To me a very acceptable sweetener (endulzante) is a mix of Stevia and honey* or, dark brown sugar and Stevia or Molasses and Stevia. If you purchase Stevia make sure it is 100% Stevia and not the stuff I found in Costco -- 97% sugar and 03% Stevia (huge letters STEVIA on the box).
Melaza molasses, is not commonly found in stores so I bring jugs from the states. Same for Stevia. The little packets of Stevia help prevent it from lumping.
*Molasses and Stevia need liquid so to the horror of my kids I make t-h-i-c-k oatmeal (sacrilege to Mexicans who gulp thin oatmeal out of a glass). I use extra milk then stir in the sweeteners (endulzantes) and molasses.
Look for stores titled Semillas Y Granos downtown in larger towns and cities.
Many of these stores have unpackaged, loose (suelto) dried fruits, nuts, cereals and grains at scarcely believable prices. Don't be surprised to see oatmeal priced at less than seventy US cents per pound. Almonds, dates, and granola. Rice, and jellied fruits. Zip Lock stuff headed for the beach.
DIABETICS: Take lots of test strips, lances and an extra set of batteries. Mexico has lots of test supplies in cities these days although the price may make your hair stand on end. METFORMIN (glucophage) comes in 850 milligram size and GLIBENCLAMIDA the generic name for USA GLYBURIDE (verified and then quadruple checked via chemical formula) is only available in 5 mg dosage, the pills are nearly impossible to split even using a pill cutter. One side or the other will ricochet many feet away. Patented (flagship) diabetic medications are available in Bodega Aurrera, Wal-Mart, and Comercical Mexicana. Verify with your home pharmacist about high temperature and your Type I or Type II diabetic medications. By the way fresh squeezed orange juice seems to work much faster to treat excessive dosage of blood sugar lowering medicines.