What is low and high fat depends where you are coming from, there is no accepted definition.
There are proponents of very low fat diets ie less than 20% .They tend to be vegan and there are studies to suggest that the work very well.
The UK suggests that 33% fat is optimal.
I'm in France and the guidelines say 35-40%
The Cretan diet investigated by Ancel Keys had 42% fat
The Predimed (Spanish Mediterranean diet) which had very successful trials recently had 39-41% fat (high in monounsaturated and not much higher in fat than the control at 37% (difference was type of fat and carbs)
Trudi Deakin suggests that she eats 82% fat.
Here's a paper suggesting that a high fat low carb diet is less than 20% carb and 55- 65% fat.
In grams that is characterised in a diet of 1414 calories by
94g fat, 35 g carb, 105g of protein.
http://onlinelibrary.wiley.com/doi/10.1038/oby.2001.113/full
If the past is anything to go on, very few people on here eat anything like 80% fat .They may eat significantly more than the UK or even the French guidelines of up to 45%
Here's a thread where a member plugged in peoples sample diets to a database and worked out relative percentages.http://www.diabetes.co.uk/forum/threads/share-your-diet.30311/
You can see that it was then very few that approached 80%
(and I suspect that the levels of fat were higher than, than a similar exercise a few years previously, unfortunately, now disappeared into the ether.)
.
It's not difficult to work out your own percentages(I'd offer but I'm off skiing next week) It does depend on a) weighing what you eat.b) making sure that the data base you use for nutrient content is accurate (ie from 'official' sources, not crowd sourced and consistently from Europe or the US,not a mixture)
I suggest that butter on cheese is a backhanded reference to why Ancel Keys chose an area in Finland for the seven countries study. There the farmers buttered their cheese and had a very high rate of cardiovascular disease.
general reference
http://www.uh.edu/engines/epi2469.htm
Here are all the papers from the Finnish arm of the study (for those who look at populist knocking of this study, just look at the breadth of subjects being investigated over many decades) http://sevencountriesstudy.com/study-findings/publications#finland
To make cream, butter and cheese, you isolate the fat from milk. Hardly any of the sugar comes with the fat, but stays in the liquid milk instead. So the fat products are naturally almost zero carb, whereas liquid milk has all of the original sugar.
