Ozempic and diet: Are there any foods you should avoid?

Why does the body react to certain foods during medical treatment?

The medicines used to treat overweight and obesity – known as GLP-1 and GLP-1/GIP analogues such as semaglutide and tirzepatide – contain substances that affect appetite regulation. They reduce appetite and increase feelings of fullness by acting on the brain’s hunger and satiety centres. These medicines also slow gastric emptying, meaning that food stays in the stomach for longer and you feel full for longer.

However, how quickly the stomach empties is influenced not only by the medication itself but also by the type of food you eat and how meals are structured. In combination with Ozempic (semaglutide) or Mounjaro (tirzepatide), certain foods may therefore remain in the stomach for longer and cause increased gastrointestinal discomfort. Which foods cause symptoms varies from person to person, so you may need to try different approaches to find what works best for you. By adjusting your diet and meal patterns, these symptoms can often be both prevented and alleviated.

Prevent side effects through changes in eating habits

Side effects such as nausea, constipation, diarrhoea and heartburn can often be prevented both by increasing the medication dose gradually and by adapting what you eat. Here are some strategies that many people find helpful:

Get to know your new sense of fullness

At the start of treatment, it can be difficult to interpret your body’s signals for when to start or stop eating. Try to notice when you begin to feel full and pause before you become overly full – this can make a big difference to how you feel after a meal. This reduces the risk of discomfort that can occur when you eat faster than your satiety signals can respond, or when portions are too large.

Eat regularly

A regular meal pattern helps the body establish a good eating rhythm, reduces sugar cravings and keeps energy levels more stable throughout the day and evening. Try to avoid eating close to exercise or bedtime, as this often increases the risk of nausea and other symptoms. Eating regularly also supports a healthy diet during treatment.

Eat smaller portions

Because gastric emptying is slower during treatment, large portions at one time can sometimes lead to nausea or vomiting. If you are used to eating larger portions because you previously struggled to feel full, it can help to reduce portion sizes, for example by using a smaller plate. You can also start with a smaller portion and take more if needed. It is common for the eyes to want more than the stomach can actually tolerate.

Eat slowly

Eating slowly makes it easier to notice feelings of fullness in time and can therefore reduce the risk of gastrointestinal discomfort during meals. Take smaller bites, put your cutlery down from time to time, and allow the meal to take time (ideally around 20 minutes).

Prevent side effects through food choices

No foods are “forbidden” during medical treatment for overweight and obesity. However, some foods are more likely to worsen gastrointestinal symptoms during treatment with GLP-1/GIP analogues such as semaglutide and tirzepatide. This does not mean that everyone reacts to them, but it can be helpful to be extra mindful when your stomach is more sensitive than usual.

Common foods that more often cause discomfort include:

Fried and high-fat foods

Fried and fatty foods, such as sausages, pizza, rich sauces, chips, breaded dishes, pastries and ice cream, can remain in the stomach for longer, especially during treatment with medicines like Ozempic and Mounjaro, when gastric emptying is already slower. For some people, this can increase the risk of nausea, heartburn and other gastrointestinal symptoms, although reactions vary between individuals. It may therefore be helpful to be cautious with or limit these foods when your stomach is more sensitive.

Fat- and energy-dense foods can also make weight loss more difficult, as they often provide less satiety and may lead to eating more than intended.

Tip: Choose grilled, oven-baked or boiled foods instead of fried or heavily pan-fried dishes when you want to reduce the risk of discomfort.

Spicy foods

Spicy foods such as chilli, hot sauces and strong spice blends can irritate the gastrointestinal tract and, in some people, increase the risk of heartburn, particularly when gastric emptying is slower during treatment.

Tip: If you notice that you react to spicy foods, try using milder seasonings and gradually reintroduce stronger spices as gastrointestinal side effects improve.

Gas-producing foods

Some foods are known to increase gas production, which can be more noticeable during treatment as gastric emptying is slower and the gut may be more sensitive. These include beans, lentils, onions, garlic and various types of cabbage such as cauliflower, broccoli and Brussels sprouts. Carbonated drinks can also contribute to increased gas.

Tip: Start with small amounts to see what you tolerate. Many people can manage these foods in smaller portions. If symptoms persist, temporarily reduce or avoid gas-producing foods and try reintroducing them once gastrointestinal side effects have eased.

Larger amounts of alcohol

Alcohol in combination with the medication increases the risk of gastrointestinal symptoms such as nausea, heartburn and diarrhoea. You may also feel the effects of alcohol later because gastric emptying is slower. If you have also lost weight, you may tolerate less alcohol than before. Drink slowly and be more cautious with quantities.

Tip: Try alcohol-free alternatives, or choose a light or zero-sugar carbonated drink if you want something a bit more festive.

A rapid increase in fibre intake

Fibre – found in vegetables, root vegetables, fruit, berries, legumes, wholegrains and seeds – plays an important role in gut health. However, a rapid increase in fibre intake during treatment can lead to gas, bloating or constipation, especially if fluid intake is insufficient.

Tip: Increase fibre-rich foods gradually so your gut has time to adapt, and make sure you drink plenty of water.

If dietary adjustments are not enough

In some cases, adjusting food and drink is not sufficient to reduce side effects. The treatment may then need to be adjusted, for example by lowering the dose, extending the time between dose increases, or changing how the dose is escalated. Such changes should always be made in consultation with a doctor to ensure safe and sustainable treatment.

What a healthy, nutrient-dense diet includes

During medical treatment for overweight and obesity, it is especially important to plan meals that support both your treatment and your wellbeing. As portion sizes often become smaller during treatment, the food you eat needs to be nutrient-dense. A healthy diet is primarily based on plenty of vegetables, fruit, lean protein sources, wholegrains and healthy fats such as omega-3. This type of diet provides good satiety, supplies essential nutrients and reduces the risk of nutritional deficiencies. A nutritious, healthy diet also helps maintain stable energy levels and supports both weight loss and overall wellbeing.

Prioritise protein

Protein is the most satiating macronutrient and helps keep hunger under control. It is also essential for preserving muscle mass during weight loss, which plays a key role in metabolism and long-term health. Protein is found in foods such as chicken, fish, lean meat, eggs, legumes, cottage cheese, quark, tofu and tempeh.

If you feel full quickly, it may help to start your meal by eating the protein first, to ensure adequate intake even with smaller portions.

A complex disease with increased risk of type 2 diabetes

Obesity is a complex, chronic disease influenced by biology, behaviour and lifestyle. A high proportion of body fat increases the risk of several conditions, including type 2 diabetes, cardiovascular disease, osteoarthritis and certain cancers. Having access to support when questions arise can make a significant difference to safety, motivation and treatment outcomes. It is therefore important to receive the right support throughout treatment.

If you have questions about the medication, diet, side effects or lifestyle changes, it is always best to contact your doctor or treatment team. They can help you find a sustainable approach tailored to your needs.

Treatment with Ozempic once weekly for type 2 diabetes and obesity

Ozempic is a medicine used to treat type 2 diabetes and contains the active substance semaglutide. It is a prescription medicine taken as an injection once weekly and is available in several doses, allowing the doctor to tailor treatment to your individual needs.

Ozempic helps lower blood glucose by increasing the body’s own insulin release when needed and by slowing gastric emptying. Treatment should always be combined with a healthy diet and regular physical activity for best results.

It is important to follow your doctor’s instructions carefully before starting Ozempic, and to contact your doctor if you have any questions or concerns about the medicine or your treatment.

In some cases, Ozempic may be prescribed off-label to support weight loss. This means the medicine is used outside its formally approved indication, based on clinical experience and research showing that semaglutide can also affect body weight. Such prescribing is always carried out by a licensed healthcare professional following an individual medical assessment of needs, health and treatment goals.

How other medicines may affect your treatment

When using medicines such as Ozempic (semaglutide) or Mounjaro (tirzepatide), it is important to be aware that treatment can affect, or be affected by, other medicines. For example, combining these medicines with certain diabetes drugs such as sulfonylureas or insulin can increase the risk of low blood sugar, and doses may need to be adjusted. Always inform your doctor about all medicines you are taking, including over-the-counter products and herbal remedies.

Information about drug interactions is included in the patient information leaflet – always read this carefully. If you are unsure or have questions about your medicines, consult your doctor to ensure safe and effective treatment.

Summary

Treatment with semaglutide and tirzepatide can be an effective support for weight loss and improved health. At the beginning of treatment and during dose increases, gastrointestinal side effects such as nausea, heartburn, diarrhoea and constipation may occur. These are usually mild and can often be reduced by slow dose escalation and by adjusting the diet, paying attention to foods that trigger symptoms.

These medicines affect appetite regulation and slow gastric emptying, meaning that certain foods may remain in the stomach for longer and cause discomfort in some people. By learning to recognise your new sense of fullness, eating slowly, choosing smaller portions and maintaining regular meal patterns, many people can prevent symptoms. It may also help to be mindful of foods that commonly cause discomfort, such as fried and fatty foods, spicy foods, gas-producing foods, larger amounts of alcohol and a rapid increase in fibre intake.

A nutrient-dense diet rich in vegetables, fruit, wholegrains, lean protein sources and healthy fats is especially important when portions become smaller, both to meet nutritional needs and to support weight loss and wellbeing. Protein is particularly important for satiety and for preserving muscle mass during weight loss.

Obesity is a complex, chronic disease associated with increased risk of conditions such as type 2 diabetes and cardiovascular disease. Receiving appropriate support throughout treatment is therefore essential. If you have questions about the medication, side effects or lifestyle changes, always contact your doctor or treatment team, who can help you adapt your treatment in a safe and sustainable way.

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