Mmm, your post sounded like you were younger. I agree that you should find a way to communicate to your W how you feel. Try and get her into counselling (maybe to deal with her grief over her father and sister). In counselling, she will be in a safe place for you to broach this subject. Also, you'd want her to deal with any issues before baby is born. Be sure to let her know that you are concerned for her, and want only the best for her. It does sound like she is depressed, and I don't think it's a case of letting herself go after finding a H (although, I could be wrong, but women rarely do this on a conscious level, that I know of). I think everything seemed to happen around the time of the wedding, and maybe it was just too overwhelming for her, and she finds comfort in food. Many people do. Then being overweight makes them feel bad about themselves and the next thing to go is the make-up, and hair. It's a loop that many people can't get out of, so please be there for her, and make sure she knows you love her.
Okay, the delicate subject of farting and burping ... oy! Anyway, often a pregnancy can add to this, not the food one is eating. Of course, we women do fart and burp just like men do, the difference is that we don't normally allow ourselves to do so unless we feel really comfortable in the R ... at least, not me (I have been married for almost 22 years, and except for the odd accident, have only been doing this in front of my H in the last 8 or so years). It's just a bodily function, and unless your W's is completely abnormal (in which case, seeing a doctor, or getting those anti-gas pills might help), I think you need to find a way to live with it, because even if you end up with someone else, they too will be letting off steam, as it were, eventually.
Try and set the example for your W without making her feel like you are judging her. Have you tried encouraging her to eat healthier for the sake of the baby? Maybe, volunteer to do the grocery shopping and cooking for awhile, and make sure you both eat only healthy stuff. This might set a trend, that will also be established when baby arrives ... you want to bring up your child with healthy eating habits, after all, so maybe you can discuss that angle with her. Encourage long, romantic walks, for your dates (I assume you still do go on dates), or go bowling, or other activities where you aren't just sitting around and eating.
There is always hope when we are willing to make the effort, IMHO. I hope you are able to figure it out. All we can do here is give you our thoughts, and impressions, from our own perspectives, from our own experiences, so hope you can glean some nugget of info that will help you.
Take care.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim