A major health alert has been issued, affecting millions of people across the UK, regarding certain foods to avoid this Christmas. Eating these foods could cause several side effects, such as bloating, reflux, wind, sulphur burps, nausea, diarrhoea, and occasionally vomiting.

With December 25 only a couple of weeks away now, many people are making a start on their Christmas dinner food shop. Some of the most common items bought and eaten around this time of year include pork products, such as pigs in blankets. Others also include roast potatoes, soft cheese and various meats - see full list below.

However, millions of people are being advised to avoid eating these popular food items due to a significant health concern. According to the latest figures, one in 20 Brits (2.5 million) is reportedly taking weight loss jabs in 2025, such as Mounjaro and Wegovy.

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When using Mounjaro and Wegovy, it's best to avoid foods that can exacerbate side effects or slow down weight loss. This mainly includes highly processed foods, sugary snacks, refined carbs, and too many unhealthy fats, since they can lead to nausea, blood sugar spikes, and stomach problems.

It's also a good idea to limit your intake of alcohol and caffeine. Instead, try to eat lean proteins, fibre, fruits, and vegetables to help the medications work better and to reach your goals. The pressures around Christmas indulgences are expected to bring on a lot of stress and anxiety, with many unsure of the foods they can eat and the ones they should avoid.

Dr Crystal Wyllie, MBBS, who works as an NHS GP and a doctor at online medical practice ZAVA, has listed the festive foods that GLP-1 users should consider avoiding this Christmas. She has also explained the science behind why.

Dr Crystal Wyllie says that those using GLP-1 weight-loss medications, such as Mounjaro and Wegovy, often find that rich, high-fat, or very sugary foods trigger side effects. She says this includes nausea because the drugs naturally slow stomach emptying.

She said: "Experiencing side effects is completely normal and very common on GLP-1 medications. They slow digestion and alter hunger signals, so mild digestive discomfort is expected for many people."

She also explained that when the digestive system is already moving more slowly, heavy festive foods can sit in the stomach for even longer than usual. "In turn, this can lead to the well-known and very common symptoms of bloating, reflux, wind, sulphur burps, nausea, diarrhoea, and occasionally vomiting."

The doctor added: "Avoiding or reducing the amount of these trigger foods can help keep digestion comfortable over Christmas and reduce the likelihood of unpleasant side effects that may spoil the day."

Mounjaro (tirzepatide) and Wegovy (semaglutide) are both GLP-1 receptor agonists and are medicines that you can only get with a prescription. You can't buy them at a store without a prescription. You can get Mounjaro and Wegovy through the NHS or by getting a private prescription. However, there are certain rules to follow, and you usually need to be referred to a specialist weight management service.

GLP-1 medications, which are also called Glucagon-like peptide-1 agonists, are drugs that act like a natural hormone in the gut. They help control blood sugar levels and can help people lose weight by slowing down digestion, making you feel less hungry, and boosting insulin production.

These medications are mainly used for type 2 diabetes, but more people are using them for long-term weight management. They come in the form of injections or tablets and are known to be very effective, although you should think about the cost and possible side effects.

Brits on weight loss jabs may be dismayed to hear that, despite being a Christmas dinner staple, pigs in blankets should be avoided or consumed in small portions only, Dr Crystal Wyllie says. Pigs in blankets are high in fat and salt, which sit heavily in the stomach when digestion is slowed by GLP-1 medications. The double-fat combination of sausage and bacon often worsens nausea and reflux.

• Common side effects: Nausea, bloating, reflux, stomach pressure.


• Alternatives: Lean turkey sausages or a smaller portion paired with vegetables.

Despite some chefs claiming the key ingredient to making roast potatoes ‘better’ is goose fat, GLP-1 users may also be disheartened to learn that goose fat is extremely rich, and high-fat foods take longer to leave the stomach, something jab users are already prone to. This can lead to an uncomfortable 'food sitting' feeling and sudden queasiness after eating, Dr Crystal Wyllie says.

• Common side effects: Nausea, fullness, indigestion.


• Alternative: Roast potatoes in olive oil, or a mix of roast and steamed potatoes.

Dense protein requires significant digestive effort, and large servings can overwhelm the slowed gastric emptying caused by these medications. Dr Crystal Wyllie says this often leads to discomfort or nausea after a big meal, which can occasionally cause vomiting.

• Common side effects: Bloating, nausea, stomach cramps.


• Alternative: Smaller servings of lean turkey breast or slow-cooked meats.

Soft cheeses, such as brie and camembert, contain high levels of fat and can be difficult to digest, especially after a heavy, hearty meal, according to Dr Crystal Wyllie. They commonly trigger nausea for GLP-1 users because the combination of richness and creaminess lingers in the stomach.

• Common side effects: Nausea, bloating, reflux.


• Alternative: Reduced-fat cheese, hard cheeses in small amounts, or fruit instead.

Usually paired perfectly with a Christmas pudding, brandy butter is almost entirely made up of fat and sugar, the two biggest triggers for GLP-1-related digestive upset. "The richness can overwhelm the stomach quickly, even in small amounts, and often causes immediate queasiness," Dr Crystal Wyllie says.

• Common side effects: Nausea, indigestion, stomach heaviness.


• Alternative: A lighter custard or yoghurt-based topping.

The iconic Christmas dessert, the yule log, is dense, chocolate-heavy, and often filled with rich cream, which makes it slow to digest and very sweet, two things GLP-1 users are typically sensitive to. The quick sugar spike, followed by the richness, even small slices, can cause discomfort after a meal, Dr Crystal Wyllie said.

• Common side effects: Nausea, bloating, reflux, sugar crash.


• Alternative: A small portion of dark chocolate or a sponge-based dessert without cream.