Hello!
While I am not your target audience and cannot speak from experience, I thought what little knowledge I had of “hunger” could maybe be of some help. However, I would like to emphasize first of all that you are not a failure and should not place any shame in weight gain. I also would like to say I am glad you have a supportive team on your side and reaching out to people who can relate. It shows you are taking an active role and you should recognize the goals you have met and your journey so far. It’s easy to focus on everything that didn’t go according to plan, but such an approach devalues all your effort so far, which is unfair to you.
The next thing I would like to address is your word of choice. You said “appetite” and we can understand “appetite” as hunger, though they are not exactly the same thing.
“Hunger” is a physical cue designed to make us seek food, but cravings produce almost the exact same sensation. In my case, the hardest part of my journey so far has been the preop diet, where I felt both hungry and anxious to eat. My body’s reaction to stimuli made me realize some things: when I have not eaten, I get hungry. When I have eaten too little, I get hungry. When I am idle and become bored, I get hungry. When I am sad, I get hungry. When work has been stressful, I get hungry. When I see something that looks tasty, I get hungry. When I see my family eat, I get hungry. When I am watching TV, I remember popcorn and I get hungry. When I am anxious, I get hungry. When I am walking with my dogs, I see a bistro I used to frequent and I get hungry. Sometimes, I get hungry when I have just eaten and cannot realistically eat anything. As it was, I had to ask myself what was hunger and what felt like hunger. The sensation was almost identical. I didn’t really experience hunger before surgery. I could eat once a day and sometimes not even that. I could eat a lot and then nothing at all for several hours. I could eat without realizing I was, in fact, eating (specially when bored). When I had to restrict my eating patterns, I felt actually hungry for the first time in a long time. I could also see I craved things I didn’t before, because now they were out of bounds. It was maddening. It also gave clarity to things I could not see before. So I had food addiction and used food as a coping mechanism. Of course I knew that, but could not actually believe it until I saw it in action.
To be fair, cravings and hunger are very alike. I have become to understand cravings as an emotional hunger, a need I am trying to repress and makes itself known in another way. I know it is not hunger, but it feels just the same. Awareness of how my head works has enabled ways to work around it. Surgery has been immensely helpful in physical restrictions that allow me to address the mental aspect of my eating habits. It is also difficult and sometimes even sad. For me, that is the mental facet of hunger.
There are, however, physical aspects of hunger that are invisible, but for their obvious effect. Hunger can be hormonal (bariatric surgery takes out a good portion of the stomach, including the place where most of the ghrelin is produced, which translates in very little huger for some patients). Fluctuations in blood sugar can trigger hunger cues. Inflammation in the digestive tract can feel like a hollow place, which our brain translates as hunger. Depression causes chemical imbalance in the brain that can make you feel hungry. So does anxiety. That’s why some antidepressants can cause weight gain or weight loss. Psychiatrist are unable to say why, though some theories have been proposed. The stomach has the highest concentration of neuro transmitters, so gut microbiota influences hunger too. The food we eat influences micro biota in turn. Artificial sweeteners affect metabolism and hunger. So does sugar. There are many other factors. As you can see, actual physical hunger has so many correlations, they are very hard to pinpoint. I don’t think hunger as a mechanism is all that well understood. There is a video by John Pilcher, a bariatric surgeon, where he explains it much better than I could. There are many studies about it, but they make for dry reading material (Google Scholar can help you find some, if you are inclined to consult them). Understanding hunger is very difficult, but our reaction to hunger can be trained. It will force you into a fight with yourself every day, and sometimes you will lose that fight out of sheer exhaustion. Battling ingrained impulses is a lifetime of work. Sometimes you will not feel like resisting it. That’s completely okay. Every day is a choice, and every day you can chose how to act. It’s okay to need help. It’s okay to need more help after that. Some people need revision surgery, and that is fine. Some people can lose weight (a lot of it too) without surgery. I was not one of them and felt very ashamed of it for a long time. I thought I was weak willed. I thought I needed to try harder. I was wrong. I needed help, got help and I am doing much better. If I ever need more help, I hope I can be strong enough to ask for it. Kind enough to accept I need it and allow myself to receive it. You are not failing at anything. You just need more guidance and another crutch. It’s okay. Please don’t be ashamed. Please don’t be so hard on yourself. Look after your mental health. Look after your physical health. You deserve to be happy. You deserve to be comfortable in your body. You deserve to be healthy.
I wish you all the luck!