2nd 3rd optional. FDA has announced an official date of 2010-06 when they will accept submissions to 3 rd edition. The 3 rd Edition will be Mandatory 2013-06-01. Health Canada has announced a mandatory date of 2012-06-01. The EU date of 2012-06-01 has been published in the Official Journal.
I don't know what you mean by root word. Lipo - is the root for fat and used often at the molecular level. Adipose - is the word for fat tissue. fat: <biochemistry> A triglyceride (lipid) that is usually solid at room temperature. http://www.americanheart.org/presenter.j...
Fat is one of the three main macronutrients: fat, carbohydrate, and protein. Fats, also known as triglycerides, are esters of three fatty acid chains and the alcohol glycerol. The terms  oil , fat, and  lipid  are often confused.