Having a healthy body weight is linked to lower risk of many types of cancer, fewer or less severe side effects and symptoms, and in some cases better survival after diagnosis. Body weight is also an important body terrain factor—a condition that influences whether your body is more supportive or less supportive of cancer.
Healthy body weight at a glance
Having a healthy body weight is linked to lower risk of many types of cancer—at least 13 cancer types have known links to obesity. Obesity is linked to other body terrainthe internal conditions of your body, including nutritional status, fitness, blood sugar balance, hormone balance, inflammation, and more factors that are known to support cancer development and growth, including high blood sugar and insulin resistance, hormone imbalances, immune function, inflammation, oxidative stress, and microbiome imbalances. A healthy body weight is linked to fewer or less severe side effects and symptoms, and in some cases better survival after diagnosis.
Whether your goal is to lose weight or gain it, we offer strategies and resources that can help. These are based on keeping your focus on your health and wellness.
Some self-care practices and complementary therapies can help you manage your body weight. These have the best evidence of effectiveness:
What’s a healthy body weight for you?
To measure whether or not body weight may be a concern for you, measuring your Body Mass Index can be a useful tool. Body mass index (BMI) compares your weight to your height; it is calculated as kilograms per meter squared (kg/m²). Most of the research we cite defines overweight as a BMI between 25 and 29.9, and obesity as a BMI of 30 or higher. Underweight is a BMI lower than 18.5. Like the researchers we cite, we realize that BMI is not a perfect measure of overweight or obesity, as it doesn’t differentiate between lean body mass and excess body fat. But a BMI between 18.5 and 24.9 is a good indicator of healthy body weight for most people.
What can contribute to gain or loss of body weight?
Medical conditions
Underlying medical conditions or imbalances may lead to an unhealthy body weight. Consider addressing these factors with a trained practitioner, such as an integrative or naturopathic physician. See Finding Integrative Oncologists and Other Professionals ›
Insulin resistance1Malone JI, Hansen BC. Does obesity cause type 2 diabetes mellitus (T2DM)? Or is it the opposite? Pediatric Diabetes. 2019 Feb;20(1):5-9.
Low vitamin D levels2Xu J, Yuan X et al. Association of circulating 25-hydroxyvitamin D levels with colorectal cancer: an updated meta-analysis. Journal of Nutritional Science and Vitaminology (Tokyo). 2018;64(6):432-444.
Hormone imbalances
Imbalances in your microbiome
Cancer treatments
In some cases, weight loss or gain may be a direct result of your cancer treatments. Consider speaking with your healthcare team on strategies to support you. Focusing on your health and wellness through the 7 Healing Practices and addressing body terrainthe internal conditions of your body, including nutritional status, fitness, blood sugar balance, hormone balance, inflammation, and more factors may support your health and wellbeing even as you are experiencing weight loss or gain as a side effect of cancer treatment.
- Chemotherapy may cause problems with eating and digestion leading to unintended weight loss.3Nutrition in Cancer Care (PDQ®)–Patient Version. National Cancer Institute. May 24, 2022. Viewed September 17, 2022.
- Hormone therapy may lead to unintended weight gain.4Nutrition in Cancer Care (PDQ®)–Patient Version. National Cancer Institute. May 24, 2022. Viewed September 17, 2022.
- Steroids and cranial radiation are linked to obesity.5Esbenshade AJ, Simmons JH, Koyama T, Lindell RB, Friedman DL. Obesity and insulin resistance in pediatric acute lymphoblastic leukemia worsens during maintenance therapy. Pediatric Blood & Cancer. 2013 Aug;60(8):1287-91.
Other medications
Some prescription medications can lead to unintended weight gain. “Common drugs that cause unwanted pounds include corticosteroids, antidepressants, diabetes medications such as insulin or those containing sulfonylureas, some heartburn drugs, hormone therapy/contraceptives, and anti-seizure drugs such as Depakote®.”6Prescription Medications & Weight Gain. Obesity Action Coalition. Viewed January 19, 2023.
Weight gain is listed as a rare side effect of nonsteroidal anti-inflammatory drugs.7Ogbru A, Marks JW. COX-2 Inhibitor Medications. Rx List. Viewed February 8, 2021; Pantziarka P, Sukhatme V, Bouche G, Meheus L, Sukhatme VP. Repurposing Drugs in Oncology (ReDO)-diclofenac as an anti-cancer agent. Ecancermedicalscience. 2016;10:610.
Making changes
We encourage you to keep your focus on your health and wellness, whether you’re trying to lose or gain weight. Our 7 Healing Practices, including Eating Well and Moving More can support you in achieving a healthy weight as part of overall health..
If you would like support in practices to promote a healthy weight and overall health, see our recommendations for making changes in each of these handbooks:
Losing weight
Weight loss interventions from hospitals or other groups involving advice and support on eating and physical activity often lead to weight loss.8Shaikh H, Bradhurst P et al. Body weight management in overweight and obese breast cancer survivors. Cochrane Database of Systematic Reviews. 2020 Dec 11;12(12):CD012110. If you think this could help you, ask your doctor to refer you to a local or online program.
Resources for losing weight
Gaining or maintaining weight
If gaining weight or preventing weight loss is the issue you’re facing, you’ll find advice from these resources:
Resources specific to gaining or maintaining weight during or after cancer treatment:
Continue exploring
References