Thought provoking study suggests that having a bedroom that isn’t completely dark such as sleeping with the TV on may be linked to weight gain and insulin resistance. Simple remedy that may be effective in helping with maintaining a healthy weight is to remove the TV from the bedroom! Light-dark cycles are known to be associated with melatonin release and this in turn is associated with tryptophan uptake in the brain. Tryptophan is an unusual amino acid and is taken up by the brain most rapidly when other amino acids circulate at lower levels such as after a carbohydrate only meal – maybe its not just the TV light but maybe that triggers cravings for soda and chips too. This study looked at mice (admittedly not humans but easier to control!) and found that exposure to a relatively dim light at night over 8 weeks caused a 50% greater weight gain than in mice who had a standard light-dark cycle.
French researcher J Le Magnen back in the 1980’s described fat building (lipogenesis) in association with dark cycles of rats contrasted to fat burning (lipolysis) during the light cycle. His findings were controversial at the time but maybe we should look again at how obesity may be not just about what we eat but how well we sleep.
“Neurobiology of feeding and nutrition” by Jacques Le Magnen
Academic Press, 1992