Funded by Breakthrough Breast Cancer and the Institute of Cancer Research, the University of Oxford conducted a study in to the links between lighting levels and obesity.
Research has shown that in animal studies light exposure caused weight gain even though the energy intake and physical activity remained the same.
The researchers wanted to investigate whether disruption in sleep caused by too much light may be linked to obesity. The study did find a link between increasing light levels and obesity but have maintained that there is no concrete proof that light causes obesity.
The researchers thought melatonin might be playing a significant factor in this as melatonin is restricted by light and affects metabolism.
Sleeping in a darkened room is better for your health as it can help regulate sleep patterns, provide a deeper and more refreshing sleep.
The researchers said: "In this analysis of over 113,000 United Kingdom women [different measures of weight and body fat] increased with increasing lightness of the room slept in at night. These associations were still present after adjustment for age, socio-economic status, alcohol consumption, strenuous physical activity, night shift work, having a young child, sleep duration, and current smoking."
Professor Anthony Swerdlow from the Institute of Cancer Research said: "There might be other explanations for the association, but the findings are intriguing enough to warrant further scientific investigation."