What Your Doctor Doesn't Tell You About Fats and Carbs

If you recently have been diagnosed with type 2 diabetes, chances are your nutritional advice has fallen into one of two mutually exclusive categories:

1. Eat fewer carbs. Your body turns almost all carbohydrates into glucose either quickly or slowly, so to get your blood sugar levels down, eat less carbohydrate.
2. Eat more carbs. You have diabetes because you are overfat, so replace the fat in your diet with carbohydrate.

It's enough to make you wonder if doctors and nutritionists really know how to treat diabetes, but there is, despite what you may hear from true believers in one kind of diabetes diet or another, value in both approaches.

The idea that diabetics should eat less carbohydrate makes inherent sense. Diabetes is a condition in which either the body is not making enough insulin or insulin does not work effectively. If you are not going to inject insulin or take drugs that sensitize cells to insulin or use medications that force the pancreas to produce more insulin, it makes sense to give your insulin less to do.

In type 2 diabetes, at least in the earlier stages, the body can produce insulin slowly, but not fast enough to take care of a "dump" of carbohydrate from a high-carb meal. For these diabetics, it makes sense to eat a different kind of carbohydrate, the more slowly digested carbohydrates associated with low-glycemic index foods like whole grains and vegetables. Even whole grains and vegetables, however, add up, and there are no "freebies." Too many turnips can raise blood sugars as much as too much cake, only much more slowly.

But what if you ate almost no carbohydrate at all? Wouldn't this be even better for getting blood sugars down?

There is a growing number of doctors and diabetics finding success with diets that allow 1/10 to 1/5 as much carbohydrate as suggested by the American Diabetes Association. The body still needs insulin to move glucose into cells, because about 23 per cent of the amino acids in high-protein foods are eventually transformed into sugar. The body does not need as much glucose, and blood sugars do not swing up and down as they do on high-carb diets, even "good carb" diets. And fats do not turn into blood sugar.

The problem comes when diabetics try to mix the two approaches, eating both high-fat and high-carb, or alternating high-fat and high-carb. If you eat a meal that's mostly carbohydrate, the liver will sense raising blood sugar levels and stop converting its stores of glycogen into even more glucose. If you eat a meal that is high in both fat and carbohydrate, the liver will not sense the load of glucose and stop releasing sugar. This is because the liver is "blinded" to glucose levels by the fatty acids released in the digestion of fatty foods.

A high-fat meal can cause excess production of glucose by the liver for as long as seventy-two hours. And in those seventy-two hours, elevated levels of sugar in the bloodstream can "turn off" muscle cells in ways that make them less sensitive to insulin the next time the diabetic eats any kind of meal, either high-carb or high-fat.

This principle is why both vegan raw foods diets and Atkins-style diets work for getting blood sugars down, provided any food that is consumed is consumed in moderation. The good news is, diabetics who manage to keep both blood sugar and blood fatty acids low for 72 hours begin to repair insulin sensitivity, sometimes to the level of people who do not have diabetes, whichever approach they use.

References:

Hawkins M, Gabriely I, Wozniak R, Mevorach M, Rossetti L, Shamoon H: The effect of glycemic control on hepatic and peripheral glucose effectiveness in type 2 diabetes mellitus. Diabetes 51:2179–2189, 2002.