Carrying excess body fat increases the risk of stomach cancer by 23% for every five-unit-increase in body mass index, according to the report released Thursday aby the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF). It’s also linked to other major cancers like breast cancer, colon cancer, and thyroid cancer.

“This report is a real wake-up call,” Alice Bender, head of nutrition programs at AICR, said in a statement. “We want Americans to know there are steps everyone can take for cancer prevention and better health, like eating more vegetables, beans, fruits, and other plant foods along with squeezing in a few more steps every day.”

The report analyzed 89 studies available globally on stomach cancer, diet, physical activity, and weight. It’s the first such comprehensive review of existing literature since 2007 and covered some 17.5 million adults, of whom 77,000 were diagnosed with stomach cancers.

Stomach cancer is the fifth most common cancer worldwide, though it ranks No. 15 on the most common types of cancer in the U.S. Over 26,000 Americans were diagnosed with the disease last year, and only about 30% of those patients will survive five years. AIRC estimates that about one in seven stomach cancer cases could be prevented by maintaining a healthy weight, drinking less alcohol, and avoiding processed meats.

More than a third of Americans are obese. Another third are overweight. One study using National Cancer Institute data estimated that about 34,000 new cancer cases in men and 50,500 in women were due to obesity. The types of cancers varied widely, but the risk was elevated by as much as 40% for some cancers like endometrial cancer and esophageal adenocarcinoma.

The exact reasons obesity causes cancer are varied and no one link has been determined. Though, there are several possible mechanisms driven by the specific actions of fat cells, like increased levels of estrogen, insulin, and other hormones.

The burden of obesity-linked cancers is expected to grow exponentially, leading to about half a million new cancer diagnoses in the U.S. by 2030, the NIC estimated. The group’s analysis found that this could be avoided if every adult reduced his or her body mass index by 1%. In fact, this could potentially prevent about 100,000 new cancer cases by 2030.