i think insulin is a very important hormone for building muscle. This is not just my opinion but a fact. I also think that most healthy bodybuilders should be able to use insulin to its maximum ability without injecting themselves with it. Instead they could eat the majority of their carbs (all high glycemic) in 1 or 2 meals meals a day taken in as fast as they possibly can and supplemented soon afterwards with about 100 g of pure protein or breast meat. They could also drink a couple glasses of water after their meal. The reasons I think this is a much better method are countless, but the most important reason is that your body will become insulin resistant way too quickly if you keep poking yourself with it. If you eat your carbs all in one meal eaten as quick as possible you not only produce the most insulin possible rhythmically (as the body would naturally instead of all at once) But you also allow for an entire day to gain back your sensitivity to the slin. If you are on a bulking cycle with AAS which allows you to work out wayyy more and still build muscle, you might want to have at least 3 carb/protein meals a day. I still think it would be beneficial to eat those meals in the style I stated above to maximize insulin production.
Does the speed you eat the meal really matter? ABSOLUTELY. Try eating the meal half as fast as you can and noting the mental effects of the insulin. Then try eating it as fast as possible and note the incredible difference. I have nearly passed out from eating a box and a half of oreos and 75 - 100grams whey isolate in 10 minutes with a glass or 2 of water.
Applying this method of eating, I have been able to take in the same amount of calories as usual and gain weight AT LEAST 5 - 10 times faster than normal. I cannot believe my eyes when I look at the scale. So do not try to tell me that you cannot get your body to naturally produce enough insulin to gain the maximum amount of weight for optimal results.