I struggle here too, b/c I also have their Amex card, and it's pretty much the only thing I use it for, so when the bill comes, I can tell how good or bad we've been in the prior month.
I feel like we should spend less, but I've come to terms that some months our expenses will be higher due to purchasing bulk items that will last a long time. For example, one month I spent $75 on generic Allegra, but I saved $15 over the course of the year by purchasing it while they had their coupon sale.
We shop there weekly, but we skip most of the store. Bakery only for bread or if we need to bring a desert to a friend's party - their $10 red Velvet cake is hard to beat. Nothing in housewares, electronics or clothing, except on the rare occasion where hubby needs new underwear or something like that. Produce - this is where we spend most of our money. However, not everything is a good deal, so I know my prices and buy what's cost effective. Frozen we only do for wild caught fish. Things like toilet paper and detergents are a very rare purchase. Everything else is as-needed - cereals, quinoa, nuts, soy milk.
I also have to remind myself that since we buy things that aren't part of the grocery budget, the overall monthly cost may seem higher, but overall, I'm doing pretty well. We keep to our $200 - $250/mo grocery budget pretty well, on an annual basis.