Our eating habits change whenever we are stressed. It's long been suspected that stress can lead to weight gain, but a new study - the first of its kind - now suggests that long term stress can lead to gaining weight over time.
Researchers from University College London (UCL) conducted the study on 2,527 men and women over the age of 50. They measured the level of cortisol, the stress hormone, in two centimetre clippings of hair (about two months' growth).
‘It's not actually clear whether stress causes obesity - being overweight could also be a source of stress for some people.’
After taking into account variations in age and sex as well as other factors like whether someone smokes or has diabetes, the researchers found that the higher the level of cortisol (ie. the more stressed someone was), the bigger the body weight, BMI and waist circumference of the person.
What's more, having a higher level of cortisol was also linked to persistent obesity over time. Previous studies that have looked into the connection between stress and weight-gain have always studied cortisol levels in the blood, urine or saliva, which vary throughout the day and are affected by temporary factors.
This research is the first that's ever found a way to measure stress levels over the course of two months. However it's not actually clear whether stress causes obesity - being overweight could also be a source of stress for some people.
Lead study author Sarah E. Jackson, an epidemiologist at UCL, said that while we probably can't eliminate all stress from our lives, we might be able to find ways to control it: "Even just being aware that stress might make you eat more may help." So if you want to lose weight, perhaps it's time to stop counting calories and simply relax.