Poster Topical Area: Energy and Macronutrient Metabolism
Location: Hall D
Poster Board Number: 422
Objectives: Nutritional research frequently involves the use of self-reported measures of food intake such as dietary recall and food frequency questionnaires which may be subject to participants' systematic errors. The objective of this study was to explore and examine the use of metabolomics as a less biased form of diet identification tool. The hypothesis explored by this study was that metabolite profiles in subjects will show specific and identifiable patterns between high fat (HF) and high carbohydrate (HC) diets. The objective of this study is to produce a concrete step toward using metabolomics as a form of unbiased dietary recall.
Methods: 24 metabolically healthy, lean subjects (12 male, 12 female) between the ages of 19-45 were recruited for this study. Subjects were weight stable and provided eucaloric diets through the study. A standard diet consisting of prepared foods with 15% protein/35% fat/50% carbohydrate was consumed followed by either a HF diet or HC for 21 days. Plasma was analyzed using LC/MS in a targeted manner.
Results: Variability 68 targeted metabolites decreased from baseline after eating standard diet evaluated using Levene's F-test. This variability increased after eating HF or HC for 2 days and then stabilized between 7 and 14 days. When looking at specific groups of metabolites, medium chain acylcarnitines (C6 – C16:1) and succinate were most differentiated between HC and HF as identified by T-test (p
Discussion: There was a clear convergence of blood plasma metabolites after 3 days of a standard diet. There was also a divergence of subjects in the first week of an experimental diet which then stabilizes somewhere between 7 and 14 days. This shows that the diet does have a profound and measurable effect on plasma metabolites. This indicates that the changes in plasma metabolites is fairly quick and stabilizes after a week.
It was found that HF subjects had elevated levels of medium chain acylcarnitines and lower levels of succinate and tyrosine after 2 and 7 days. The elevations in acylcarnitines would seem to indicate that a HF diet involves an increase in these short and medium chain fatty acids entering the mitochondria. In conclusion, it appears that there may be an identifiable metabolite pattern which is telling of a difference between a high fat and high carbohydrate diet.
University of Michigan
Ann Arbor, Michigan