Researchers tied three behaviors to higher scores on tests of mental ability in children: at least 60 minutes of physical activity a day, nine to 11 hours of sleep a night and no more than two hours a day of recreational screen time.

The study, in Lancet Child & Adolescent Health, included 4,524 children ages 8-11 who were assessed with six standard tests that measure language skills, memory, planning ability and speed at completing mental tasks.

Compared with those who met none of the three behavioral criteria, those who met all of them scored about 4 percent higher on the combined tests. Meeting the requirements for both screen time and sleep was associated with a 5.1 percent increase in scores compared with those who met neither. Only 5 percent of the children met all three criteria, and nearly 30 percent met none.

RESEARCHERS LINK OBESITY TO COLON CANCER

Obesity is linked to an increased risk for colorectal cancer in younger women, researchers said.

Colorectal cancer rates have been increasing in people under 50 while declining in older people. No one knows why.

In an observational study published in JAMA Oncology, researchers prospectively tracked the health of more than 85,000 women for 22 years, beginning when they were 25-42 years old. They found 114 cases of colorectal cancer in women under 45.

The higher a woman’s body mass index, the greater her risk for early-onset colorectal cancer. Compared with women of normal weight — a body mass index between 18.5 and 22.9 — obese women, with a BMI over 30, had a 93 percent increased risk for the disease. Weight gain from age 18 on was also associated with colorectal cancer. Compared to women who gained 10 pounds or less, those who gained 44-88 pounds had a 65 percent increased risk, and those who gained more than that had more than double the risk.