worried about my dad opinions please.

I'm starting to worry about my dad. We have had a lot of loss in the family over the years. He has always been one who doesn't really show his negative emotions. In the last several months he has thrown himself into this new recent hobby of his, at the expense of everything else. It's a sports related hobby, and basically all he does is sports. He's constantly watching sports, pouring hours upon hours into this hobby, st the expense of nearly everything else, and very much abandoning his relationship with my mom. Recently it's like he's stopped caring about his health in general, and barely eats, or eats really not in a healthy way. Like he will eat a couple of cheese sticks for a meal, and then for a different meal eat an entire box of mac & cheese which is upwards of 1000 calories. Apparently last night he made dinner (he works a 9 to 5 and my mom works 12 hour shifts, getting home late, so he is the one usually with dinner falling on him) and he made a pork tenderloin, and zucchini for my mom and also made the box of mac & cheese but didn't save any for her and ate the entire thing him self and didn't even mention that he had even made it to begin with, and that's all he ate. He's pretty withdrawn, and I know that he wakes up pretty early in the mornings without trying to. He also seems more irritable. I think my dad is depressed. Does this sound like depression in someone in their 50's? Has anyone ever experienced this in their parents? I'm mostly asking adult children who are out of the house like I am. We lost my brother several years ago and recently I got married and moved out, so it's like another child leaving. My parents' marriage is crumbling and my mom is incredibly lonely and frustrated and I've tried a few times to get my dad to talk with one of our elders in our church to try and save it (my dad and I are involved in our church and my mom not really but is a believer). He has yet to reach out to him. My dad has a really hard time asking for help, unless it's for something that he already has a decent grasp on, like this sports hobby of his. I'm worried about him. Helpful and respectful comments please? This is very sensitive to me; please be respectful.