A method including reacting carboxylic acids obtained from fermentation and a carboxylic acid recovery step from said fermentation to produce short- or medium-chain triglycerides, wherein the reacting carboxylic acids comprises direct esterification with glycerol in the presence of a catalyst. Such method mentioned above wherein the produced short- or medium-chain triglycerides are further interesterified with an oil, butter, fat or other lipids in the presence of a catalyst to produce structured lipids. Yet another method comprising reacting carboxylic acids obtained from fermentation and a carboxylic acid recovery step from said fermentation to produce structured lipids, wherein reacting the carboxylic acids comprises transesterification with an oil, butter, fat or other lipids in the presence of a catalyst. The use of such short-chain triglycerides, medium-chain triglycerides and structured lipids as nutritional additives, dietary supplements, or both.