The FastDay Forum

Hi all you knowledgeable people out there!

I've been trying to find out a bit about how 5:2 and other forms of IF stress the body, or how it impacts on existing stressors. I've done a quick search on this and on IF and cortisol levels, but I'm not finding much. I'm sure I've read some comments in the forums talking about stress & cortisol levels, so I'd be interested if anyone's able to point me in the direction of any good studies out there.

Thanks!

Just to add - I did find this thread in the forum...and it's about all I've been able to find so far.

I've just come across this very interesting paper about leptin (a hormone that controls appetite: low leptin stimulates appetite). It's not that recent a study but I believe it offers a bit of an insight into what may be happening for some people.

http://www.ncbi.nlm.nih.gov/pubmed/9274707


TL:DR
Fasting for 20 hours caused a drop in leptin in the last 4 hours of the fast which was greater in lean than overweight people. Leptin levels are lower when cortisol is raised.

This implies that fasting for more than 16 hours may increase appetite in lean individuals (perhaps linked to the set point idea in that the body tries to prevent weight loss when you get slim). It also implies that stress, which increases cortisol will also cause increased appetite.

I think this study provides a mechanism for the famine reaction and how it's possible to fast too much and how stress interferes with weight loss.

[carorees]

I've written about stress and fasting in the troubleshooting section of the main site:
https://www.fastday.com/fasting/should- ... essed-out/
Which may give you a bit more information.

Interesting article. I find it very timely as I had started fasting again, but lots of stresses in my life put it way down the priority list. I rapidly gained 5 kilos over about 6 weeks (eek). I was aware of the connection between cortisol, stress and weight gain, but really didn't understand exactly how much of an impact there could be. I am back on the forum today trying to decide whether to go back to fasting and after reading that, have decided to wait a little while until everything is back to normal.

Wow - great timing! Thanks Carorees - I've been reading those facts and troubleshooting entries with great admiration, but hadn't come across that one yet. It does confirm a lot of what I'd already suspected.

Stress in my work has been building to a real climax recently, and I've been wondering whether fasting has been increasing my stress levels or not. As it is, I've dropped from my normal 6+ cups of daily coffee to one or often none! as I no longer seem to have a tolerance for caffeine. But I've not really been feeling hungry, which I had thought went along with increased cortisol. If anything, I've been feeling that fasting has been helping with how stressed I've been, which I hadn't expected...hence the question. I really appreciate the thoughts contained in those sentence: "Intermittent fasting may counteract some of the effects of raised cortisol due to its beneficial effects on blood sugar, carbohydrate metabolism and mood."

Time for me to read those references in your article. Thanks for giving me some food for thought!