Mounjaro users urged to do one thing before Christmas by doctor

For people using Mounjaro, the pressure feels even heavier as many worry that a traditional Christmas feast might undo their hard-earned progress or leave them feeling unwell. 



Wondering if you can safely indulge this festive season while on Mounjaro?

You don’t have to be nibbling on carrots on Christmas Day. Dr Crystal Wyllie at ZAVA says: “This season should be joyful, not spent worrying about every bite. Using a 16/8 intermittent fasting window ahead of your big meal is a gentle way to give your stomach the break it needs before a richer meal.

“It’s an easy method of fasting for 16 hours and eating within an 8-hour window, which is not as difficult as it sounds if you time it right.”

If your Christmas Day lunch is between 12 pm to 2 pm, here’s when to stop eating: “Stop eating by 8 pm the night before if your lunch is at 12 pm, it’s completely manageable if you have an early Christmas Eve dinner and avoid late-night snacks – you’ll wake up only a few hours away from breaking your fast.

“If your lunch is at 1 pm, stop eating an hour later by 9 pm and if it’s at 2 pm, aim to finish by 10 pm.

That said, fasting should not feel punishing. If you wake up feeling low on energy or dizzy, shorten the window to 14/10 or even 12/12, and have something light like a piece of bread or yoghurt in the morning.

“Intermittent fasting works because it helps reduce ‘meal stacking’, a common issue for people on Mounjaro, where food tends to remain in the stomach longer.

“Giving your digestive system time to reset makes it more tolerant of richer foods, helps stabilise blood sugar before a large meal, and importantly, removes the sense of guilt which often comes with indulging while on medication.”

It’s worth noting, intermittent fasting can be a helpful strategy for many, but it may not be suitable for everyone.

People with certain medical conditions, those prone to low blood sugar, or anyone taking medications that need to be taken with food, should consult their healthcare provider before trying this approach.

Radio 4 journalist asking what Mounjaro users will do at Christmas? The same as any other healthy slim person I guess. Seemingly this a week long theme.

— Alastair Muirhead 🍃 (@Tairmuir) December 15, 2025

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Remember that even with a fasting strategy, the way you eat your Christmas lunch still plays a key role, Dr Crystal explains: “It’s crucial not to rush through your meal. Eating slowly allows your body to register fullness more effectively, reducing the risk of discomfort or bloating at the end of the meal.

“Take the time to enjoy each course, pause between bites and pay attention to your body’s signals. The goal is to feel satisfied and fulfilled, not overly stuffed.

“While enjoying your festive favourites, you can also gently balance your meal by including foods that support digestion.

“Brussels sprouts are a good ally to your festive roast, along with roasted carrots and green beans which are all high in fibre. At the same time, go a little lighter on very heavy foods like creamy sauces or extra-large helpings of stuffing if you know they tend to leave you feeling sluggish.

“The key is moderation and mindful eating so your Christmas meal feels enjoyable and stress-free.”

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Diving onto the couch straight after your Christmas feast? Dr Crystal Wyllie at ZAVA shares her top recovery tips after a heavy meal:

”Lying down immediately after a big meal is a no-no. When you lie flat or slouch in a reclined position, digestion slows and the risk of acid reflux or indigestion increases. Instead, take a gentle walk around your home or garden, even a short 10 to 15-minute stroll helps move food along the gastrointestinal tract and can regulate blood sugar levels.

“Simple stretches that open the chest and lengthen the abdomen, such as standing side bends or reaching overhead, can also improve circulation and relieve abdominal pressure. Stick to gentle movement as intense exercise immediately after eating can worsen discomfort or nausea.

“Hydration is also key. Sip water or unsweetened herbal teas such as peppermint, ginger or chamomile. Peppermint and ginger are known to reduce bloating and support digestion, while chamomile has calming properties to ease post-meal discomfort.

“Stay away from detox teas as many contain strong laxatives that can irritate the stomach and intestines – particularly for Mounjaro users whose digestion is already slower and more sensitive.”