Fat does compete with glucose for uptake, and various free fatty acids have direct and indirect signalling effects that favour fat as fuel vs. glucose. This decreases the demand for glucose in cells that can burn fat for energy. On the glucose side, a similar thing happens. If lots of glucose is being metabolized in a cell, there are pathways that decrease fatty acid oxidation and shunt free fatty acids towards storage as triglyceride.

Normally after a high carb meal, lipolysis decreases in fat cells and free fatty acids are greatly decreased in the blood, this decreases fat as an option for metabolically active cells. So they're more receptive to the incoming glucose, more sensitive to insulin. Dietary fat eaten with carbohydrate can interfere with this effect, since there's an overlap of fat and glucose entering the blood stream. More fat does mean more competition with glucose for uptake. But more glucose means the same to fat. Eating pure fat requires almost no insulin secretion. Eating a mix of fat and glucose, the fat increases the amount of insulin required per gram of glucose. The body gets a mixed signal. So things are a bit easier when the ratio of fat to carbohydrate is to one or the other extreme.




http://high-fat-nutrition.blogspot....d-dr-davis.html

This is my favourite blog on the subject.



No, but within a certain range, replacing the potato calories with butter might.