Intranasal insulin does not, under any circumstances, reduce food intake or bodyweight in women.
That's half the population.
Hallschmid's lab gives us all of these:
Intranasal insulin reduces body fat in men but not in women
Differential sensitivity of men and women to anorexigenic and memory-improving effects of intranasal insulin
Comparable sensitivity of postmenopausal and young women to the effects of intranasal insulin on food intake and working memory
So. What about this via Wooo:
Postprandial administration of intranasal insulin intensifies satiety and reduces intake of palatable snacks in women
It's free full text if anyone want's to read the details of the convoluted protocol involved. Take my word, you will regret it. Here's the executive summary
You can summarise the results by saying intranasal insulin puts women off of Chocolate Chip Cookies. At least those made by Coppenrath of Geest in Germany. Maybe this will happen with chocolate Hobnobs in the UK or some sort of Oreo in the USA. Who knows? The subjects just filled up on the Premium Spritz Cookies and the Crunchy Coconut Cookies, all made by the same firm. There are lots of soft end points with low p values in the study. Hard end point to me is calories.
Does intranasal insulin affect total calorie intake of cookies, even in the convoluted protocol used?
I have no idea why intranasal insulin is ineffective to speed cellular repletion in 50% of the world population but it makes me suspicious that women deal with calories slightly differently to men and that we're not going to find out how or why from squirting insulin up anyone's nose. And that insulin is not a satiety hormone.
I think I need to get outside more.