Rye

In a recent Finnish study, rye bread proved more effective than laxatives in reducing mild constipation and improving colonic metabolism, without causing adverse gastrointestinal effects. Researchers at the University of Helsinki randomly assigned 51 constipated adults to five groups that consumed: rye bread, cultured buttermilk, rye bread + buttermilk, white wheat bread, and laxatives (as usual for participant). The rye bread proved most effective, cutting transit time 41% compared to laxatives.
Journal of Nutrition, January 2010; epub ahead of print

In the fight against diabetes and obesity, foods that produce a low insulin response and suppress hunger can be extremely useful. Scientists at Lund University in Sweden examined the effects on 12 healthy subjects of breakfasts made from different rye flours (endosperm, whole grain rye, or rye bran) produced with different methods (baking, simulated sour-dough baking, and boiling). This cross-over study showed that the endosperm rye bread and the whole grain rye bread (especially the “sourdough” one with lactic acid) best controlled blood sugar and regulated appetite.
Nutrition Journal. September 25, 2009; 8:42

In a new study published by the Nutrition Journal, Swedish researchers report that eating rye at breakfast suppresses appetite over the next few hours much better than wheat. Attributing this to the power of rye fiber, particularly in rye bran, the researchers fed sixteen volunteers breakfasts including bread containing varying levels of rye, but all with the same caloric value. Those who ate the bread with the highest levels of rye fiber reported a lowered desire to eat in the hours between breakfast and lunch, while those who ate bread made with wheat flour felt hungrier earlier. Researchers concluded that the consumption of rye, whether through pure rye bran or sifted rye flour, created a feeling of satiety unmatched by wheat.
Nutrition Journal, August 26, 2009; 8:39. DOI:10.1186/1475-2891-8-39