Metabolic Syndrome in Normal Weight Individuals

The metabolic syndrome is a cluster of metabolic disorders that develop due to an underlying insulin resistant state. As insulin sensitivity declines, blood sugar levels rise and insulin production increases in response to ingested carbohydrate ingestion. Such a hyperglycaemic hyperinsulinaemic state then leads to a plethora of detrimental metabolic changes that includes modifications to lipoprotein homeostasis and energy regulation. In addition, oxidative stress increases systemically and this induces an inflammatory state that can drive the development of diseases such as cancer and cardiovascular disease. The metabolic syndrome is associated with weight gain, because hyperglycaemia and hyperinsulinaemia are conductive of body fat storage and a general anabolic state. Further, the changes that occur in the liver as a result of developing metabolic syndrome cause fatty acid accumulation in the liver and surrounding organs leading to abdominal obesity and the development of nonalcoholic fatty liver disease (NAFLD).

Although the metabolic syndrome is associated with weight gain, evidence suggests that normal weight individuals can also develop the disorder. This paradoxically situation comes about because although insulin resistance can lead to weight gain, this is not always the case. Normal weight individuals can develop insulin resistance and hyperinsulinaemia, and with it many of the metabolic aberrations that result from such a state. Clinical measurements show that normal weight individuals can develop high blood pressure, hyperinsulinemia, non-alcoholic fatty liver disease, lipoprotein dysfunction, hyperglycaemia, hypertriglyceridemia, type 2 diabetes and cardiovascular disease, and as such could be said to have metabolic syndrome. Such individuals may appear to be of normal weight when clothed, and may also possess body mass indexes that do not place them in overweight categories. However, medical examination would reveal a degree of adiposity around the waist which is indicative of the insulin resistant state.

The metabolic syndrome has a complex aetiology. However, increasingly it is being shown that poor quality foods are the driver of the insulin resistance that underlies the disorder. In particular, the typical Western diet is implicated as a primary causative factor in the development of the metabolic syndrome due to its high content of refined carbohydrates and its low content of fibre, essential micronutrients and essential fatty acids. Observational studies and clinical trials investigating the effects of high quality traditional diets show that they can reverse both the underlying insulin resistance and the associated metabolic changes that occur following a long period of poor quality nutrition. Normal weight metabolically dysfunctional individuals would therefore benefit from the same switch to a high quality diet as those obese metabolically dysfunctional individuals because the insulin resistance that characterises the health of both groups, responds to dietary manipulation.

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Ruderman, N. B., Schneider, S. H. and Berchtold, P. 1981. The “metabolically-obese,” normal-weight individual. American Journal of Clinical Nutrition. 34(8): 1617-1621

About Robert Barrington

Robert Barrington is a writer, nutritionist, lecturer and philosopher.
This entry was posted in Abdominal Obesity, Adipose Tissue, Glycaemia, Insulin Resistance, Metabolic Syndrome, Obesity, Western Diet. Bookmark the permalink.