In the first of the experiment series, graduate students Zahra Bahrami-Nejad and Michael Zhao, the study's co-lead authors, exposed precursor fat cells to the stress hormone glucocorticoid, which is also linked to obesity.
The researchers carefully timed the administration of glucocorticoids for four days. They alternately bathed cells grown in a petri dish in fluids with and without glucocorticoids and ensured that the total exposure to the hormone was the same. They counted how many of the precursor cells transformed into fat cells. They discovered that one pulse of glucocorticoids which lasted 48 hours made most of the cells differentiate, while shorter pulses with at least 12 hours between them had minimal differentiation.
The scientists used single-cell live imaging to check levels of PPAR-gamma protein, which is related to fat cells.
Finally, the researchers studied whether the circadian code applied to animals. Their 21-day mice study found that disrupting the normal circadian rhythm for glucocorticoids doubled their fat mass. Postdoctoral scholars and study co-authors Stefan Tholen, Ph.D., and Devon Hunerdosse, Ph.D. raised glucocorticoid levels by giving mice pellets that had glucocorticoids. They compared the mice's weight with those who lacked the said hormone. The mice which took glucocorticoids doubled their weight due to the creation of new fat cells and the growth of existing ones.
The researchers observed that the mice did not gain weight as long as they got their glucocorticoid injections during normal peak times in their circadian rhythm.
The study can help people under stress control their weight. Teruel explained that these people won't gain weight as long as the stress or glucocorticoid treatment occurs during the day. But chronic stress and glucocorticoid intake at night can lead to weight gain.
Body rhythm
The rise and fall of a healthy person’s glucocorticoid level follows a 24-hour hormone cycle. Glucocorticoid levels are at their peak at around 8 a.m., serving as a wake-up call that gets us going for the day and ramping up our appetite. Glucocorticoids — which help produce fat cells to replace damaged ones and maintain healthy fat tissue — are at their lowest at around 3 a.m. They rise again around five hours after. This means that our body is naturally wired for a certain amount of stress during the day. This tapers off at night and reaches its lowest point during the early morning hours.
This also explains why morning stress doesn't lead to weight gain while experiencing it at night can make us fatter. (Related: Stress reducing eating habits-How to eat mindfully?)
You can't avoid stress. But you can control when you have to deal with it. So when someone suggests that you sleep over a problem, follow this well-meaning piece of advice: You may just come up with great solutions the morning after when your body is ready to deal with stress, without making you gain those unsightly fats around your waist and elsewhere in your body.
Want to learn more ways on how to deal with anxiety and stress? Check out Mind.news today.
Sources include:
Please contact us for more information.
