Evidence in the nutritional literature shows an association between low quality foods and the risk of Western lifestyle disease. In particular, refined and processed cereal grains and crystalline sugar are thought to significantly increase the risk of obesity, type 2 diabetes and cardiovascular disease. Many individuals overestimate the quality of their diet because they have been lead to believe that the foods they eat as part of their Western diet are healthy. However, many Western foods that are perceived to be healthy are no better than convenience snack foods such as chocolate bars and other sugar laden foods. The reason for this is based on the glycaemic index (GI) of these foods being of similar magnitude due to the processed nature of the carbohydrates. For example, white bread is rated on the glycaemic index at the same value as crystalline glucose, and is devoid of any meaningful levels of micronutrients or fibre. Consumption of white bread is therefore detrimental to the health, despite being a primary part of many Western eating plans.
Researchers have compared the glycaemic responses of common snack foods with commonly eaten foods from the Western diet and found little difference in postprandial glycaemic response. For example in one study1, the glycaemic response of healthy male subjects to a variety of snacks (milk chocolate bar, glucose solution, granola bar, chocolate milk, peanut butter snack, crisps and yoghurt) and non-snack foods (cereal with milk, cheese sandwich with milk, peanut butter sandwich and milk) were assessed using a crossover design study. All foods contained 25 grams carbohydrate with between 133 to 268 kcal. The snack foods produced a lower glycaemic response compared to a glucose solution, with 60 min values falling below baseline, suggesting hypoglycaemia had developed. While the glycaemic responses to the snack foods were similar, the insulin responses were more complex. Here the yoghurt, chocolate bar and chocolate milk produced similar values to the glucose solution, while the crisp snack produced the lowest values.
When the researchers tested the non-snack foods, they found little difference in terms of postprandial glucose or insulin response compared to the snacks. Therefore commonly eaten staple foods in the Western diet, that many assume to be healthy, produce similar detrimental glycaemic effects to convenience snack foods. The cereal and bread in this study were refined and processed foods, which means that they would have been devoid of fibre and essential micronutrients. As well as providing little nutritional value, the lack of fibre may deleteriously affect the glycaemic index when compared to whole grain alternatives. Traditional diets do not contain refined carbohydrates, and those who adhere to them do not develop Western lifestyle diseases. Substituting whole grain cereals for refined cereal grains has been shown to improve health because they produce a more beneficial glucose response. Foods such as white bread, refined breakfast cereal and foods with added sugar are in reality no better than common snack foods.
