Careful-Lots of Hype. Hydrogenated means hydrogen atoms added to break c-c double bonds (unsaturated) to single bonds, aka saturated (no room for more hydrogen). If partial, then some double carbon-carbon bonds still present. Living cells make only cis-bonds. Vast majority of c-c bonds in all fats are single. The myth that sat. Fats were bad: ancel keys 1953, has driven obesity, dm & cv ds. Study gary taubes, nusi.Org.
Hardly any. Partially hydrogenated oils are hazardous becuase they contain toxic trans fats. The amount of trans fats is 50% the amount of partially hydrogenated oil. Either way, these should be avoided. But be careful- a food can claim to have "0% trans fat" and still have 2.2 grams! see www.Treelight.Com/health/nutrition/transfatlabels.Html & www.Treelight.Com/health/nutrition/partiallyhydrogenatedoils.Html.