five years, the study found. And the level of artificial light seemed to matter, Park said.
“For example, using a small nightlight was not associated with weight gain, whereas women who slept with a light or television on were,” he explained.
The findings didn’t change when researchers accounted for women’s diet and physical activity, which suggests that light during sleep may be important in weight gain and obesity.
Dr. David Katz, director of the Yale-Griffin Prevention Research Center in New Haven, Conn., reviewed the findings. He said the link between exposure to artificial light at night and obesity may not indicate that one causes the other.
“As with any study of association, two findings are
