I have a question more than a comment. I have been mathematically modeling the shrinkage of the brain associated with increase in age and in association with depression. I am using aerobic fitness as a primary variable which declines with age. I use relative fitness, an age independent variable that expresses a person fitness level as a constant. Runners, for example have a high relative fitness (endurance trained). Sedentary people have a low value. While, I have good r-square value in predictions of change in depression over time for a classic study at Duke comparing exercise to medications, I am uncertain of the beginning boundary conditions. In the book, Spark, it is reported that we have about 5 % brain shrinkage for every 10 years of age starting at about 40 years of age until about 70. I suspect that the shrinkage starts slowly after maturity from about age 30 and increases as aerobic fitness is lost and as the brain is used in routine, non-complex or creative manner instead of learning and process new information.

My question, were the people in this study with brain shrinkage physically active (high VO2max) or were they sedentary?

I've been struggling with eating for a long, long time. My issue is similar to that of a Mr. Ben Spencer, who passed away last October. I'm 18, used to be 'morbidly' obese myself, spent a long heavy period through something between bulimia & anorexia to lose it off have become slightly underweight. Still in that state but difficult to control weight lately kind of but I keep trying. It's plagued me ever since, my memory isn't what it is, I find myself to be suddenly quite clumsy & disorganised, and very forgetful. I would seriously not be surprised if going through a state of starvation has an effect on the memory/mind - cause I'm definitely feeling it.