The Laws of Small Numbers
Many years ago, John Galloway, then medical director of Eli Lilly and Company, performed an eye-opening experiment. He gave one injection of 70 units of regular insulin (a very large dose) to a nondiabetic volunteer who was connected to an intravenous glucose infusion.
Dr. Galloway then measured blood sugars every few minutes and adjusted the glucose drip to keep the patient’s blood sugars clamped at 90 mg/dl. How long would you guess the glucose infusion had to be continued to prevent dangerously low blood sugars, or hypoglycemia?
It took a week, even though the package insert says that regular insulin lasts only 4–12 hours. So the conclusion is that even the timing of injected insulin is very much dependent upon how much was injected. In practice, larger insulin injections start working sooner, last longer, and have less predictable timing.
If you eat a meal not specifically tailored to our restricted-carbohydrate diet and try to cover it with insulin, you’ll get a postprandial (after-eating) increase in blood sugar, eventually followed by a decrease as the fast-acting insulin catches up. This means that you’ll have high blood sugars after every meal, and you could still fall prey to the long-term complications of diabetes. If you try to prevent the inevitable postprandial blood sugar spike by waiting to eat until after the start time of your insulin, you may easily make yourself hypoglycemic, which could in turn cause you to overcompensate by overeating— that is, presuming you don’t lose consciousness first.
Type 2 diabetics have a diminished or absent phase I insulin response, and so they face a problem similar to that of type 1s. They have to wait hours for the phase II insulin to catch up if they eat fast-acting carbohydrate or large amounts of slow-acting carbohydrate.
The key to timing insulin injections is to know how carbohydrates and insulin affect your blood sugar and to use that knowledge to minimize the swings. Since you can’t approximate phase I insulin response, you have to eat foods that allow you to work within the limits of the insulin you make or inject. If you think you’ll miss out on the great high-carbohydrate, low-fat diet recommended by the ADA— which, if you look at the statistics, has only succeeded in raising levels of obesity, elevating triglycerides and LDL, and causing an epidemic of diabetes—there is considerable evidence that restricting carbohydrate is healthier not only for diabetics but for everyone. (For more details on this point, see Protein Power, by Drs.Michael and Mary Dan Eades, Bantam Books, 1996; or go to www.diabetes-book.com and, under “Articles,” read “What If It’s All Been a Big Fat Lie?” by Gary Taubes.)
If you consume only small amounts of slow-acting carbohydrate, you can actually prevent postprandial blood sugar elevation with injected preprandial rapid-acting insulin. In fact, by restricting carbohydrate intake, many type 2 diabetics will be able to prevent this rise with their phase II insulin response and will not need injected insulin before meals.
OBEYING THE LAWS OF SMALL NUMBERS
Essential to obeying the Laws of Small Numbers is to eat only small amounts of slow-acting carbohydrate when you eat carbohydrate, and no fast-acting carbohydrate. Even the slowest-acting carbohydrate can outpace injected or phase II insulin if consumed in greater amounts than recommended later in this book (Chapters 9–11).
If you eat a small amount of slow-acting carbohydrate, you might get by with a very small or no postprandial blood sugar increase. If you double the amount of slow-acting carbohydrate, you’ll more than double the potential increase in blood sugar (and remember that high blood sugar leads to even higher blood sugar). If you fill up on slowacting carbohydrate, it will work as fast as a lesser amount of fast-acting carbohydrate, and if you feel stuffed, you’ll compound it with the Chinese restaurant effect.
All of this not only points toward eating less carbohydrate, it also implies eating smaller meals 4 or 5 times a day rather than three large meals. If you’re a type 2 diabetic and require no medication, eating like this may work well for you. The difficulty with this sort of plan is its inconvenience, but some people don’t mind and actually prefer to eat this way. One of my patients, a type 1 diabetic who still makes some insulin, eats a couple of bites of protein every 20 minutes and takes long-acting insulin. In a 16-hour day, that adds up to a lot of minimeals and a lot of clock-watching. This routine would drive many people nuts, but it almost works for her. As long as she keeps up with her frequent little meals and covers the insulin, she’s fine. When she misses a few “meals,” there inevitably is trouble.
For the type 2 diabetic who doesn’t need insulin injections, smaller meals throughout the day can be a very effective way of maintaining a constant level of blood sugar. Since this kind of diet would be tailored to work with a phase II insulin response, blood sugars should never go too high. It would, however, involve a certain amount of daily preparation and routinization that could be thrown off by changes in schedule— illness, travel, houseguests, and so forth. People who cover their meals with injected insulin and also correct small blood sugar elevations with very rapid acting insulin, however, cannot get away with more than three daily meals (Chapter 19).