This what I've learned from my Neurophysiology class. This is a very simplistic explanation for some very complex processes.
If you've had a lot stress, depression, or anxiety it can result in you gaining a lot weight. For a lot of people stress leads to stress eating and usually those are carbs because carbs are needed to help tryptophan get into your brain. Tryptophan breaks down into 5-HTP which then increases serotonin levels which help regulate mood. But carbs also tend to come with a lot of calories.I read that and thought, huh... let me look up some more. And then I found TONS of stuff. I found this on webmd: http://www.webmd.com/depression/features/craving-carbs. Hmmm...
And then this abstract: http://www.ncbi.nlm.nih.gov/pubmed/8697046 and then this: http://www.livestrong.com/article/458140-do-carbohydrates-raise-serotonin-dopamine/ and even more articles.
What I finally concluded about myself recently, that I'm using carbs as medication is spot on with this research and findings. Below is some of my life history and when I've gained weight.
I gain weight or fall off the dieting wagon EVERY winter of 8 winters I've tried to lose weight save two and ONE of those times it was only partially successful as I did go off plan and go carb crazy for a month and gained 20 pounds in that month! At that point, I was kin to Cookie Monster for real!
I have gained weight EVERY SINGLE TIME I have started a new job -without exception: 1995, 1997, 1999, 2001, 2014. Why? probably stress of new job and adapting to new habits with life that naturally follows a new job - especially if it involves a move (many of them) and in this last case, going from part-time working, mostly stay at home mom, to a full time working mom. I use carbs to boost my seratonin levels then too.
I also KNOW I depend on carbs, as I have done it in the past, when I had super late nights at work. My go to for a while at work past midnight was a can of Mountain Dew and a Snickers bar. That would keep me going for a couple more hours. Caffeine and carbs!
So, here I am on a low carb diet which is good for my blood sugar, good for my cholesterol levels, and good for more overall feeling of good health as I am terribly carb sensitive, BUT it lowers my seratonin levels which then creates carb cravings - especially in the darker months of the year. I actually DON'T eat super low carb, just much lower than the average person. Add in Seasonal Affect Disorder (SAD) and I am truly depressed in winter and I crave carbs - lots of carbs and then I start eating them and then I'm out of control. So, SAD already makes me depressed, but throw in the low carb diet and I'm making that even worse! I need to figure that out to break that cycle!
There are a couple things I could do - I could go on a higher carb diet, but I have done that before with Weight Watchers years ago and still got derailed come winter. I remember making tons of apple crisp in the late fall and then completely giving up as I got so tired that exercising in the mornings became torture, and then that stalled the weight loss and then I went crazy on carb heavy foods by January. After that incident, I gave up trying to control my weight for over a decade - it was that demoralizing and I felt so self-defeated as I didn't understand how I was doing so well and then totally derailed and ended up heavier than when I started (which also included a job change).
Now, I could try to up my carb intake with healthier carbs in winter with more fruit (apples) and healthy grains, but I think I need to accept and realize that I need an antidepressant to get me through the dark months. Once mid April hits, I'm usually OK and good to go until October. AND, I need to be faithful about using my SAD therapy light in the mornings.
So, a 3 pronged approach? Slow weight loss and increase calories by upping slower burning carbs in winter, take an antidepressant and use the SAD light. If that combo doesn't work, I'm out of ideas and honestly, that might make me feel hopeless! Oh, and add in (keep) exercise as that too is a mood lifter - so a four prong approach.
But seriously, how did I not ever notice or take note of carbs and depression before when it's so obvious for me that when I'm depressed I crave and give into carbs in a HUGE way?