Key Takeaways
- There is a strong link between body weight and the risk of developing cancer
- Eating a balanced, plant-based diet with moderate portion sizes can help maintain a healthy weight and reduce cancer risk
- Following guidelines and doing 150 minutes of physical activity each week can help reduce cancer risk
- For women, maintaining a healthy weight during and after the menopause is especially important
Cancer rates are increasing, and are the highest in developed countries that have high rates of obesity. According to the World Cancer Research Fund (WCRF), there is strong evidence that being overweight or living with obesity throughout adulthood increases the risk of at least 12 different cancers. Research also shows that 13% of cancers worldwide are attributable to obesity. The WCRF has created guidelines to help people understand how to reduce their cancer risk. The first of these is to keep your weight within a healthy range and avoid weight gain in adult life. In this article, three Perci professionals, registered dietitian Megan Pattwell, clinical exercise coach Nick Michell and lead cancer nurse specialist Rachel Rawson, share important information about cancer and body weight, and how to approach diet and activity for cancer prevention.
The role of diet in weight management and cancer prevention
Megan Pattwell, Registered Dietitian, Perci Health
While we can’t completely eliminate the risk of getting cancer, we can take sensible steps towards reducing it. Maintaining a healthy weight is an important way to do this, and that means staying active and eating a balanced diet.
Each meal should be as balanced as possible. Always include a quality lean protein (like chicken breast, mince, fish, beans or pulses), a complex starchy carbohydrate (like bread, pasta, rice or potatoes and opt for the whole grain versions if you can), and as many fruits and vegetables as you can get in. Good quality sources of dairy are important as they contain protein and important micronutrients. Plant-based alternatives are also good, as long as they are fortified.
For cancer prevention, look to limit the amount of red meat you eat, which has links with certain cancers, as well as limiting refined sugars, which are found in cakes, sweets, biscuits and soft drinks. Limit alcohol as much as possible – current guidance in the UK is 14 units per week. Food isn’t just fuel, but also important psychologically and socially, and should be enjoyed. My advice is to always eat in moderation and according to recommended portion sizes.
Food isn’t just fuel, but also important psychologically and socially, and should be enjoyed. My advice is to always eat in moderation and according to recommended portion sizes.
Megan Pattwell, Registered Dietitian, Perci Health
There are lots of claims around food and cancer that lack evidence. These can cause anxiety, and following restrictive diets can make you unwell. Instead of making drastic changes all in one go, try to focus on one or two smaller goals at a time. The focus should always be on what good things you can include in your diet, to nourish your body’s healthy cells, rather than what you can restrict.
The role of insulin regulation in weight management and cancer prevention
Nick Michell, Clinical Exercise Coach, Perci Health
An important aspect of cancer risk reduction is something called ‘insulin regulation’. Insulin is a hormone that’s released when there’s too much glucose (sugar) in the blood. Research shows that high insulin levels are linked to an increased risk of cancer. If you’re overweight and have more fat tissue, you will have higher levels of insulin and an increased cancer risk.
Regular exercise increases insulin sensitivity, which means your body will be more effective and efficient at lowering insulin levels. The more activity you do, the more you lower your body fat, your insulin levels and your cancer risk. This doesn’t have to be complicated. We should all be aiming for around 150 minutes of moderate activity a week, as well as strength sessions that activate the major muscle groups.
I always advise people to find things they really enjoy. Gardening, walking, dancing – as long as you’re physically moving your body and maintaining a healthy body weight, you’re on the right track. You don’t have to run a marathon, unless you want to of course. The key to success is consistency.
The more activity you do, the more you lower your body fat, your insulin levels and your cancer risk.
Nick Michell, Clinical Exercise Coach, Perci Health
The role of oestrogen in weight management and cancer prevention
Rachel Rawson, Lead Cancer Nurse Specialist, Perci Health
Being overweight or obese may affect the balance between the damage that happens to our DNA from outside factors, such as the environment, and how well we can deal with it. Having excess fat in our cells and tissues can act as a stress and lead to inflammation which can, over time, damage our DNA.
Fat cells make oestrogen, a female hormone that can lead to some cells dividing and replicating at a quicker rate. As fat cells are the main source of oestrogen after the menopause, the more you have, the more oestrogen you have, which in turn can lead to cancer. That means maintaining a healthy body weight after the menopause is important.
Making lifestyle changes can be challenging. Our Cancer Nurse Specialists can talk you through cancer risk factors, and side-effects associated with treatment, as well as refer you to other Perci professionals, like registered dietitians and clinical exercise specialists, who can offer support.
While we have ensured that every article is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. If you have any questions or concerns, please talk to one of our healthcare professionals or your primary healthcare team.
References:
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Courneya KS, Segal RJ, Gelmon K, Friedenreich CM et al, ‘Six month follow up of patient rated outcomes during Breast Cancer Chemotherapy’, Cancer Epidemiol Biomarker Prev, December 2007, 2007:16 (12): 2572-8
‘The Third Expert Report,’ wcrf.org, 2018, https://www.wcrf.org/diet-activity-and-cancer/global-cancer-update-programme/about-the-third-expert-report/
‘ESPEN practical guideline: Clinical Nutrition in cancer’, espen.org, 2021, https://www.espen.org/files/ESPEN-Guidelines/ESPEN-practical-guideline-clinical-nutrition-in-cancer.pdf
Nathalie Druesne-Pecollo et al., ‘Excess body weight and second primary cancer risk after breast cancer: a systematic review and meta-analysis of prospective studies,’ pubmed.ncbi.nlm.nih.gov, August 2012, https://pubmed.ncbi.nlm.nih.gov/22864804/#article-details
Todd M Gibson et al., ‘Body mass index and risk of second obesity-associated cancers after colorectal cancer: a pooled analysis of prospective cohort studies,’ pubmed.ncbi.nlm.nih.gov, September 2014, https://pubmed.ncbi.nlm.nih.gov/25267739/#article-details