The present invention relates to compounds of phosphonic acid-containing T3 mimetics and monoesters thereof, stereoisomers, pharmaceutically acceptable salts, co-crystals, and prodrugs thereof and pharmaceutically acceptable salts and co-crystals of the prodrugs, as well as their preparation and uses for preventing and/or treating metabolic diseases such as obesity, NASH, hypercholesterolemia and hyperlipidemia, as well as associated conditions such as atherosclerosis, coronary heart disease, impaired glucose tolerance, metabolic syndrome x and diabetes.