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Other PLAIN summaries
- Asymptomatic coronary artery disease
- Bone problems
- Cancer-related fatigue
- Central precocious puberty – CPP
- Chronic pain
- Craniofacial growth problems
- Dental and oral problems
- Dyslipidemia
- Eye problems
- Gastro-intestinal problems
- Hair loss
- Health promotion
- Hearing problems
- Heart problems
- Higher risk groups
- HP axis problems
- Hypertension
- Impaired glucose metabolism and diabetes
- Kidney problems
- Liver problems
- Lower urinary tract problems
- Lung problems
- Male fertility problems, testosterone deficiency and sexual dysfunction
- Mental health problems
- Neurocognitive problems
- Obstetric problems
- Overweight and obesity
- Peripheral neuropathy
- Premature ovarian insufficiency
- Psychosocial problems
- Spine scoliosis and kyphosis
- Spleen problems
- Stroke
- Subsequent neoplasms:
- Thyroid problems
OVERWEIGHT AND OBESITY
This page is part of the PanCare PLAIN summaries about late effects and recommendations for long-term follow-up care for survivors of childhood, adolescent, and young adult cancer. Click here, for more information on the PLAIN summaries.
This PLAIN summary is based on the PanCareFollowUp guideline about “Overweight and obesity” [1] , which is based on the consensus of different national guidelines.
PLAIN version 2.1: 27/05/2024
Overweight and obesity
To function properly, the body needs energy (or fuel). This energy comes from the food we eat. When we eat more than the body needs, the body stores the leftover energy as fat. This is useful, as the stored fat can be used as a reserve when more energy is needed (for example during exercise, or when you suddenly have less access to food).
It is healthy for the body to have some fat stored. However, when the body stores too much fat you become overweight or obese. This can cause a wide variety of health problems such as heart problems, stroke and diabetes. For more information on strokes, heart attacks and diabetes, please read: Strokes, Asymptomatic coronary artery disease, impaired glucose metabolism and diabetes.
The unit of measurement that helps determine if you have a healthy weight is the BMI.
To measure your Body Mass Index (BMI), weigh yourself on a scale. It is best to weigh yourself in the morning, before breakfast and without any clothes on. Also measure your height without shoes on. Then make the following calculation:
- Height (in metres) x height ( in metres) = height squared
- Weight (in kilograms) / height squared = BMI
For adults (18 years or older) a healthy BMI usually ranges between 18.5 and 25. A BMI below 18.5 or above 25 increases the risk of health problems. When the BMI is between 25 and 30, we consider someone to be overweight. When the BMI is above 30, we speak about obesity. However, there are exceptions. For example, when you are pregnant, breastfeed or have a lot of muscle mass, a BMI above 25 is not necessarily unhealthy.
| Men | Women | |
| BMI | ||
| Underweight | Below 18.5 | Below 18.5 |
| Healthy | 18.5-25 | 18.5-25 |
| Overweight | 25-30 | 25-30 |
| Obese | Above 30 | Above 30 |
There are a number of things anyone can do to get to a healthier weight or to lower the risk of being overweight and obese, such as adopting or maintaining a healthy lifestyle. For more information on taking up a healthier lifestyle, please read: Health promotion.
Body Mass Index
- With metric units: weight (kg) ÷ height2 (m)
- With imperial units: weight (lbs) ÷ height2 (inches) × 703
You can also use the BMI calculator on the website of the National Health Service of the UK (NHS).
For adults a normal BMI usually ranges between 18.5 and 25. A BMI below 18.5 or above 25 increases the risk of health problems. When the BMI is between 25 and 30, we consider someone to be overweight. When the BMI is above 30, we speak about obesity. It is important to consider that there are exceptions. For example, when you are pregnant, breastfeeding or have a lot of muscle mass, a BMI above 25 is not necessarily unhealthy.
It is important to keep in mind that the BMI score has limitations. It does not take into account how much of your weight is fat and how much is muscle mass. Furthermore, it also does not take the distribution of the fat in your body into account. That’s why healthcare professionals usually use the BMI together with other measuring systems (e.g. waist circumference) to assess your health.
Healthy lifestyle
- Having a healthy diet
- Drinking less (or no) alcohol
- Exercising regularly
- Quitting smoking (if you smoke)
Your follow-up care specialist or general practitioner may give you additional advice tailored to your individual situation for maintaining a healthy lifestyle. For more information on taking up a healthier lifestyle, please read: Health promotion.
Am I at higher risk of being overweight or obese?
Anyone, including people who have never had cancer treatment, may become overweight or obese. However, there are some medical conditions and treatments that may increase the risk of becoming overweight or obese later in life.
The following medical condition can increase the risk of becoming overweight or obese:
- A tumour near or within the hypothalamic-pituitary (HP) axis. Damage to the HP axis can increase the risk of becoming overweight and obese.
The following treatments can increase the risk of becoming overweight and obesity:
- Radiotherapy to the HP axis or an area including the HP axis
- Surgery involving the HP axis
You can find out if you had any of these medical conditions or treatments by looking at your treatment summary. If you do not have a treatment summary or if you have any questions, do contact your treating hospital.
If you are overweight or obese, it does not always mean that this is caused by cancer or its treatment. Being overweight or obese is very common in modern western society. Being overweight or obese may have other causes such as a sedentary lifestyle and unhealthy diet. It can also be secondary to endocrinological, familial, congenital conditions and several drugs (e.g. steroids, antidepressants).
Damage to the HP axis can increase the risk of overweight and obesity
Radiotherapy
Your treatment summary can tell you which areas of your body were irradiated. If you do not have a treatment summary or if you don’t understand what is written about the radiotherapy you received, do contact your treating hospital.
Radiotherapy is a treatment for cancer which uses high-energy radiation to destroy cancer cells and to shrink tumours. The radiation comes from a machine outside the body (external beam radiotherapy) or occasionally from radioactive material that is placed in the body near cancer cells (intracavitary or interstitial radiotherapy). The aim of radiotherapy is to treat only one area of the body, around and near the cancer or where the cancer was before it was removed by surgery and as far as possible to protect unaffected areas. For example, if you have cancer in your lung, you will have radiation only to your chest, not to your whole body.
External beam radiotherapy is painless and takes only a few minutes. It is given once or occasionally twice a day often for several weeks. A radiation beam is like an invisible light beam. The machines which produce the radiation beam can be moved so that the beam enters the body from different directions, ‘spotlighting’ on the area to be treated. This means that the tumour is given a high dose whilst normal areas get either a lower or no dose at all.
Since the early 1980’s computers and other technical advances have improved radiotherapy. Before this there were not many ways to protect normal tissues which were in the path of a radiation beam. Even now, whilst modern techniques allow doctors to target the cancer cells more precisely than older techniques, healthy cells may still get damaged. This can result in some of the late effects covered in the PLAIN summaries. It will help you and your follow up specialist to know what long term effects there might be after your radiotherapy if you and they have your treatment summary.
Your treatment summary can tell you which areas of your body were irradiated. If you do not have a treatment summary or if you don’t understand what is written about the radiotherapy you received, please contact your treating hospital.
I am at higher risk of being overweight or obese. What tests should I have and when?
If you are at higher risk of becoming overweight and obese, it is advised to:
What happens if I am overweight or obese?
If you are overweight or obese, your general practitioner or follow-up care specialist will probably refer you to a specialist. Depending on the cause of overweight or obesity, you may be referred to a:
- Dietician (specialist who advise on eating habits and lifestyle)
- Endocrinologist (physician who specialises in hormones and metabolism)
The specialist may discuss different options with you such as improving your diet and lifestyle.
You may also be advised to have your blood pressure, blood glucose (sugar), blood lipids (eg. cholesterol: a fatty substance in the blood) measured regularly. When you are overweight or obese, it is important to be aware of other factors that may influence your risk of (future) problems with the heart or blood vessels. For more information on high blood pressure, diabetes or dyslipidaemia (abnormal blood lipid levels) please read: Hypertension, Impaired glucose metabolism and diabetes and Dyslipidaemia.
Hormone
What else can I do?
Knowing that you may be at increased risk of being overweight and obese can be difficult. Talking to friends and family can be helpful as well as specialist counselling and/or contact with support groups, such as patient organisations. For more information on taking care of your mental health, please read: Mental health problems.
To lower your risk of overweight and obesity, adopting or maintaining a healthy lifestyle is extremely important. In particular, it is important to limit the intake of fatty foods. Taking care of your mental health may be beneficial; even small changes to your lifestyle can have a positive impact on both your physical and mental health. For more information on taking up a healthier lifestyle, please read: Health promotion.
It is also important that you monitor your weight regularly at home.
It is important that you are aware of the possibility of becoming overweight or obese and that you know the symptoms and signs. If you have any further questions or if the information in this brochure worries you, please contact your general practitioner or follow-up care specialist.
Where can I find more information?
You may find more information about overweight and obesity online. However, it is important to be aware that this information is not always up to date or accurate.
Some sources of further information are:
- NHS: Here you can calculate your BMI
- Centers for Disease Control and Prevention (CDC): Here you can find more information about being overweight and obese in general and specific to the USA
- World health organisation (WHO): Here you can find more information about being overweight and obesity in general and about ways to reduce overweight and obesity
On this website, you can also find more information related to this topic:
Please note
This PLAIN summary is based on the PanCareFollowUp guideline about “Overweight and obesity” [1], which is based on the consensus of different national guidelines.
While the PanCare PLAIN information group strives to provide accurate and complete information that is up-to-date as of the date of publication, you can check with your general practitioner or follow-up care specialist if this summary reflects the most up-to-date information available and whether it is relevant for you.
Please do not rely solely on this information. It is best to also seek the advice of a qualified medical practitioner if you have questions regarding a specific medical condition, disease, diagnosis or symptom.
No warranty or representation, expressed or implied, is made concerning the accuracy, reliability, completeness, relevance, or timeliness of this information. PanCare has produced the English version and PanCare is not responsible for the translated versions of this summary.
The PanCare materials are free to use for anyone aiming to inform about late effects and long-term survivorship care. However, no financial advantage may be achieved. All communication should reference PanCare and link to the PanCare website.
[1] van Kalsbeek, R. et al. (2021) European PANCAREFOLLOWUP recommendations for surveillance of late effects of childhood, adolescent, and Young Adult Cancer, European journal of cancer. Available at: https://www.ejcancer.com/article/S0959-8049(21)00368-3/fulltext.