Carbs – Think Quality First
Vaious macronutrient ratios have been proposed to be optimal for health throughout the course of history. Largely influenced by the work of Ancel Keys and others in the 1960s, high carbohydrate (CHO), low fat diets became thought of as the nutritional path to health and longevity. More recently, CHOs have been vilified for their role in the onset of metabolic disorders such as obesity and type-2 diabetes mellitus. Because not all CHOs are of the same quality, one should be more concerned with the quality of the CHOs than the ratio in which they are consumed relative to other macronutrients.
The quality of the carbohydrate being consumed is the most important consideration when constructing a nutrition plan. CHOs, without all of the components present in their whole form, will ultimately not have the same metabolic response in the body. A common mechanism for refining grains is removal of the bran, germ and endosperm, which appear to be critical components for the proper metabolism of CHO. When meals composed of refined carbohydrate (RCHO) are compared with meals composed of whole grains, the RCHO meals have repeatedly been shown to cause elevated levels of postprandial insulin and glucose. In addition to having this response when consumed alone, this has been shown to be true while consumed simultaneously with protein and fat and in those with and without existing insulin utilization issues.
The ingestion of high amounts of RCHO and the subsequent postprandial elevation of blood glucose and insulin is thought to be one of the major reasons for the increase in coronary heart disease, obesity and type-2 diabetes in America. Because modern day humans remain similar genetically to their ancestral hunter-gatherers (HG) much work has been done to compare the standard HG diet with modern day dietary habits. The HG population consumed primarily whole grains, with ~22-40% of their overall diet coming from CHO, whereas modern day Americans are estimated to gather 40% of their daily energy intake from RCHO sources alone. This discrepancy in the proportion of the diet composed of RCHO, rather than the ratio of all forms of CHO, appears to be at the route of the increase of the aforementioned chronic illnesses.
Before the advent of CHO refinement, with different HG populations consuming a wide variety of different macronutrient ratios, there was far less prevalence of nutrition related chronic diseases that we see in today’s society. When composing one’s ideal nutrition plan, the first consideration, as it pertains to CHO consumption, should be ensuring the consumption of whole grain CHO rather than RCHO.
References
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