immediately our stress-o-meters hit double figures because we're so behind with work, and are back among all the bad habits that sent us off to a health retreat in the first place.
But the message coming through more and more today is that it doesn't have to be that way. At the Amatara, for instance, there are several strategies to keep the customer engaged beyond the stay.
In terms of exercise, the classes contain a lot of one-on-one tuition to explain how to do the moves properly by yourself and plenty of encouragement to practise and improve. "When you get home," the pilates instructor Dan tells me, "make sure you do this exercise as soon as you get out of bed in the morning, then again in the shower, then after breakfast …"
Yoga teacher Luna is similarly persuasive. "Yoga is wonderful for flexibility and posture and should be part of everyone's schedule," she says. "But it doesn't have to be hard. You can stretch any time at home, in front of the TV, whenever."
If you really loved a particular class, but can't find a similar one near your home, they'll often scour the neighbourhood for you to make recommendations. They'll also send over helpful YouTube links on how to do particular exercises, as well as welcoming any questions, by phone or email, you have when you return home.
Food is a huge part of a health retreat stay and the Amatara runs cooking classes to show you how to reproduce some of its best dishes and prepare food more healthily. There are talks too on the importance of macro-nutrients and nutrition, covering everything from why it's important to eat your vegetables first, before the protein, to powerful secrets of weight loss with intermittent fasting.
Holistic health and wellness specialist Ken Rego emails over bullet points of his talk to guests when they've left, and sends tips on how to avoid snacking or false hunger cravings – like drinking more water, or water with a dash of apple cider vinegar. He also makes his own YouTube video dispatches for past guests.
"I like people to take the knowledge away with them so they can put it in place when they get home," he says. "You're aware that when people are here, they're on vacation but they often want to make it part of their lifestyle, and it's our role to help them with that."
Spa treatments like massage and wraps are always a big part of any retreat, and even here the experience is aimed at helping beyond the stay. You're encouraged to try a range of treatments to find ones you love, and will seek out later. There's even a lesson on how to master the skills of massage for a partner or friend.
And, finally, there's the coup de grace: personal contact.
At the departure wellness consultation Nadia assesses my progress, talks through what I've enjoyed the most and learnt, and tells me that guests at any time in the future can phone or email to ask for guidance or support.
"And I will be phoning or emailing you too, usually in one month then in three, to see how you're going," she says. "Our role is to make you feel passionate about your health, your food and your exercise, and making that passion continue."
Jetstar flies direct to Phuket.
Amatara Wellness Resort – package rates for four days and three nights, including accommodation, wellness consultations, three meals a day, treatments and activities, start from 41,800 Thai baht a person twin-share (excluding VAT, tax and service charges). There are two special offers currently running: bonus nights for stays from November 1 to December 25; or free flight with minimum five-night booking from now till December 25. The Amatara Wellness Resort, Cape Panwa, Phuket, Thailand, Phone (+66) 7631 8888. Book via Amatara direct or through a travel agent.
Sue Williams was a guest of Amatara Wellness Resort