High protein/fat?
It depends upon how high a fat intake you actually have, unless it's very high fat , if its also low carb then it will necessarily be quite high protein.
The French had a detailed investigation into a wide variety of various diets a couple of years ago.
The highest fat diet they considered was first stage Atkins* (and the Cohen diet )
First stage Atkins was 59% fat content with 35% from protein . This is slightly less fat than the PRCM document linked to by Izzzi but the protein is still considered high.
For women they suggested that it amounted to more than 2g/kg of weight (ie normal weight) They term the regime as High fat, high protein, low carbohydrate. ( the French home grown low carb diet, Dukan is much higher in Protein at 53% for women in stage 1, they really don't like that one ) The French nutritional guideline say 0.83g/kg .for protein
I won't go into the whole paper it's very long and detailed and evaluates many weight reduction diets, mostly unfavourably.
In the summary report there are two tables, one for women, one for men that are probably easy enough to understand. They include info on the vitamin and mineral contents . Atkins covers the first three lines of the grid. If someone is eating this type of pattern then it might be worth looking at where there may be too little (or too much) and look for foods that can 'plug' the gap.
The pink highlight is for deficiencies and the yellow one for where there is a higher than the normally recommended amount. Red writing for sodium stands for more than 5g
Inca is what French population actually eat according to national surveys
ANC are French guideline amounts
BMN are average nutritional requirements
(so French women on average eat 39% fat and the guidelines say 35-40% )
http://www.afssa.fr/Documents/NUT2009sa0099.pdf
*This is the paper from which the French derived the proportions and nutrients of the Atkins diet . It has a couple of sample menus that presumably they used for analysis.
http://www.colorado.edu/intphys/Class/IPHY3700_Greene/pdfs/atkins/freedman.pdf
If you do read French or want to use Google translate their is a section in the full report specifically on low carb diets P 52. with lots of references to studies , mostly in English.
There are also lots of graphs and diagrams comparing the various diets visually. This is a very long PDF.
http://www.afssa.fr/Documents/NUT2009sa0099.pdf