You should rule out any medical cause, such as hypothyroidism, which is pretty common and messes with your metabolism.
Keeping to reasonable portion sizes and saying no to work food (especially when you aren’t hungry) is something to figure out and it indicates possibly that you are feeding something other than your body, like worries or nervousness about things.
Alternatively, you could be medicating your body with food. That’s what I used to do. I did a poor job of managing my hypothyroidism, which made me feel awful, and I used food to feel better chemically.
Regarding exercise, my advice is to only make the smallest, least painful change. (Like-driving-past-the-gym-every-day small.) Work only on that until you can sustain it and only then move on to something more challenging. Before you know it, you will have good momentum with no worries at all about failing.
Can you envision yourself smaller? I realized during my weight loss process that at the beginning it was difficult to imagine what that would mean. I had been a big guy for so long that it seemed normal.
I would also say to avoid wheat and sugar. First, sugar begets sugar. Second, wheat may mess with you. I’ve been off it long enough to notice a difference when I do indulge. My abdomen gets bloated or swollen, and my whole GI situation is noticeably less pleasant. I don’t know much about the whole gluten controversy, but I know the difference in my body.
Last, I would encourage you to start seeking the solution in earnest from a spiritual or heart-centered place. Like you said, you have all the information. Thinking more or harder or better is probably not going to solve the problem. My money is on a spiritual or heart-centered solution. Pray or meditate or do whatever feels spiritual and heart-centered to you to trade your frustration with some guidance, wisdom or even magic. It can work.
I lost 30 lbs from this past July to Nov, and I’ve kept it off. What started it all for me was deciding to work my way up to 100 pushups. So at 248 lbs, that’s all I bothered to do for 10 weeks.
Somewhere along the way, I started praying for better dreams before I fell asleep. Instead of having anxious dreams like I used to, I had the same dreams but was not an anxious person in them.
In May and June last year, I came upon a meditation practice. As I grew into it, a lot of worries and chunks of my life that were a struggle just fell away.
I started to pay attention to my thoughts about eating, and I notice that I had multiple thoughts per hour about having something to eat when I wasn’t really hungry. So for a while, I had this conversation: “I should eat something. No, I’m not hungry.” This happened for weeks and throughout the day but eventually abated.
I also realized that I wasn’t going to starve. That allowed me to try eating only enough to get to the next meal. If I got hungry in between, I’d eat just enough. I found that to be a really good practice.
Eventually, too, my appetite and my hunger changed. I went from having rabid hunger that demanded a binge to a pleasant gnaw that I learned I could take care of either now or an hour from now. That in itself was pretty miraculous, because it freed me from being driven by the food. My change in appetite, which I attribute to some grace, was doing the heavy lifting now instead of me.
So I went from 248 to 218, and I’ve pretty much plateaued since Nov. despite adding running a few miles most days of the week. I’ve also been more lax with my eating habits, but I’m just waiting for the next window of really clean eating to come along for some more weight loss. What absolutely amazes me is how little I really need to eat to get through the day. It’s a fraction of what I used to eat, and it can amount to pennies at the checkout.
So, it really doesn’t have to be hard if you have some patience. And it doesn’t take much patience because if you lose 5 or 10 lbs you’re going to feel loads better guaranteed. So give up on brute force and willpower and tune in to the universe (whatever that means for you—and the tuning in part is your work) and let it push you in the right direction.