When I was budgeting paycheck to paycheck, I created a Monthly Variable category to save for next month's groceries, household, and fuel (I didn't know exactly how much I'd spend or when in those categories).

If I were in your situation, I would decide on a total monthly value, and budget 1/4 of that value each paycheck to the Monthly Variable category.  Then, when the month turns over, you can empty the Monthly Variable category into your Groceries and Dining Out categories and use them usefully for spending guidance.

To get there, you will have to fund your current food needs as well as next month's, but once you're past that squeeze, you'll probably find that you're being more efficient with that money, as you have better information to guide purchasing decisions. It was very worth it for me.

Is the Issue that you want to make sure you don't go over X amount per week? If so, you can make a Category Group called Groceries and Divide your overall grocery fund into subcategories for each week. Then, you will know at a glance how much you have left each week.

It’s ultimately a psychological thing. YNAB will give you the tools to understand exactly what decisions you’re making but it’s up to you alone to ensure those decisions are appropriate (is it OK to top-up the category endlessly or do I need to stop spending).

dakinemaui said:
The $50 Available prohibits planning lavish dinners for the coming week.

 My understanding is that the OP would never see $50 in available because they always topped it off to $500 available, weekly. 

So, if they spend $175 in week 1 (top off to $500), $150 in week 2 (top off), and $125 in week 3 (top off), it looks like they have $500 available for week 4 and can splurge. But really, if they wanted to spend $500 in the whole month, they shouldn't be topping off - then they'll see $50 available and can make choices. 

I think your analysis is correct - they need to decide what interval they will budget with. If they're adding money each week to groceries, add $125 and make spending decisions based on that. If they want a monthly balance of $500, start the month with it and let it be spent down and give good information throughout the month. 

If OP is not ready to budget all categories a month at a time, but they're effectively ready for a month of food spending at all times, why not keep the budgeting cycle strong, but separate from inflating spending decisions? The Monthly Variable (could also be called Next Month's Food) category facilitates that, and is a model for developing INM.

Move Light Sound Life said:
you will have to fund your current food needs as well as next month's, but once you're past that squeeze

 Actually, you'd only have a week's worth of a squeeze - you've already got them funded at their full amount. Just move your currently available Groceries $500 to the Next Month's Food (I like that name better than Monthly Variable. You can, of course, do whatever you like), and budget $125 (or whatever) for this last week of May. Ok. You might have to squeeze $125, but that's better than the whole $500. 

If you're planning to add money weekly, then the category should hold a weekly amount. Holding a month's amount results in 3 weeks worth of money that is tied up doing nothing. Reallocate and put it to better use.

Alternatively, if you want to budget in month sized chunks, then do that on a monthly period. Put the money that would have topped up groceries during the month to a better use.

Again, none of this is specific to Groceries. All categories work like this.

Move Light Sound Life said:
So, if they spend $175 in week 1 (top off to $500)

Sounds like a waste of about $300, maybe more. Actually, waste is not the right word. Perhaps poorly planned is better.

The point of dividing up funds is to plan. Every dollar planned (budgeted) for X cannot be used for Y. This sense of scarcity is what cements an understanding of our priorities. Without it, we drift aimlessly with little direction.