In U.S. women aged 20–49 between 2001 and 2018, changes in cancer rates over time were not statistically linked to overall levels of physical activity, fiber consumption, or total calories consumed at the population level.

Between 2001 and 2018, alcohol consumption rose steadily among U.S. women aged 20–49, and this increase was statistically linked to higher rates of breast, colorectal, and uterine cancers. No similar links were found with smoking, calorie intake, saturated fat, or physical activity.

Between 2001 and 2018, rates of breast, colorectal, and uterine cancers rose significantly among U.S. women aged 20 to 49, with the fastest increases occurring in women under 30, especially White women aged 20–24 for colorectal cancer and Hispanic women aged 25–29 for uterine cancer.

In U.S. women aged 20–49 between 2001 and 2018, those with severe obesity (BMI ≥ 40) had a stronger statistical link to cancer rates than those with mild obesity, suggesting that higher body weight levels correspond more closely with increased cancer occurrence.

People who are more physically active have a 10% lower risk of developing colorectal cancer compared to those who are less active, based on standardized activity measurements.

Between 2001 and 2018, the number of U.S. women aged 20–49 with obesity rose steadily each year, with the most severe form rising faster. During the same period, the rates of breast, colorectal, and uterine cancer also rose, and these increases were closely aligned in timing across the population.