Raymond sent me the PhD thesis of Valerie Reeves, Kentucky University.
Reeves, Valerie Lynn, "A DIET ENRICHED IN STEARIC ACID PROTECTS AGAINST THE PROGRESSION OF TYPE 2 DIABETES IN LEPTIN RECEPTOR DEFICIENT MICE (DB/DB)" (2012).Theses and Dissertations--Physiology. Paper 3.
Before we think about leptin receptor defective mice (another day), we can ask questions about the control groups. Such as:
What happens if you feed a fairly typical C57Bl/6 mouse 40% of its calories from fat, based on fully saturated stearic acid?
They stay significantly slimmer than they do on CIAB (chow) and probably slimmer than when fed on 40% oleic acid (olive oil w/o the PUFA).
(EDIT As Tucker pointed out in comments: You might be able to explain the relative weight gains in terms of omega 6 PUFA. Chow was about 13% of energy as PUFA, stearic acid diet about 5% PUFA and the oleic acid diet about 14% PUFA. The correlation of PUFA with fat gain isn’t perfect but it’s quite close… END EDIT)
Now this is clearly impossible, as anyone who has read anything about Bl/6 mice and fat will be very aware. So the poor girl did it again:
This time we have p values sprouting all over the graph like mould in a Winter bathroom. For mice, chow makes you fat. Olive oil makes you fat. Stearic acid doesn't. Impossible I know, but that's twice it has happened. For fat mass the p values never make pay dirt but the writing is on the wall for oleic acid and fat gain too:
The wild type control mice were so nice in this PhD thesis that I thought I'd just put up these few figures before we consider what might happen if (gasp) you put an obese, diabetic db-/- mouse on a highly saturated stearic acid based diet.
I think palmitic acid would do exactly the same as stearic acid did for these mice. But who would risk their career with a finding like that? The corollary is that when you see a C57Bl/6 mouse get fat on a high fat diet, you know there are lots of double bonds in that fat........