Three recent studies, one RCT, a Meta-Analysis of RCTs and a non-random control trial.
Aug 2020
Conclusions Weight loss resulting from consumption of a diet lower in CHO and higher in fat may be beneficial for older adults with obesity by depleting adipose tissue depots most strongly implicated in poor metabolic and functional outcomes and by improving insulin sensitivity and the lipid profile.
July 2020
The effects of ketogenic diets on glycemic control were greater for diabetic patients relative to those of low-fat diets, indicated by lower glycated hemoglobin (SMD, −0.62; p < 0.001) and homeostatic model assessment index (SMD, −0.29; p = 0.02), while comparable effects were observed for nondiabetic patients. Ketogenic diets led to substantial weight reduction (SMD, −0.46; p = 0.04) irrespective of patients’ diabetes status at baseline and improved lipid profiles in terms of lower triglyceride (SMD, −0.45; p = 0.01) and greater high-density lipoprotein (SMD, 0.31; p = 0.005) for diabetic patients. Other risk markers showed no substantial between-group difference post intervention. Our study findings confirmed that ketogenic diets were more effective in improving metabolic parameters associated with glycemic, weight, and lipid controls in patients with overweight or obesity, especially those with preexisting diabetes, as compared to low-fat diets. This effect may contribute to improvements in metabolic dysfunction-related morbidity and mortality in these patient populations.
June 2020:
And an article (non-random control trial) claiming keto is bad for athletes.
Crisis of confidence averted: Impairment of exercise economy and performance in elite race walkers by ketogenic low carbohydrate, high fat (LCHF) diet is reproducible
this study was able to investigate (and disprove) a hypothesis based on anecdotal observations about successful performance in athletes
The study is an extremely short duration (1 month) investigation into the ketogenic diet for elite race walkers. 3.5 weeks into the ketogenic diet and my exercise performance was trashed. Study itself seems to be of high quality, but that part of their conclusion based on this study doesn’t seem justified. But I would say that, wouldn’t I 
Do agree that the following could be very interesting
The potential models involving periodisation of CHO availability, or alternatively, the integration of high CHO availability within a background of keto-adaptation are numerous, and also merit investigation.
