Health knowledge and news provided by doctors.

Exposure to light may help you shed pounds

Harold Mandel's picture

Go out and enjoy some sunshine as it may truly be a good way to lose weight. Improve your diet in a healthier and more natural way.


A novel natural manner to help you maintain a healthy weight is to expose yourself to an adequate amount of light early in the day. In view of the obesity epidemic and the literal frenzy to find safe and effective manners to avoid being overweight, this is significant news. Aside from eating healthy low calorie food and getting a good amount of exercise daily, it's time to also consider making light a part of your daily prescription for weight control.

The timing and intensity of light have been found to correlate with body weight in adults, reports the journal PLOS ONE. Researchers have found that exposure to light can influence sleep and circadian timing, and each of these have been shown to have an influence on the regulation of weight. Researchers pursued a study of the relationship which exists between ambient light, sleep and body mass index. It was concluded that exposure to moderate levels of light at biologically appropriate times can have an effect on weight which is independent of sleep timing and duration.

Interestingly, it has been observed that people who are exposed to earlier sunlight are thinner than people who get afternoon light, reports Northwestern University in a review of this research. This study is the first time it has been shown that the timing, intensity and duration of your exposure to light during the day is associated with your weight.

Follow eMaxHealth on YouTube, Twitter and Facebook.
Please, click to subscribe to our Youtube Channel to be notified about upcoming health and food tips.

The researchers found that people who were exposed to even moderately bright light primarily in the morning had a significantly lower body mass index (BMI) than people who were exposed to light primarily later in the day. Co-lead author Kathryn Reid, a research associate professor of neurology at Northwestern University Feinberg School of Medicine, has said, “The earlier this light exposure occurred during the day, the lower individuals’ body mass index.” Reid has also said, “The later the hour of moderately bright light exposure, the higher a person’s BMI.”

Study senior author Phyllis C. Zee, M.D., a professor of neurology Northwestern University Feinberg School of Medicine, has pointed out that light is the most potent agent to synchronize your internal body clock which regulates circadian rhythms, and this in turn also regulates energy balance. Zee suggests that you should get more bright light between 8 a.m. and noon. BMI can be affected by as little as 20 to 30 minutes of morning light. Zee says without sufficient light at the appropriate time of day your internal body clock could be de-synchronized, which can lead to an alteration of metabolism and can lead to weight gain.

Zee has said that many people in the United States do not get enough natural light in the morning because most of the American lifestyle is indoors. People also often work in poorly lit environments. An average working environment is only about 200 to 300 lux. In this study the magic number, or the minimum threshold for maintaining a lower BMI, was 500 lux. Outdoor lighting is generally a lot better. Outdoor light is greater than 1,000 lux of brightness even on a cloudy day.

Reid sees light as being a modifiable factor which has the potential to be used in weight management programs. Manipulating light to help lose weight becomes as real a consideration as manipulating sleep and diet. Santostasi, a physicist, has said what he saw was how much light you receive is not the only factor which is most associated with body mass index. It is also important to consider when you are exposed to light and for how long.

I have observed a growing obsession among many people with weight control due to concerns about the growing nature of the obesity problem. Quick fix crash diets are often dangerous. However, working on maintaining a sensible low calorie but nutritious diet is certainly worthwhile. Daily exercise is also helpful. A new effective natural prescription to assist with weight control now also appears to include getting adequate daily exposure to light as early as possible in the morning.