The only downside to it is the length of time it takes to cook. (thepretendchef.com)
The only real downside to them is that they tend to be slightly more expensive than their chemical - filled counterparts. (momtricks.com)
That said, there are downsides to it as well, and I certainly don't think it's the best fat loss strategy for everyone, all the time. (straightforwardfatloss.com)