Healthy Diets

Well, we got through the holiday season. Mostly. A new year is upon us, and this is the time when many people evaluate their diets, looking for something better.

When you have diabetes, you'll get advice from all sorts of dietary experts, some of them telling you to eat lots of carbohydrate and very little fat and others telling you the exact opposite, to eat very little carbohydrate and not worry about the fat. Others will propose something in between.

Even within diet groups the opinions differ. Some proponents of low-carb diets say you can eat any kind of fat you want as long as you severely curtail your intake of carbs (for example, the original Atkins diet, which was heavy on rib roasts and sour cream). Others tell you to limit the saturated fat and concentrate on monounsaturated fat instead (for example, the Four Corners diet, which I coauthored). And others want you to focus on getting enough protein so you won't break down your muscle tissue (for example, the Protein Power diet of the Eadeses).

There are so many studies of diets that you can pretty much find a study to back up any theory you have. And the definition of "low carb" or "low fat" may differ from study to study. So one study might conclude that "low carb" diets (with 140 g of carbs a day) did one thing whereas another study might conclude that "low carb" diets (with 50 g of carbs a day) did something quite different.

If you were following a recommended 60% carbohydrate diet with 2000 calories a day, that would work out to 300 grams of carbs a day. Compared with this, a diet with 150 g of carbs would be considered "low carb." Another group might test a really low carb diet of 50 g a day vs a "high carb" diet of 150 g a day. That would mean that in one test the same level of carbohydrate would be labeled "high carb" in one study and "low carb" in another.

Most people don't notice these discrepancies when they read diet studies in the popular press (which often omits such details) or even when they read the entire papers. So it's easy to cite the study that supports the conclusion you believe in.

The same problem affects the use of the word "healthy." You could eat what I would consider a pretty healthy low-fat diet, and you could also eat what I consider a pretty unhealthy low-fat diet. The same applies to low-carb diets. (I'm using the two extremes here to make a point.) For example, here are two menus in what I'd consider both unhealthy and healthy versions of the low-fat and low-carb diets (alas, a tad difficult to read because of the way the table is uploaded).

Although I haven't put these menus into a nutritional program, so they might differ in caloric content, I think they'd all be considered appropriate by people on a low-fat or a low-carb diet. If you compared the unhealthier diets at the left, you'd most likely see big differences in various metabolic parameters, including postprandial blood glucose (BG) levels and postprandial lipid levels.