Nice to know that we have studies like that.
As far as the limit of our knowledge is concerned, I have often heard that the sea is the final frontier of discovery, but my opinion is that it is our own metabolism that we need to get to know better.
We all know that exercise and a healthy diet is necessary for the body to grow and age in the best of conditions, but we don't know what exactly we need as an individual on a given day. Some people may need more or less food of a certain type than others. In a given dietary environment, it may actually be good to have a bar of chocolate at a given time of day.
What I'm driving at is the fact that we have no idea of what a particular food does to us, nor what is the best time to eat it. I'm not saying that eating fries at a given time of day will be better for us, I'm saying that we just don't know the impact, at a cellular level, of what we eat.
What we need to get to is something like Frank Herbert described in Heretics of Dune, when the character Miles Teg is visited by a local doctor. In this extract, the doctor simply uses a medical scanner on him, then defines a meal for him that will set him right. Of course, that is fiction, but it does describe a level of knowledge of the human metabolism that we are far from having today.
Studies like the one linked above will help us get there, the more the better.