Protons (72) Humans: 8% LA vs 74% LA by sustained oral ingestion

This study in humans is very different to the previous rat study. People were fed repeated oral fat loads (you could call this Bulletproof Cocoa rather than Bulletproof Coffee), once an hour for 12 hours then every two hours overnight until the start of an hyerglycaemic clamp at 24h, through which the oral fat loading continued. Glucose was infused to a stable 20mmol/l and insulin allowed to respond as best it might. Insulin sensitivity was determined by the glucose infusion rate in the last 30 minutes of the clamp. In some ways this is more physiological than the hyperinsulinaemic euglycaemic clamp, which is considered the gold standard. The oral fat ingestion was slightly above calculated 24h caloric requirements for these subjects.

Differential effects of monounsaturated, polyunsaturated and saturated fat ingestion on glucose-stimulated insulin secretion, sensitivity and clearance in overweight and obese, non-diabetic humans

Over a 24h period the ingestion of safflower oil, with linoleic acid providing in the region of 70% of total calories, ought to demonstrate the initial Protons predicted insulin sensitising effect, which would only be later replaced by the uncoupling effect if the study had been continued for a week or two. 

Again we can assess insulin sensitivity by how much glucose was needed to be infused during the last 30 minutes of the clamp to maintain an hyperglycaemia of 20mmol/l. This is what happens:

I don't think I have to make any qualifications here. SFA oral ingestion for 24h causes a very similar degree of insulin resistance to oral ingestion of a minimal calorie supplying control chocolate drink. Tallow rather than palm oil would have accentuated the effect.

Ingesting 70% of your calories as linoleic acid over a 24h period is insulin sensitising compared to ingesting SFA, p less than 0.001. Or ingesting virtually nothing at all, p < 0.05.

Linoelic acid is insulin sensitising.

This is BAD. When fasting you *must* resist even basal insulin or that insulin will lower fasting glucose, lower fasting FFAs and you will be hungry. And raid the fridge at 2am. And get fat.

Protons.

Peter