It seems to be settled that dogs should be fed at least two meals daily about 12 hours apart. Dr. Desmond Morris, the renowned zoologist and author, makes some interesting comments on this (Dog Watching). He says that most owners give their dogs two feeds a day with freshwater. This is fine provided the food is varied. It should not be restricted to meat because in the wild grey wolves eat the contents of their prey animal’s stomach which contains vegetation. The prey animal of the grey wolf is a herbivore and domestic dogs have a similar nutritional need.
There was a time when vegetarianism and veganism became more popular, which is still the case. And as dogs are omnivores, like humans, some vegetarians/vegans probably think that they can give the dog a vegetarian diet, but Dr. Desmond Morris says that this is even worse than an all-meat diet. Being an omnivore the dog like the human requires a balanced diet.
There was a phase apparently when dog owners would fast their dogs in much the same way that the wild ancestor of the dog, the grey wolf, was also forced to fast from time to time because of a scarcity of prey. Some people devised a food-deprivation regime to mimic this wild behaviour.
Sometimes wolves can be without food for 14 days and survive. These fasting periods are then followed by a massive gorging. Some dog owners decided that this was a natural feeding pattern which occurred in nature, and it should be the preferred method for domestic dogs. Dr. Desmond Morris says that this isn’t the case because when prey is available wolves eat several times a day. Yes, they can survive on a diet with considerable gaps in it, but this should not be taken as a guide for dog feeding.
And Morris also states that humans, back in the day when they were primaeval hunters, would survive with long gaps in their feeding. On occasions they might have survived on a gorge-and-fast diet. As our ancestors had this kind of diet from time to time so could or should humans today but the argument is that we can thrive better and be healthier on a regular, several meals a day, diet. However, there are advocates of fasting to improve health.
There is a discussion about whether humans and indeed our dog companion should be fed smaller meals more often. Personally, I have found that I can control my weight better, as an omnivore, if I eat smaller more numerous meals. It seems that the stomach adjusts to smaller amounts and in becoming acclimatised to this my appetite is suppressed.
I am not saying that my stomach shrinks because this does not happen if you eat small meals. But what might happen is that the stomach does not send signals to the brain that you need food in the same intensity as it might when you eat large meals.
And I wonder if an overweight dog might benefit from not only a weight reducing, low calorie, food but also smaller but more numerous meals. You will find articles on the Internet for humans about curbing food cravings by eating smaller portions. Many experts advise against eating fewer large meals daily. And for humans, some studies have suggested that increased meal frequency can improve blood fat levels and reduce the risk of heart disease.
It seems entirely logical that you could feed your dog several small meals a day rather than two big ones because that too would be natural for the wolf if living in an area where prey was abundant.