My gut feel (...) is that not controlling for time per unit of mass consumed invalidates the result, as hormonal signals are slow.

IE, 25g per minute chewed 15 times vs 25g per minute chewed 40 times.

This would be highly dependant on the type of food. Bread (and pizza) chunks break down well in the gut, in comparison to mushrooms that hardly break down at all after chewing.

Insulin is released in response to blood sugar. Guesswork extrapolation : Chewing more increases surface area increasing the speed of digestion. I am not sure how chewing interacts with the amount of overall time food spends in the gut.

Still very interesting work. I would love to see an analysis of stomach acid production in relation to chewing cycles.

Of note, and correct me if I am wrong, but isn't n30 the minimum for statistical significance? (even though n30 is still laughably low, and id prefer n3000)