Some 84,000 cases of cancer could be prevented every year if people lost weight, exercised and cut their drinking, experts have said.
The World Cancer Research Fund (WCRF) published data showing how many cancer cases in the UK could be stopped if people led more healthy lifestyles.
It estimates around a third of cases could be prevented through improved diet, exercise, lower alcohol intake and keeping to a healthy body weight.
Around 38% of new incidences of breast cancer (20,300 cases) could be prevented every year, along with 19,800 cases of bowel cancer, 2,200 cases of kidney cancer and 1,400 cases of pancreatic cancer.
Among men, 9% of cases of advanced prostate cancer could be prevented every year if men were not overweight or obese.
In 2013 - the most recent data available - 351,578 new cases of cancer were diagnosed in the UK. This is up from almost 340,000 in 2012.
As a result, the number of cancer cases that could be prevented also rose, from around 81,000 to 84,000.
Breast cancer is the most common among women, accounting for almost one in three new cases.
In men, prostate cancer is the most common, accounting for 26%.
Rachel Thompson, World Cancer Research Fund's head of research interpretation, said: "The number of cases of cancer is increasing each year, but we mustn't stand by idly and watch - there are things we can do.
"There is no doubt that simple changes to diet and lifestyle can make a huge difference in the battle against cancer.
"Even minor adjustments, like 10 to 15 extra minutes of physical activity each day, cutting down on alcohol, or limiting your intake of high calorie foods and sugary drinks, will help decrease your cancer risk."
Dr Thompson said that after not smoking, being a healthy body weight is the most important thing people can do to cut their risk of getting cancer.
She said: "There is strong evidence that being overweight or obese increases the risk of 10 cancers."
Rachel Rawson, senior clinical nurse specialist at Breast Cancer Care, said: "This study is further proof that eating a well balanced diet, taking regular exercise and limiting alcohol intake can help reduce your risk of breast cancer.
"However, we must stress that lifestyle choices will not completely prevent the disease. The main risk factors for breast cancer remain out of our control - being female, getting older and, for some people, a significant family history of the disease."
Professor Kevin Fenton, director of health and wellbeing at Public Health England, said: "The harsh reality is that we are currently behind on cancer survival rates in comparison to our European counterparts, and a major factor is that cancer prevention is not in the public consciousness.
"The link between tobacco and cancer is widely known and readily accepted by the public but many are not yet fully convinced that healthy eating, regular exercise and not drinking alcohol can lower your cancer risk."