There are many different ways to classify fat: saturated, trans, unsaturated, brown, white, and essential fatty acids. Some are essential for life and some are lethal. Where fat accumulates is also important. If white fat accumulates inside the abdominal cavity it predisposes to the metabolic syndrome and type two diabetes with all of its complications. However, if it accumulates in other places, it actually extends life expectancy!
Brown fat accumulates in the neck in humans. Contrary to white fat which stores fat and makes us overweight, brown fat burns fat when the body is exposed to cold and is associated with a lower body weight. Wouldn't it be wonderful if we could convert white fat to brown fat so we'd tend to burn it and weight less? Maybe not! So far, drugs that do this have been lethal.
I find it very interesting that we're always looking for ways to subvert the way nature operates rather than live a healthy lifestyle. It is also interesting that fat is a highly active tissue metabolically. In general, we have a fat phobia in this country that is off target. Fat is a healthy food and what our body burns for fuel most of the time.