Sorry, but when I tried living on nothing but dates, and more dates, for a week, they worked the other way. I know they have a reputation as a laxative. For example, they really do help ease a diet of white bread. But, try eating nothing but dates and water for a week and tell us how your tummy feels!
After a week of dates, my tummy needed all the Ex-Lax that we had in the truck, and then I went back to eating the military MREs : ( Maybe it is just the dates of Al-Hufuf. (I bought a 30 kg wooden crate of dates there.) Maybe it is the fact that my dates were dried, rather then fresh. With all the smoke from the burning oil wells in the air, it never really got that hot during that summer of 1991, and we had plenty of water, so I do not think dehydration was much of a problem. Maybe, it was the fact that we were pretty active, so I was hungry and ate a lot of dates, but those dates sure plugged me up. My partner ate crackers and canned tuna fish when he got tired of MREs, and he was OK. I was OK when I was eating MREs, so I do not think it was the smoke. I was OK when we got into Hofer Al-Batin (north of Al-Qaysumah) and I was eating hotel food (Actually that was some of the best food I have ever had in my life. Somebody in that kitchen knew everything there is to know about grilling lamb chops!)
Hofer Al-Batin is also the home of the great Bald Hills Dairy Camel Herd. I bought half a liter of camel's milk at the little store at the cross roads. ( Mostly they stocked dates, flour, and lamp oil.) The camel's milk was a whole lot more powerful than the Ex-Lax. And, I had looked and not seen camel's milk in the BIG supermarkets in Al-Khubar and Ad-Damman where I had bought provisions.
I have never tried living on just raisins or prunes. In my early climbing days, I often lived on granola that was half dried fruit, including raisins, prunes, or dates, and there was never any problem at all. But, there was lots of nuts and grain with the dried fruit! But, in my one experience, dates in excess, plug! : (
If there are dates around, I eat them! But, I do not try to live on them!
Aaron