Peter: I still haven't answered your question which is, "How do you do this with diet?" But...

Rhonda: Well...

Peter: So I will explain conceptually how you do it. How you do it at the individual level is empirical and I think prescriptive, meaning you have to be able to try something, iterate on it, and make a measurement. But here's the conceptual way to do it. The conceptual way to do it, at least the way I do it, is you consume more or less the least amount of protein you can consume to maintain and grow muscle mass. But you don't need any more than that. So it depends on the individual, it depends on the timing of that protein ingestion, the quality of that protein and the type of metabolic and conditioning stimulus you put into it, but there's an amount. But for most of us I think we're probably over consuming protein relative to that actual need, so we raise protein level until we hit that amount.

Carbohydrate, we do the opposite. Carbohydrate, we are basically lowering it until we reach the highest point...or pardon me, the lowest point that we can tolerate where we can maintain, and again, this is quick and dirty but it's the lowest possible fasting insulin. And in my mind I typically like to see that at below 3 or 4 as IU of insulin. And you want to limit, sort of, post-meal glycemia. And I actually use a standardized test which is an OGTT which has its limits because it's liquid, you're drinking liquid glucose. I like to limit that postprandial hyperinsulinemia to a number and I use a checkpoint of 30 that I want to be able to see within one hour of a 75-gram glucose challenge if you can keep insulin below 30.

So in my mind, because I can't do what's called an AUC, an area under the curve. So the really rigorous way to do this would be I'd put a catheter in your arm and I would sample your blood every 30 or 60 minutes over the course of a day while you ate. And I'd integrate that function and there would be an area under the curve of insulin, and that's actually the number I care about. But since I can't do that outside of a research setting, I rely on these other proxies. So the bottom line is your carbohydrate content is highly variable by the individual, by their insulin sensitivity, by their muscle mass and their capacity to dispose of glucose and a host of other factors. But the bottom line is you don't want to consume any more carbohydrate than you can without blowing through those parameters, and you don't want to consume any more protein than you need to to preserve that. And then basically, fat becomes the fill.

And so the point here is that that becomes a highly different diet for different people. For some people that's 40% carbohydrate and 20% protein, and the remainder of fat. For others that's 20% carbohydrate and 15% protein and the remainder of fat.