If as you say Myra a cup is 8 ounces and he gets 3-4 a day that equates to 24 ounces 3 cups a day 32 ounces 4 a day. Dillon gets around 20 ounces a day including his rib or chicken wing morning and evening.
Dillon as you know is a Bernese Mountain dog meant to be chunky and the males weigh in at 10 stone when mature which Dillon is and some more depending on genetics. He also has mild HD. He gets vit c, vit e, fish oil apple cider vinegar and vet vits joint supplements I do not think any of these contribute to weight.
He does get treats and is a bit of a lazy boy so I weigh out meticulously with his food and monitor treats. Some days we walk for an hour other days less some days he wants to run in the garden and not walk out. He tends to miss a meal some days his own decision and I do not worry as he is obviously not hungry.
I was told when Dillon was diagnosed he was 6 months old leash walking is good for building muscle as it makes them walk differently to when off leash.
If you can and Nigredo can put up with it I would lessen his intake it does seem a lot if I am reading the amounts right bulk it up if possible with steamed green beans. Good luck I always had trouble keeping Ollie's weight under control and not saying this is Nigredo's problem but he did have a lot of underlying health issues so just saying I sympathise with the problem.

If you have been feeding a cup of 8 oz 4 times a day, you have been giving him around double the amount of food he needs

8 ounces = 225 grams

That's 900 grams a day, as Lynn says Dillon ( who is a much bigger dog ) does not get anywhere near that amount, cutting it down to 3 is still far to much for him, that's why he is not losing weight,

On the chart I put up, even a dog of 50 kg is on less than half of what you feed, you brand of food my be different , but it won't be that much difference .

Not sure how raw in density works out against kibble as Dillon is fed raw if he was on a kibble he would not be getting 900 grams a day. If he was energetic that is the recommended amount and the top end. For a less active dog it is around 750 grams tops recommended. That is James Wellbeloved not sure what other brands recommend.

Mmm... well when you put it that way, it does seem as if he gets too much. But it's not making sense to me. Let's say he's a whole 10 lbs too heavy. An 80 LB dog according to the bag should get about 3 cups of food at least. There is really no way I should be feeding him only 16 ounces of food a day, right? He's REALLY going to be unhappy, but if that's the right amount, then that's what I will do. 20 ounces of food for a giant breed seems like nothing, especially with kibble. IDK how people can get dogs to eat foods like green beans, Nigredo won't touch that.

In other news, I gave him a bath and my brother and I spent an hour grooming him, and his coat looks better. A bit thin, but a lot better. He's still very fat, as you can see... but his coat looks better. He wasn't dirty, but the subcutaneous fluids they gave him on Thursday were in his coat a lot and it was good to wash that out. I will (extremely reluctantly) slash another cup of food from his diet and we'll see what happens in a week. Wish my big man good luck, I'm trying and I know he is too!

What you have to remember is that what you think is not a lot of kibble will treble in quantity when it is wet ( in his stomach) try soaking on of your 8 oz cup full of food and leave it to expand and you will see how much he is actually eating.

Dillon weighs 62 kgs 10 stone or 140 lb if he was a very energetic Bernese walking miles on or off leash and running about a lot more than he does then he would get more food he is not an overly energetic dog some days we walk an hour on leash some half an hour and I have to occasionally cut his portions down.
The rule of thumb with raw is 2-3% of total body weight if I fed 3% of his body weight he would be getting 4lb of food daily.
2% he should be getting 2lbs daily but he doesn't firstly because he doesn't burn it off secondly it would be no good for his joints. He is perfectly ok on 16 to 18 ounces a day split into two meals. Plus some treats.
If he was out all day and night like his breed is meant to be being a watch dog and pulling carts during the day and herding the livestock then maybe 2-4 lb of food would be acceptable depending on his metabolism but as he isn't and he can be a couch potato most days it really would not be good for him.

I always mix the green beans in with food if feeding them but feeding raw is probably easier to disguise them especially with his evening meal when he also has yoghurt and cottage cheese included.
Will Nigredo maybe eat some raw carrot as a treat or apple some pear even, maybe the odd strawberry ?

He ate his TOTW food instantly (1 measured cup) and looked around for more and gave me the sorriest look I've ever seen. He started whining a while later. He normally got 2+2 cups split into two, and recently he got 1 cup for breakfast and 2 cups for dinner. He was NOT happy with his one cup.

He then jumped on my bed and refused to get down. He followed me down for my dinner. He sat and begged for my food. He also made a move for the kitchen, which he's never been allowed in (and has never dared to put his paws in), and my brother had to tell him off.

After being put into my room for being an annoyance, he hollered and tried to escape, which he never does. My mom also shouted at me when I answered why he was so unhappy, saying "it's not right" to do this to him. He can't sleep, so I can't sleep... so it's 3 in the morning we're awake.

I gave him a carrot, which he picked up and subsequently laid on, and then tried an apple slice, which he wouldn't touch. Can't see me being able to get him to touch any of that, I have no idea how people get dogs to eat that stuff. The only fruit he will eat are sweetened cranberries, which are NO GOOD for him. He will not eat them fresh or dried with no added sugar.

This ISN'T going to work for anybody here, especially now that my mom has decided I'm being mean to him and is going to get in my face about it. I've got to find a way to fill him without fattening him, and aside from a diet food... don't see how that's possible, so I'm going to have to bite down and find one and see if it works ASAP.

He's currently in my bed, I gave him a hug and apologized to him. I feel so bad for him, he's so unhappy. I ALMOST gave him more, but I didn't. I have a feeling that I won't be able to keep this up very long. It's been quite some time since I've been up all night like this, can't say I miss it.

Took this pic last night after I gave him his food. Look at his little face. He's SO SAD, and the puppy eyes almost won him more food. I feel so bad for him, I really do. He's so unhappy all the way around. He acted totally out of character, which I semi expected but not that badly.

He has to finish this bag first, but I can only hope he can get used to being fed so much less. If it continues to torment him like this, I won't be able to stick to it. I can't stand seeing him so unhappy, it isn't like him. Nigredo is a happy go lucky dog, he's isn't an annoying problematic dog.

Its hard Myra, maybe cut it down slowly not in one full hit.
That way he will gradually become accustomed to having less and his tummy will begin to accept less bit like ourselves when dieting you have to cut down or cut out the bad things slowly.
If you were giving him 4 cups a day cut to 3 then down to two a day. If he is getting 3 cups I would now give 21/2 then down to the 2. That will mean he is getting 16 ounces a day which if he weighs 80kg should be plenty with the odd treat. If you find he exercises more then give him a tiny bit more if he doesn't leave it at the 2 cups.
Its true what Jackie says about kibble it expands. Those puppy dog eyes get us every time.