Cancer is a group of complex diseases that can have many causes, from genetics to exposure to toxins. A person’s diet may also play a role in whether they develop certain types of cancer.

Researchers state that roughly 20% of all cancers in the United States have links to excess weight, physical inactivity, poor nutrition, or excessive alcohol consumption.

In this article, learn about the links between diet and cancer, as well as what to eat for cancer prevention and recovery.

Foods that may raise cancer risk

A man not eating a good diet for cancer

Studies so far have found it hard to find a direct link between a person’s diet and cancer risks.

Studies have not proven that there is a solid link between a specific diet and whether it may increase or decrease a person’s chance of getting cancer.

It can be challenging to find direct links between cancer risk and certain foods because people eat a wide range of foods and cook and prepare them in a variety of ways.

Some research, however, suggests that eating certain foods could change a person’s cancer risk. These foods include:

Processed foods

A 2018 study of more than 100,000 people concluded that there was a link between consuming ultra-processed foods and a significant increase — more than 10% — of developing some types of cancer.

The authors looked at the consumption of highly processed foods, including:

  • packaged breads and buns
  • packaged sweet or salty snacks
  • sodas
  • sugary drinks
  • processed meat products, such as packaged meatballs or hot dogs
  • instant soups
  • ready meals
  • food products made mostly from sugar, oils, and fats
  • food products with hydrogenated oils, modified starches, and protein isolates

Red meat and processed meat

Some meats may increase a person’s risk of getting cancer.

The authors of a meta-analysis of several studies suggested that regular consumption of processed meat could cause a higher risk of bladder cancer. The authors did not find a link between nonprocessed red meat consumption and bladder cancer.

According to the American Institute for Cancer Research, regularly eating any amount of processed meat increases the risk of stomach cancer and colorectal cancer.

Processed meats include:

  • sliced turkey
  • bologna
  • bacon
  • ham
  • hot dogs
  • other deli meats

Other research has found that consuming more than 18 ounces, or three portions, of red meat per week, increases a person’s risk of developing colorectal cancer, or cancer that affects the colon or rectum.


There is strong evidence that drinking alcohol can increase a person’s risk of cancer in certain areas of the body, including:

  • mouth
  • pharynx (throat)
  • larynx (voice box)
  • liver
  • esophagus
  • breast
  • colorectum

Although experts do not know precisely why alcohol increases the risk of cancer, it could be due to chemicals in alcohol that damage DNA or weaken the body’s ability to process and absorb nutrients.

The American Institute for Cancer Research (AICR) state that alcohol consumption may be even more harmful if a person also smokes cigarettes. They recommend not drinking at all or having no more than two drinks per day for men and one drink per day for women.

Does being overweight affect cancer risk?

person stepping on weighing scales

Being a healthy weight may reduce the risk of certain types of cancer.

More than two-thirds of adults in the U.S. are overweight or obese, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

Being overweight or obese increases the risk of health problems, such as type 2 diabetes and heart disease, and it may also increase the risk of some cancer.

Experts believe excess weight may cause certain cancers for the following reasons:

  • Being overweight can raise insulin levels and insulin growth factor-1 (IGF-1).
  • Obesity can lead to chronic inflammation in the body.
  • Higher amounts of body fat increase estrogen levels in cells.
  • Fat cells may change body processes that have links to cancer growth.

People who are overweight or have obesity may have a higher risk of these types of cancer:

  • breast
  • colorectal
  • endometrial
  • esophageal
  • gallbladder
  • kidney
  • pancreatic
  • prostate
  • cervix
  • ovary

A doctor can help a person determine a healthy weight for them and how to lose weight if necessary. An assessment may start with a body mass index (BMI) calculation and waist measurements.