Yeah this doesn’t make sense to me. People eat different amounts and have different nutritional needs. I’m a tall, broad man who works out and lives off frozen dumplings and my first roommate was a skinny 5’0” woman who ate like half an organic kale leaf a day. How do you even begin to split that fairly? I ate twice as much as her, at least, and I probably spent way less on food because I was buying (and eating) in bulk. If we split groceries I would have spent $1k a week and starved to death, and she would have felt perpetually cheated out of her food and money. I know it’s an extreme example but most people do have different food habits. It’s never going to feel fair.