Date of document April 2023
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1General information

If you are healthy, you usually don't even notice your body. Only when one falls ill do sometimes drastic changes occur. This is an old story of evolution that has worked for millions of years, but still works well today. When a serious injury or illness occurs, our body down-regulates alertness and concentration, physical activity and performance, and the ability to enjoy and communicate, in order to be able to put as much energy and resistance to the illness as possible. In such a situation, it is important to provide the body with sufficient nourishment and to exercise it carefully, but not to weaken it with unnecessary great exertion or strain on the immune system.

Once the injuries - e.g. from major surgery, radiation, and drug treatments - have healed and the disease has been overcome, it takes some time, but the body soon sets out to regain its pre-existing strength and abilities. Sometimes longer-lasting dysfunctions may persist in some areas, but usually our bodies are prepared to re-establish a healthy functioning whole.

After cancer treatment, it is beneficial to support the body and the inner forces and to avoid disruptive stresses as much as possible. A healthy lifestyle contributes significantly to this:

  • regular strenuous, but not overloading, physical exercise to build and strengthen muscle and cell mass;

  • a balanced and varied diet, but avoiding excessive amounts of food that unnecessarily increase body fat stores;

  • effective stress management, so that you can enjoy and take pleasure in some things every day, and avoiding chronic stressful situations that can unbalance the metabolism and weaken the immune system.

2Good to know

An important message for patients after cancer is: The recommendations for a healthy, balanced diet also apply to you!

If you have been eating healthy so far, please continue to do so. Try to eat a balanced diet. If you find this difficult, a qualified professional can help you put together the right diet for you.

2.1Eating, drinking and exercising after cancer - What is a healthy lifestyle?

The World Cancer Research Fund's (WCRF) international group of experts has been refining lifestyle suggestions aimed at reducing cancer risk since the 1990s. No behavior can prevent cancer with certainty, but the following suggestions can strengthen defenses and provide vitality. Eating and exercising are always about enjoyment. Health recommendations never apply so absolutely that you can't deviate a little now and then; but it helps to follow the suggestions for the most part. You should feel good in your life and have as little fear as possible of doing something wrong.

2.2Recommendations of the World Cancer Research Fund

2.2.1Make sure you have a healthy body weight

Try to keep your body weight in the normal range. The body mass index (BMI) relates weight to body length and should preferably be between 21 and 23.

Calculate BMI: Weight (in kilograms) / Height (in meters) ²

Thus, a good weight would be 60 kg at a height of 165 cm, 67 kg at 175 cm and 75 kg at 185 cm. In various studies, a correlation between severe overweight (BMI over 30 kg/m²) and cancer has been observed. In relation to all types of cancer, severely overweight women were found to have a 90% increased risk of cancer, and overweight men were found to have an approximately 50% increased risk. It was also shown that a very high BMI increases the risk of cancer recurrence, e.g. for breast cancer or prostate cancer.

2.2.2Eating, drinking and exercising after cancer - What is a healthy lifestyle?

Build at least 30 minutes of moderate exercise (e.g. brisk walking) into your daily routine. To improve your performance, get either 30 minutes of intense exercise (e.g., jogging) or 60 minutes of moderate exercise or other activity every day. Climbing stairs is better than riding an elevator; ride a bike rather than a motor vehicle! For more information on physical activity, see AYApedia Exercise and Sport.

2.2.3Eat very caloric foods only rarely

Avoid sugary drinks and reach for fast food as little as possible.

2.2.4Prefer plant foods

Fruit, vegetables, beans, peas, lentils, potatoes and cereal products

  • The following applies to vegetables and fruit: Eat 3 portions of vegetables and 2 portions of fruit daily (rule of thumb: one portion= 1 handful).
    Practical tip: Eat a portion of vegetables with every main meal and choose vegetables as well as fruit as a snack in between meals.

  • For peas, beans, lentils as well as cereal products, eat these foods at every meal and prefer whole grain cereal products

2.2.5Enjoy meat only in moderation

Your weekly meat consumption should not exceed an amount of 500g. You should be especially careful with the consumption of processed meat (e.g. smoked meat, sausage products).

Several studies have concluded that larger amounts of red meat (e.g., beef or pork) appear to slightly increase the risk of cancer.

2.2.6Limit your alcohol consumption

Men should drink no more than two glasses of alcohol per day and women no more than one glass of alcohol.

2.2.7Avoid cured, salted or salty foods

Likewise, you should not eat moldy foods (especially moldy grains or moldy legumes).

2.2.8Dietary supplements are not recommended

In the context of cancer prevention, you should and can meet your nutrient needs (except in medically justified exceptional cases) exclusively through your normal diet.

There is no reliable evidence that taking vitamin or multimicronutrient supplements containing a combination of different vitamins, minerals, and trace elements reduces the risk of developing cancer; it is possible that these supplements may even slightly increase the risk of tumors.

2.3Special recommendations after high-dose therapy or stem cell transplantation

During and after cancer treatment, food safety is very important because the immune system is often severely weakened by cancer treatment and the body is more susceptible to foodborne illness.

The focus here is on food hygiene. If the immune system is weak, the basic rules of kitchen hygiene must be observed even more consistently than usual. This concerns the safe preparation and handling of food (see the list below).

A so-called strict "low-germ" diet, in which fresh fruits and vegetables are prohibited and only cooked or boiled foods are allowed, is no longer consistently recommended today. Clinical studies over the past 10 years have failed to show any clear advantage of such a diet or any reduction in the number of infections. However, in cases of pronounced immune deficiency, especially with very low neutrophil counts (a group of white blood cells important for fighting bacterial infections), many major centers recommend avoiding foods that have a particularly high risk of being contaminated with dangerous germs (see the following list). A strict low-germ diet is therefore usually only recommended in the immediate aftermath of stem cell transplantation until the blood counts (especially the neutrophil count) have recovered. After discharge from the hospital, these strict restrictions are usually no longer necessary. Rather, it is important that you consume sufficient energy, nutrients and fluids according to the basic rules listed below.

It is important to note that to date there are no uniform clear and detailed guidelines for nutrition after stem cell transplantation, either globally or nationally. Thus, guidelines may differ somewhat from clinic to clinic. However, the basic principle remains: regular and complete kitchen hygiene and avoidance of high-risk foods. Therefore, ask your physician regarding the individually determined or necessary measures. Furthermore, you should remember that in every phase of the disease it is crucially important for a good physical condition and resistance that you take in sufficient energy and the vital nutrients. Excessive dietary restrictions can jeopardize this.

2.3.1Some important rules

  • You can eat all animal products that are fully cooked (meat, eggs, fish) or pasteurized (milk, cheese, dairy products).

  • You may also eat fruits and vegetables raw as long as you have prepared them sufficiently:

    • If the skin is smooth and not from the earth-> wash very thoroughly, peel usually not necessary (eg, tomatoes).

    • In case of rough skin or originating from the ground (e.g. carrots) -> wash thoroughly and then peel.

  • Produce that has a rough skin and/or grows close to the earth and cannot be cooked or peeled (e.g., berries, salads) should be avoided as long as neutrophil counts are below 1,000/µl, but are allowed at higher neutrophil counts after thorough washing;

    • Caution: berries not from the forest

    • Salads not packaged from the supermarket.

If necessary, talk to your doctor about further details.

2.3.2Hygiene rules:

  • Wash fresh fruits and vegetables thoroughly under running water (30 seconds!), even if you peel them afterwards

  • Always clean kitchen utensils including boards, sponges, cloths well and boil them if necessary. Equipment that comes into contact with raw meat (especially poultry) should always be cleaned hot and with detergent (preferably in the dishwasher).

  • Store meat, sausages, fish and seafood only in the refrigerator or freeze these foods

  • keep raw meat separate from other products during storage and preparation

  • when cooking, always ensure sufficient temperature and cooking time. Animal products should only be eaten cooked through.

  • Refrigerate and freeze food as needed

2.3.3Avoid the following foods:

  • Avoid raw or insufficiently cooked or fried meat and raw fish

  • Avoid raw and undercooked eggs or foods that contain raw eggs (e.g. homemade mayonnaise or raw cake batter)

  • Avoid non-pasteurized beverages (e.g. milk)

  • Avoid soft, unpasteurized cheeses and soft mold or blue cheese (e.g. Brie, Camembert, Roquefort, Stilton, Gorgonzola).

  • Avoid raw milk yogurt and raw milk cheese

  • Avoid salad bars and salad buffets that are open to the public (e.g. in supermarkets, canteens or restaurants)

  • Avoid raw sprouts (e.g. alfalfa sprouts or bean sprouts)

  • Avoid well or spring water (unless it has been tested, filtered, or boiled for one minute before drinking)

2.4Information on "Cancer Diets: Fasting and low-carbohydrate diets

Fasting involves supplying the body with no or very little food and energy (e.g. tea or vegetable broth). A low-carbohydrate diet (also known as "low carb"), on the other hand, aims to avoid carbohydrates (especially sugar) for the most part and instead eat mainly foods rich in fat and protein. The idea behind this is that tumor cells can obtain energy particularly well from sugar but hardly at all from fat, and that they should be "starved out" by depriving them of sugar or carbohydrates. But while it is sometimes actually possible in cell culture to cause some tumor cells to die by depriving them of sugar, there is as yet no evidence that this also works for a tumor in the human body. One of the reasons for this is that sugar is always circulating in our blood and the tumor cells take up enough of it to survive, even when blood sugar is low. However, especially with fasting but also with a low-carbohydrate diet, which is often difficult in terms of taste, there is a great risk of weight loss. This is very problematic because many cancer patients already suffer from a lack of appetite and weight loss. Weight loss reduces body activity and defenses, and thus resistance to the tumor disease and tumor therapies.

Currently, several clinical studies are being conducted nationally and internationally on the importance of short-term fasting during chemotherapy in selected patient groups and under close medical supervision. However, the results of these studies remain to be seen before medically validated recommendations can be made.

In summary, there is as yet no scientific evidence for an effective "cancer diet" and it is not possible to "starve" a tumor. Therefore, be wary of providers who advertise a supposed "cancer diet" and rather discuss your diet carefully with a nutritionist (e.g. a dietician or nutritionist) during cancer therapy.

3Tips and tricks

For suggestions on how to prepare healthy food, see Nutrition Recipe Ideas.

3.1Tips for adequate fruit and vegetable intake at home and on the road

  • Raw food/fruit plate in the evening instead of salty or sweet snacks

  • Integration of vegetables in the midday meal (e.g. broccoli casserole, side salad), in the evening meal as a salad garnish (cucumber/tomato with the bread meal) and for in between meals as vegetable sticks

  • Integration of fruit as a dessert after lunch (e.g. peach curd) and as a

  • Snack on the go (apple/ pear)

  • Vegetable sticks for on the go at school or for work (e.g. kohlrabi, carrots, cucumber)

  • Self-prepared smoothies (versatile selection of fruits and vegetables possible)

  • Alternatively, 1 glass of juice instead of 1 fruit meal (make sure it is 100% fruit juice).

3.2Dietary fiber

  • Foods high in fiber and low in salt:
    Whole grain bread, flaxseed, wheat and oat bran, various fruits (blueberries, strawberries, apple), legumes (beans, chickpeas, lentils).

Important: Do not forget to drink! Because only with sufficient liquid the dietary fibers can develop their positive effect.


  • Advantages of vegetable fats over animal fats:

  • Prevention of cardiovascular diseases through the supply of essential fatty acids (only polyunsaturated fatty acids, which the body cannot produce itself, therefore the intake through food is important)

  • can have a positive effect on blood lipid levels and cholesterol levels

  • rich in fat soluble vitamin E


  • Always carry a small bottle with you (e.g. in your handbag/backpack)

  • Leave drink in sight during work/lecture to be reminded to drink

  • Consume preferred low-energy drinks, provide variety

  • In summer, tea can also be enjoyed cold and refined by additions, such as lemon or lime slices

4Further links and information


  1. World Cancer Research Fund / American Institute for Cancer Research (eds.). Diet, Nutrition, Physical Activity and Cancer: a Global Perspective. Continuous Update Project Expert Report 2018. Available at dietandcancerreport.org (English summary of 3rd expert report). German summary of 2nd expert report: diet, physical activity, and cancer prevention: a global perspective. 2008.[Internet] [cited 08/20/18]. URL: https://www.wcrf.org/sites/default/files/german

  2. Eating and drinking during cancer therapy. 2015. Infothek, article number 123037, Deutsche Gesellschaft für Ernährung e. V., Bonn; info@dge-medienservice.de

  3. Leukemia and Lymphoma Society (ILS) (ed.) Diet Guidelines for Immunosuppressed Patients. 2018.[Internet] [cited 08/20/18]. URL: https://www.lls.org/managing-your-cancer/diet-guidelines-for-immunosuppressed-patients

  4. Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute (RKI): Hygiene requirements for the medical care of immunocompromised patients - Recommendation of the Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute (RKI), Bundesgesundheitsblatt 2010, 53:357-388.


Gender terms used in this text represent all gender forms.

7Experts' Affiliations

Dr. med. Jann Arends
Universitätsklinikum Freiburg
Klinik für Innere Medizin I
Hämatologie / Onkologie
Hugstetter Str. 55
79106 Freiburg
Prof. Dr. med. Hartmut Bertz
Prof. Dr. med. Sebastian Theurich
Klinikum der Universität München
Medizinische Klinik und Poliklinik III
Campus Großhadern
Marchioninistr. 15
81377 München
Julia von Grundherr
Universitätsklinikum Hamburg-Eppendorf
Hubertus Wald Tumorzentrum
Universitäres Cancer Center Hamburg (UCCH)
Martinistr. 52
20246 Hamburg

8Disclosure of Potential Conflicts of Interest