Monday, April 27, 2009

Pulse: Insulin basics

In the first part of this series I explained some take home points. These were:

1. Insulin levels must be low for fat loss to occur
2. Growth hormone must be released for fat loss to occur
3. Calories out must be greater than calories in.
4. fasting drops insulin levels, raises GH levels, and cuts calories.

All of these points lead to some interesting questions. I'll deal with the first of these today: controlling insulin levels.

First, though, what is insulin? From Taubes' Good Calories, Bad Calories
Insulin is the primary regulator of fat storage. When insulin levels are elevated—either chronically or after a meal—we accumulate fat in our fat tissue. When insulin levels fall, we release fat from our fat tissue and use it for fuel.

All food stimulates insulin release, but foods with sugar and/or starch (carbohydrate) release the most insulin.

Here's an excerpt from Taubes' book where he explains his basic ideas about nutrition or you can order his book here. You can also watch this video, but it's NSFW, since it includes shots of naked fat people. Taubes comes on about 2:40 if you're not interested in his bona fides.

So if insulin levels drive fat storage, how can we control insulin levels? There are three ways that I will consider here:

1. Eat small, frequent meals (SFM)
2. Eat a low carbohydrate (LC) diet of probably less than 10-15% but definitely less than 40% of energy
3. Fast intermittently (IF) for more than 12 but less than 48 hours

Let's talk about the "small frequent meals" theory. The idea here is that you can control your insulin levels by eating mini-meals of 100-500 calories, five to eight times a day. If you've read Body for Life or are a tupperware-toting bodybuilder, then you know all about this approach. The idea, as I understand it, is that you can keep things humming along, your blood sugar never dips, and you'll never get hungry if you just eat these small, frequent meals. The problem is that all eating has some insulin response. So eating five to eight times a day, even if they are small responses, creates insulin responses five to eight times a day. Even if Taubes wouldn't call this "chronically elevated" insulin levels, I think I would.

This also presents a couple of practical problems: if you have to eat five to eight times a day, this means you have to prepare five to eight meals a day: a tiny portion of meat, a tiny portion of carbohydrate, a tiny portion of vegetable. Five to eight of them. Welcome to the tupperware club, my friend. This is why supplement companies have hawked this plan for so long: not necessarily because it's more effective, but because preparing five to eight meals a day is such a pain in the ass, it's easier to eat a "meal replacement" shake--and if that stuff isn't processed food, I don't know what is.

The second practical problem with the SFM idea is ghrelin. If you've ever noticed that you get hungry at the same times every day, that's ghrelin in action. One of the effects is that you can basically train yourself to get hungry at specific times of day--we'll talk about this later, as it relates to intermittent fasting--but think about this for now, as it relates to SFM. If you eat these small, frequent meals at the same times every day, you are training yourself to get hungry five to eight times a day, and you're not eating enough calories to maintain your bodyweight, so the gherlin is just lurking in the background. So when you (inevitably) miss one of your five to eight meals a day, you get extremely hungry, and you go for whatever junk is nearby.

Ultimately, I can't recommend SFM as a solution for insulin management. That leaves us with two other options:

2. Eat a low carbohydrate (LC)diet of probably less than 10-15% but definitely less than 40% of energy
3. Fast intermittently (IF) for more than 12 but less than 48 hours

If you watched the video, you'll know that Taubes' solution is to use a LC diet to control insulin, and I think this is a good first step. I'll discuss my approach to LC diet later in the Pulse series.

The other option is to fast (not eat) intermittently for more than 12, but less than 48 hours. This isn't a complicated approach, but it definitely deserves its own post as well, because there are a lot of ways to screw this up.

The take-home points from today's post:

1. Insulin causes fat gain
2. Eating causes the body to release insulin
3. Eating carbohydrates (sugars and starches) causes a larger insulin response, and thus more fat gain

Stay tuned--the Pulse series is just getting warmed up.

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