Take away notes:
MPS is elevated for 24-48 hours so no, it's really not that important for most.
Glycemic index has no real relevance with the possible exception of diabetics, and then in the context of a varied diet likely makes little to no difference.
Also you have to take into account whether or not someone has eaten anything during the day, digestion and absorption takes time and most are in a post prandial state while working out so substrates are being absorbed throughout the day. If you are training fasted then maybe, but again everyone will be eating within a few hours and that is sufficient for intermediate lifters.
You should check out AA's sticky above that addresses post workout meals. What's most important is total daily intake, and unless training fasted, ingesting protein/carbs post workout makes little difference with the only potential exception being the highly elite BBd'er. Training and diet needn't be so restrictive.
FYI, gluconeogenesis is the synthesis of glucose from any carbon substrate other than carbohydrate substrates. In order for insulin to be secreted biphasically, as it does with carbohydrates, glucose must be detected in the blood. In a meal containing only protein, like we are describing, glucose from this meal won't get into the blood until gluconeogenesis occurs to synthesize glucose from the amino acids that are broken down from the protein source. The rate at which gluconeogenesis converts amino acids to glucose is comparatively a very small amount to the rate at which glycolysis breaks down carbohydrates into glucose, ultimately only causing a very small insulin response from any protein source. Now, there are amino acids that cause an insulin response before they can be converted into glucose... Although the insulin response from amino acids is monophasic, so the pancreas does not produce a secondary insulin response as it does with glucose, which is comparitively the larger release. So no, the insulin response from a protein source is not similar at all to the insulin response to "high GI" carbohydrates. Completely different in fact.
Alan Aragon:
Hierarchy of Importance
When speaking of nutrition for improving body composition or training performance, it's crucial to realize there's an underlying hierarchy of importance. At the top of the hierarchy is total amount of the macronutrients by the end of the day. Distantly below that is the precise timing of those nutrients. With very few exceptions, athletes and active individuals eat multiple times per day. Thus, the majority of their day is spent in the postprandial (fed) rather than a post-absorptive (fasted) state. The vast majority of nutrient timing studies have been done on overnight-fasted subjects put through glycogen depletion protocols, which obviously limits the applicability of the outcomes. Pre-exercise (and/or during-exercise) nutrient intake often has a lingering carry-over effect into the post-exercise period. Throughout the day, there's a constant overlap of meal digestion & nutrient absorption. For this reason, the effectiveness of nutrient timing does not require a high degree of precision.
The Primary Laws of Nutrient Timing
The First Law of Nutrient Timing is: hitting your daily macronutrient targets is FAR more important than nutrient timing.
The Second Law of Nutrient Timing is: hitting your daily macronutrient targets is FAR more important than nutrient timing.
NOTE: Please do not misinterpret the above to mean that timing is irrelevant. On the contrary, it's very relevant. Timing just happens to have MUCH LESS impact on results than hitting your macro totals for the day. This doesn't diminish the fact that people need to individualize their meal timing so that it maximizes their training performance (& does not hinder it). The latter manipulations vary widely, because people have different training protocols, goals, and tolerances. For example, some people experience their best training performance in an immediately fed state, while others do best in a semi-fasted or fasted state. Endurance athletes who neglect carbohydrate timing will not optimize their training capacity. Strength/power athletes with minimal endurance demands have much less of a concern for this. There's no way to 'universalize' a nutrient timing prescription that applies to everyone & all types of athletes. But to reiterate, macro totals for the day overshadow timing in terms of importance, especially for bodybuilding. If macro totals for the day are not hit, the most precisely neurotic timing of meals is all for sh!t.
http://www.jissn.com/content/10/1/5
http://www.jissn.com/content/pdf/1550-2783-10-5.pdf
"The postexercise "anabolic window" is a highly misused & abused concept. Preworkout nutrition all but cancels the urgency, unless you're an endurance athlete with multiple glycogen-depleting events in a single day. Getting down to brass tacks, a relatively recent study (Power et al. 2009) showed that a 45g dose of whey protein isolate takes appx 50 minutes to cause blood AA levels to peak. Resulting insulin levels, which peaked at 40 minutes after ingestion, remained at elevations known to max out the inhibition of muscle protein breakdown (15-30 mU/L) for 120 minutes after ingestion. This dose takes 3 hours for insulin & AA levels to return to baseline from the point of ingestion. The inclusion of carbs to this dose would cause AA & insulin levels to peak higher & stay elevated above baseline even longer.
So much for the anabolic peephole & the urgency to down AAs during your weight training workout; they are already seeping into circulation (& will continue to do so after your training bout is done). Even in the event that a preworkout meal is skipped, the anabolic effect of the postworkout meal is increased as a supercompensatory response (Deldicque et al, 2010). Moving on, another recent study (Staples et al, 2010) found that a substantial dose of carbohydrate (50g maltodextrin) added to 25g whey protein was unable to further increase postexercise net muscle protein balance compared to the protein dose without carbs. Again, this is not to say that adding carbs at this point is counterproductive, but it certainly doesn't support the idea that you must get your lightning-fast postexercise carb orgy for optimal results.
To add to this... Why has the majority of longer-term research failed to show any meaningful differences in nutrient timing relative to the resistance training bout? It's likely because the body is smarter than we give it credit for. Most people don't know that as a result of a single training bout, the receptivity of muscle to protein dosing can persist for at least 24 hours:
http://www.ncbi.nlm.nih.gov/pubmed/21289204
More from earlier in the thread:
Here's what you're not seeming to grasp: the "windows" for taking advantage of nutrient timing are not little peepholes. They're more like bay windows of a mansion. You're ignoring just how long the anabolic effects are of a typical mixed meal. Depending on the size of a meal, it takes a good 1-2 hours for circulating substrate levels to peak, and it takes a good 3-6 hours (or more) for everythng to drop back down to baseline.
You're also ignoring the fact that the anabolic effects of a meal are maxed out at much lower levels than typical meals drive insulin & amino acids up to. Furthermore, you're also ignoring the body's ability of anabolic (& fat-oxidative) supercompensation when forced to work in the absence of fuels. So, metaphorically speaking, our physiology basically has the universe mapped out and you're thinking it needs to be taught addition & subtraction."