I think it is possible to go insanely low on groceries in Sweden if you specifically base your diet on whatever it is your local supermarket is using as their loss leader in a given week. Like, every week they will be selling something for 5-10 SEK (a dollar is 8 SEK I think now?) that would normally cost 2-3 times that. On top of that they will usually sell stuff that is about to expire for 50% off regular price. I suspect something like this is behind this figure.
Also, fresh bread is ridiculously expensive in Sweden so baking it definitely pays off even if you use the fanciest ingredients, let alone if you just mix dry yeast with flour and bake that.
While i realize that vegetables and fruits may be expensive over there, especially if you want the good stuff - this is not really the case here. Just yesterday i bought another 4.5 lbs bag of potatoes for under 2$. 4.5 lbs of potatoes can last a person for a week, if mixed with proper vegetables and other things. I don't even recall the last time i bought rice, because i bought 2x10lbs bags when they were on sale at extremely low prices. As havregryn says, each week usually each grocery store will have certain items off. Another example is apples. I buy a bag of apples with 10-12 apples in it for 70 cents. That'll last me a week's worth of shakes.
Honestly, my biggest problems are the more "exotic" fruits. bananas, for instance. They rarely drop below 2$/2 lbs. And i like bananas. That's where i have to splurge a bit. Another fairly high cost is good OJ, because i want actual orange juice and not concentrate. That'll run me maybe 2$ a week, though i use very little for each shake.
I buy my musli and granola in bulk packs of 1 lbs each - the cheapest kind, but i taste no difference between that and the 6$/450gram musli. Runs me maybe 4-7$ for a month or so. I buy eggs in packs of 20/24 when there's a sale (usually at one store or another) for 1.60-1.80$ for the pack.
My ex was the one who told me that it essentially was not possible to live this cheaply (and she was from Seattle) buying only your "basic" foodstuffs. It's entirely possible here though. What costs money is tv-dinners (3-5$ each), snacks and soda (2-6$ each, though you can get it cheaper) and your GOOD cuts of meat (which can run you over 25$/kilo. which i don't buy).
Oh, and the reason i said that it's possible to go below 60 for next month is that my local store just sent me 4 coupons for 5$ off (if you buy over 10$ worth of groceries). Adding that up easily could come to that, if i consider the spending carefully.
High fiber bread? No. I mix the flours quite a bit. I try not to make too much "white"bread, it's usually 50/50. Gotta be careful with flour because as you say, usually it's not that cheap. I buy in bulk when there's a sale.
Chicken is rich in protein, controls the Homocysteine levels in your body, rich in phosphorus, Selenium, Vitamin B6, niacin, various vitamin A derivatives that promote eye health and has a lot of riboflavin (which is good for tissue growth). All in all, it's a very healthy type of meat. Granted, you have to prepare it properly and there is some bacteria in it, but to say it's unhealthy...nah. Plus it tastes great :).
My diet is based around potatoes, rice, pasta and bulgur. I mix this with a lot of carrots, celery, parsnips, leek, onion, beets and salads. For meat, i put in chicken and once a month or twice a month i buy a package of sliced, smoked ham. I prepare large quantities of slow-cooked meats or "pans" of fried potatoes. Lots of eggs with it. I eat plenty of fruit (though i'm not sure i reach the daily recommended intake - then again, i don't personally know anyone who does). I drink tons of water. My liquids are water, my shake and coffee as well as the occasional cup of tea. Being german (but living in sweden), i also drink quite a bit of beer.
I consider myself pretty healthy. I'm 6"4 (around 195 cm) and weigh about 185 lbs. I've always been on the lean side, even in school when i had a much fat-heavier/protein-heavy diet. I work out daily or every second day (cardio and weight-lifting) and i'm pretty sensitive to not "getting" what i need food-wise. So far, and having had this type of diet for almost 7 months now, i haven't noticed any negative effects whatsoever :).