Grains have been part of the human diet for thousands of years. In the early days of agriculture, humans ate whole grains like barley and maize practically straight from the stalk. Rich in fiber and nutrients such as B vitamins, phosphorus and magnesium, these hardly-processed grains gave humans high powered packets of healthful calories to propel them through their ever-mobile lifestyle.

Flash forward 14 thousand years (give or take) and Americans are mired in a processed food culture. Kernels formerly chock-full with goodness now get crushed into dust and mixed up again into our loaves of bread and burger buns.

The processing systems developed over the last 150 years strip grains of both their nutrient-loaded outermost layer, called the bran, and the germ (the part that would eventually grow into a new plant)— revealing and powdering the endosperm, which contains the grain’s starch. Since the digestive system no longer has to break through the bran’s barrier to get to the starchy interior, processed grains are like a hit of carbs straight to the system, spiking blood glucose faster than their intact counterparts, leading to a quicker crash and the desire to eat more frequently.

The bran and germ contain the majority of a grain’s nutrients and fiber. Fiber isn’t digested, so doesn’t affect blood glucose or contribute calories. The different types of fiber, soluble and insoluble, provide a host of benefits including lowering blood cholesterol levels and preventing constipation. Fiber makes you feel fuller longer, since it takes a while to work its way through your digestive system. This continued satiety can help you lose weight, since you won’t feel hungry as frequently.

Health benefits of whole grains (reduced risk of heart disease, type 2 diabetes, obesity, and some types of cancer to name a few) have been realized over the past few years, leading more companies to put out “whole” versions of their products. However, ingredient lists and packaging claims can be deceiving. The FDA says that companies can list their product as whole grain as long as all three parts, the bran, germ, and endosperm, all make an appearance—but they don’t necessarily have to be one unit. If the three constituents were first separated then mixed all together again the product can be labeled as being whole grain.

But here’s the problem—the bran, no longer encasing the endosperm, doesn’t protect from the rapid digestion of the carbs found inside the grain. Sure, the reintroduction of the bran and germ bring back the formerly cast aside nutrients and fiber, but there’s nothing slowing down the absorption of the glucose-spiking carbohydrate. It’s better than purely processed, endosperm-only white bread, but still not as good as “whole” whole grains. That’s why steel cut oats, the kind that need to be cooked for a half an hour before becoming edible, are much better for blood glucose levels than the more processed sort-of “whole grain” of instant oatmeal.

So how do you decide which grains are whole grains when browsing the supermarket shelves? There are a couple of options.

You could consult the glycemic index (GI) scale before you head to the market. The GI scale measures how quickly a food raises blood glucose levels. Whole grain products that register lower on that scale are probably whole in the truer sense of the word. (But keep in mind, other things affect the GI of a food product, so just because a bread is low-GI doesn’t mean it’s whole grain.)

You can also look to the label—check for foods that list a whole grain (brown rice, whole oats, cracked wheat are some examples) as a first ingredient. Even though they might not be completely intact, some whole grain is better than none. And these pseudo-whole grains aren’t necessarily bad for you—they just aren’t as good.

What might be the best way to identify products containing the wholest of whole grains comes from recent research stating that for every 10 grams of carbohydrate listed on the food label there should also be at least one gram of fiber. “Foods that met the 10:1 ratio tended to have less sugar, sodium and trans fats than those that didn’t,” according to a recent Chicago Tribune article.

To reap the health benefits, aim for at least 3 servings of whole grains per day. One serving is an ounce, equal to one slice of bread, one cup of cereal or one half a cup of cooked rice or pasta. When making your meals, one quarter of your plate should be filled with healthy, unrefined carb food (alongside half a plate of vegetables and a quarter plate of lean protein).

Some examples of whole grain foods are barley, quinoa, and brown rice. You can find lots of recipes online that make these whole grains delicious. And use whole wheat flour when baking—modify your favorite recipes by replacing half the flour called for with whole wheat.

Other ways to fit whole grains into your eating plan include:

Choosing whole grain breads, bagels, English muffins
Whole wheat pasta instead of white pasta
Choose a whole grain cereal
Try popcorn (minus the butter and salt) as a snack…

Whole grains can be an acquired taste, so ease yourself into it.

As with all foods, amount and types of nutrients varies in different whole grains. Most, but not all, whole grains have at least 2 to 3 grams of fiber per serving (daily fiber recommendations for adults come in between 20 to 35 grams per day).

Check out this Harvard School of Public Health article for more details on the health benefits of eating whole grain foods. Make sure you check your blood glucose with your meter after trying new foods to see how they affects your levels, so you can healthfully incorporate them into your meal plan.

This post first appeared on Speaking of Diabetes

in April 2013