Should you follow a no-grain diet?

The No-Grain diet is based on the idea that grains and sugars are "enemy number one to losing weight and living longer."

Instead, The No-Grain diet emphasizes organic vegetables and quality protein.

It's true that refined grains — such as white bread, white rice and many breakfast cereals — contain many calories, but without the fiber, vitamins, and minerals found in whole-grains.

In other words, they're energy-dense but nutrient-sparse.

But it's worth pointing out that there's a difference between whole grains and refined grains.

A good example comes from a study published in the American Journal of Clinical Nutrition [1]. The results show that middle-aged women who favor whole grains over white bread and other refined grains put on fewer pounds as they age.

Harvard researchers found that among 74,000 women, those who ate more fiber-rich grains — such as oatmeal and whole-grain breakfast cereals — gained less weight over time than women who got the least fiber in their diets.

In addition, women with the highest fiber intake were half as likely as those with the lowest intake to become obese over 12 years. In contrast, diets heavy in refined-grain products like white bread and pasta were linked to greater weight gain over time.

While carbohydrates have lately gotten a bad rap in the weight-loss realm, the new findings underscores the fact that not all carbs are alike.

Research suggests that when it comes to weight control, whole grains such as oats, bran and brown rice have an advantage over highly processed, low-fiber grain products. For one, fiber-rich whole grains are more filling, and people who favor them over refined grains may take in fewer calories.

While starchy refined grains cause a rapid increase in blood sugar, whole grains may create a slower, more sustained release of sugar into the blood — which may have a beneficial effect on metabolism and fat storage.

Whole grains also contain enzyme inhibitors that may get in the way of metabolic efficiency. This means that your body is forced to burn extra calories just to digest and absorb whole-grain foods.

For their study, the researchers analyzed data from a large, long-running study of female nurses in the U.S. More than 74,000 women who were between the ages of 38 and 63 in 1984 periodically gave information on their diets and weight over the next 12 years. Other factors, such as exercise and alcohol intake, were also measured.

Women who ate more whole grains tended to weigh less than those with diets heavier in refined grains. And over time, higher intake of fiber-rich grains was associated with less weight gain.

On average, women who ate the most high-fiber, whole-grain foods gained a few pounds less than those with the lowest fiber intake. They were also less likely to become obese.

Diabetes

Eating whole grain food is also linked to a reduced risk of developing diabetes [3].

Nicola McKeown and colleagues from several US-based medical and academic establishments in Boston, Massachusetts and Charleston, South Carolina collected data from 2,834 subjects in the Framingham Offspring Cohort, part of the long-running Framingham Heart Study.

The aim was to examine the relationship between carbohydrate-related dietary factors, insulin and the prevalence of metabolic syndrome.

After adjusting for confounding variables, the results suggested that intakes of total dietary fibre, cereal fibre, fruit fibre and whole grains were inversely associated with insulin resistance.

In contrast, glycemic index and glycemic load were positively associated with insulin resistance (measured as the homeostasis model assessment of insulin resistance HOMA-IR).

The prevalence of metabolic syndrome was significantly lower in subjects whose intakes of cereal fibre and whole grains were in the highest quintile, relative to those with intakes in the lowest quintile.

Metabolic syndrome is characterised by a group of metabolic risk factors which are known to be closely associated with the development of type II diabetes and coronary heart disease.

One of the benefits of whole grains is that they contain important vitamins and minerals.

Magnesium is just one example.

A research team from the Harvard School of Public Health in Boston followed the fortunes of 85,060 women and 42,872 men who had no history of diabetes, cardiovascular disease or cancer at baseline [2].

Magnesium intake was estimated using food frequency questionnaires every 2-4 years over follow-up periods of 18 years for the women and 12 years for the men.

After adjusting for age, body mass index, smoking, alcohol consumption and other lifestyle factors, the data showed that men and women whose diets contained the highest amounts of magnesium (from whole grains, nuts and green leafy vegetables) were the least likely to develop type II diabetes.

A second study using data from 39,345 women in the Women’s Health Study at Brigham and Women’s Hospital and the Harvard Medical School in Boston, found that a high dietary intake of magnesium improved glucose and insulin homeostasis, and reduced the likelihood of developing type 2 diabetes, especially in overweight women [4].

Further evidence linking refined grains and weight gain comes from a Tufts University study. The research shows that regular consumption of white bread and other foods made from refined flour adds inches to the waistline.

Participants in the study who favored white bread actually gained a disproportionate amount of weight in the abdominal area.

The danger?

It's well established that abdominal fat is an independent risk factor for diabetes, which, of course, increases risk for many health problems.

The three-year study, published in the American Journal of Clinical Nutrition, tracked eating habits of 459 healthy people, both male and female, with an average age of 60 [5]. The purpose of the study: To see how the types of foods participants habitually ate impacted their waist circumference.

After analyzing the food-intake habits of the participants, the researchers determined that there were five basic dietary patterns. Members of the white-bread group (16% of daily calories from white flour) ate five times more refined flour products than members of the healthy group did... and gained three times what the healthy group did in the abdomen, expanding about one-half inch in the waist per year of the study.

According to the study's lead author, Dr. P. Kirsten Newby, the dominant feature of the study results was not that the healthy group ate a lot of whole-grain products. In fact, these accounted for just 1% of their total calorie intake. Rather, she says, it was that they ate such a limited amount of white bread and flour products.

Dr. Newby and her colleagues can only speculate about the reason white-flour consumption results in fat deposits in the abdomen, but what is certain is that white and refined flours have again been shown to be nonhealthful.

Grains come in many shapes and sizes, from large kernels of popcorn to small quinoa seeds. Grains, also called cereals, are the widely varied seeds of grasses, which are cultivated for food.

Grains are the seeds of plants. When whole, they include the bran, germ and endosperm — all of which contain beneficial nutrients.

• Bran. Forming the outer layer of the seed, the bran is a rich source of niacin, thiamin, riboflavin, magnesium, phosphorus, iron and zinc. The bran also contains the majority of the seed's fiber.

• Germ. The part from which a new plant sprouts, the germ is a concentrated source of niacin, thiamin, riboflavin, vitamin E, magnesium, phosphorus, iron and zinc. The germ also contains protein and some fat.

• Endosperm. Also called the kernel, the endosperm makes up the bulk of the seed. It contains most of the grain's protein and carbohydrates and has small amounts of vitamins and minerals.

Refined grains, such as white rice or white flour, have both the bran and germ removed from the grain. Although vitamins and minerals are added back into refined grains after the milling process, they still don't have as many nutrients as whole grains, and they don't provide the fiber.

Identifying whole grain products is not always that simple. It's easy to be deceived by breads labeled "nine-grain," "rye bread" or "made with whole grain."

Whole grain products should list a whole grain ingredient, such as "whole wheat," "whole rye," "whole-oats" as the first ingredient on the label.

They contain magnesium, vitamin E and some B vitamins, and are an excellent source of fiber, something Americans under consume. The good news is that there are a number of delicious and nutritious non-wheat grains available.

Gluten, the grain protein that gives dough its elasticity, frequently is the culprit behind wheat sensitivity. Many people may be wheat-gluten sensitive but not know it.

Dr. Judith Mabel, RD, PhD points out that hluten can cause digestive problems, such as constipation, and endocrine problems.

To underscore her point, she reminds people that when children make paste for gluing, it is composed of flour and water, which is not too different from the recipe for pasta and other wheat products. In addition to wheat, gluten is present in rye, barley, spelt, kamut, farina, triticale and, in the Western world, couscous. (In Africa, couscous is made with millet.)

References
1. Liu S, Willett WC, Manson JE, Hu FB, Rosner B, Colditz G. (2003). Relation between changes in intakes of dietary fiber and grain products and changes in weight and development of obesity among middle-aged women. American Journal of Clinical Nutrition, 78, 920-927
2. Lopez-Ridaura R, Willett WC, Rimm EB, Liu S, Stampfer MJ, Manson JE, Hu FB. (2004). Magnesium intake and risk of type 2 diabetes in men and women. Diabetes Care, 27, 134-140
3. McKeown NM, Meigs JB, Liu S, Saltzman E, Wilson PW, Jacques PF. (2004). Carbohydrate nutrition, insulin resistance, and the prevalence of the metabolic syndrome in the Framingham Offspring Cohort. Diabetes Care, 27, 538-546
4. Song Y, Manson JE, Buring JE, Liu S. (2004). Dietary magnesium intake in relation to plasma insulin levels and risk of type 2 diabetes in women. Diabetes Care, 27, 59-65
5. Newby PK, Muller D, Hallfrisch J, Andres R, Tucker KL. (2004). Food patterns measured by factor analysis and anthropometric changes in adults. American Journal of Clinical Nutrition, 80, 504-513