|Image 1: Firstly, obesity is not the only determinant of metabolic derangement. And secondly, if your diet does not match your Metabotype, it's unlikely you'll ever make it from the left to the right (img. DrPinna.com)|
You know your phenotype, but what's your metabotype?
The main intention of the study, which involved 24 healthy, non-obese pre-menopausal women (20-50y), was to identify distinct metabotypes within the healthy population, in order to develop a better understanding of the (in some cases) fundamental inter-individual differences to identical carbohydrate challenges. To this ends the study participants had to consume a standardized 3-day run-in diet (56% carbs, 14% protein, 30% fat; same as test meal) before consuming a standardized high (GI 76.7; GL: 86.3; 833kcal) or low GI (GI: 36.5; GL: 42.1; 835kcal) breakfast after an overnight fast.
|Figure 1: Body composition and non-esterified fatty acid levels of the women in the different response groups (RG1-3) the scientists identified in statistical ex-post analyses (data adapted from Krishnan. 2012)|
Insulin or leptin resistance? Devil or deep blue sea?
The principal component analysis (PCA) the scientists conducted revealed that, when compared to the normal-responders in RG1, ...
- the women in group RG2 had lower postprandial leptin, higher insulin and higher glucose relative
responses to the two meal challenges (cf. figure 2),
- the women in group RG3, on the other hand, had a higher leptin and glucose, yet similar insulin responses.
|Figure 2: Glucose, insulin and leptin (AUC, range scaled for high & low GI meals) in the of the women in the different response groups (RG1-3) the scientists identified in statistical ex-post analyses (data adapted from Krishnan. 2012)|
6 outliers in 24 sounds less than 25% of the population, right?
|Image 2: If you invite 5 friends for lunch, one person at the table will handle the carbohydrate content of the meal differently|
- the subjects were exclusively premenopausal women
- only three subjects in the "non fine-tuned" groups,
- no mechanistic explanation for the observations,
- possible influence of the run-in diet,
- only a single challenge with each of the test meals
And what's more, if it was recognized as such by the medical establishment (in this context it should be mentioned that co-author John W. Newman works at the Western Human Nutrition Research Center, Obesity and Metabolism Research Unit of the USDA) study was conducted by scientists from the USDA) it would open a door to a differential and thusly way more effective treatment diet-related disease. And, at least according to the data from the study at hand, for 25% of the normal-weight, ostensibly healthy part of the (female) population, this would not be the currently advocated high-carb, low-fat diet