summerset

While shuffling down a longevity rabbit hole on PubMed, I found a fascinating recent study in the area of calorie restriction and longevity.  What I wasn't expecting was its findings on low protein, high carbohydrate diets. 
The study found, amongst other things, that low protein, high carbohydrate (20% fat) was associated with the greatest longevity and best overall metabolic health in spite of a tendency to weight gain as fat. The improvement was equal to caloric restriction alone, and combining the two had no additional metabolic benefits (LPHC also tended to expend the most energy)
The version of the experiment where LPHC was combined with CR had the same longevity, but also avoided the increase in body mass from the high carbohydrate Intake. They also had the best immune systems
The low carbohydrate, high protein group were found to have reduced longevity and poorer cardiovascular and metabolic health, though again, LCHP group with CR fared better than those allowed to eat freely.
The area where LCHP created an advantage was in reproduction. Not in fertility, but in the actual process of reproduction, which makes complete sense.
You can read the whole report here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4472496/
It should be mentioned this study is still one part of decades of research on Calorie Restriction and dietary composition.
From the strong evidence in favor of dietary restriction, we should all be seeing increased life spans (depending on age of intervention, some will be more modest than others).
But I wonder how the evidence building up for HCLP can be applied to us.
HCLP emphasizes low glycemic index carb sources and 5-15% protein intake, but at our level of consumption 600-1000 calories a day in maintenance depending on your needs), that would only be 12.5-37.5g protein which seems like it would result in a deficiency. The famous Okinawan Ratio is on the low end of that, though people studied consumed about twice the calories (if I remember right, and I might not) which is still only 25g protein/day.
And yet, I'm not seeing any of these deficiencies in the literature. No deficiencies in the Okinawans either. 
Curiouser and curiouser.
What do you think? What did this study make you wonder?