My mother with dementia has started eating almost constantly. Has anyone else experienced this?

Yes, I have experienced this with my Alz. mother. It was very very disturbing to see her eating uncooked food, attempting to eat ingredients like flour, seasonings, raw pasta, unripe avocado with skin on, and even cat food. I had to lock up all the kitchen cabinets and pantry, even refrigerator, and only left on the table proper food and snacks that she could eat. For awhile, my mother was always searching for food and ate everything she could find. One time she drank a whole carton of OJ by herself. Ugh!

What a terrible disease which destroys your brain, your mind, and your dignity.

Lily, I totally understand what you’re going through.

Yup. My Mom does have memory loss. It started being noticeable when she was 98. She claims that they didn't give her lunch. She can't tell the difference between being thirsty and being hungry. And my doctor said, "be happy that she is eating."

She's 101, much heavier than she's been in her adult life, probably diabetic, etc.....and still going strong.

Prior to her entering MC a bit over a year ago, I removed all the cookies, crackers and chips out of the house. We had no pies or cakes. She loved hot cocoa and she ate fruits throughout the night. Bread surprisingly was not an issue, she had a half slice with peanut butter for breakfast and didn't want it at night. The only leftovers at night were protein or vegetables (no pasta or rice).

My motto was, only keep it around if it has nutritional value (she made her hot cocoa with milk).

Early on I broke my Husbands meal into many smaller ones.
He liked to eat so for breakfast for example I would give him oatmeal then an hour or 2 later I would give him some fruit, then about 2 hours after that he would have lunch and again I would give him some soup then later a sandwich or some yogurt and fruit.
As he declined and slept more I moved his larger meal to the morning that way I was sure he would finish most of it. Whenever he was awake I would offer fruit, yogurt or other snack. (again as he declined I had to eliminate a lot of fruits that were "slippery" so that he would not aspirate anything as a result most fruit was pureed by then. At that point I began pureeing all foods)

You do have to watch for any item that looks like food.
I stopped putting up my Christmas tree because my Husband would try to eat ornaments that looked like food or candy. I had to watch him in stores that had "fruit displays" that were fake fruit, I found him trying to eat a fake apple and he had a fake banana and fake orange in his pocket.
Leave out healthy items and let her "find" that, lock up other foods. There are magnet locks you can get for cabinets, child proof doorknob covers and latches for refrigerators.

Run your home like a managed care facility: 3 meals a day and 3 snacks, nothing else. Food needs to be locked up in the fridge and cabinets and doled out on a schedule YOU determine. Lock up lotions, soaps and chemicals too. A solid routine works best for elders suffering from dementia.

Good luck to you.

This is very common with some kinds of dementia. You will have to put locks on the refridgerator and the cabinets so she cannot get into them.
You can leave some fruit or a limited amount of some other healthy snack where she can get it, but make sure it is portioned out and limited.
You should also make sure things like toothpaste, mouthwash, body products like lotions and bath gels are where she cannot get to them. This also applies to scented candles and other air-freshening products. Especially if these things are food scented like vanilla, strawberry, etc... because she will eat them.
I had a client with dementia who would eat anything. One of the other aides who worked on the case put out one of those standing, cone-shaped air-fresheners on the table because the house always stank of incontinence. I came in for my shift and the client has all red on her face and hands. She ate the air-freshener. Fortunately, she was fine. I called the poison control and she was fine.
If your mother is at the point where she's eating continually, you have start baby-proofing and locking things up.

My MIL had vascular dementia. In the early years of the dementia, she began overeating and gained a good deal of weight, this was unusual for her. This situation changed several years later and she began losing weight rather rapidly. The weight loss was accompanied by an increase in her dementia symptoms. The last year of her life she was rather thin as her vascular dementia came with a lot of internal digestive system issues.

It is very common for all sorts of eating problems to manifest with dementia. Some experience swallow difficulties, lack of sense of smell and taste, and begin to wish not to eat at all, while others overeat, grazing as you mention throughout the day, without any idea that they already ate.
Rarely this can be a problem with frontotemporal dementias, and patients fail to recognize any feeling of being "full". There has been serious problems for some with binging.
I would watch, and discuss with your Mom's MD at next appointment. Sure wish you luck.