Project
The metabolic effects of acute [14C]-carbohydrate ingestion in lean and obese individuals
The caloric value of carbohydrates and how they are being used in our bodies are important parameters in our daily nutrition. In the battle against overweight, it is of key to understand which nutrition contributes to what extent in caloric intake. The caloric intake is calculated based on the energy in covalent bonds and the assumption that all energy is absorbed and used by the body. However, this often overestimates the caloric value of a compound. Therefore the aim of this project is to assess the caloric intake of two carbohydrates, and investigate how they are used in the body.
Description
In this project, the contribution of glucose to energy intake and its metabolic routes in the body will be assessed. As a second sugar a low glycemic sweetener will be studied, to generate energetic and metabolic insights. For glucose, systemic metabolic profiles between lean and obese people will be compared, forearm glucose uptake (FGU) and non-esterified fatty acid (NEFA) balance will be assessed using the arterialized venous-deep venous (AV-V), and in addition, the effect of a low or high glycaemic diet will be studied in a lean population. The 14C label also serves as a flux biomarker, to monitor for example de novo lipogenesis, which is among the most studied pathways in NASH and NAFLD. In addition, we can quantify the conversion of glucose to fructose. With this unique approach we introduce a new standard in studying diet and health relationships, i.e. caloric assessments as well as metabolic fluxes.
Accelerator Mass Spectrometry provides a unique possibility to precisely monitor the fate of dietary ingredients, both in caloric value and in providing information on the turnover of the compound in its metabolic pathways. This requires the intake of radioactive food ingredients which makes them traceable. Via a mass balance approach, the caloric value can be calculated using clinical data on the excretion (urine and feces) and 14CO2 production (exhaled air). Specific metabolic pathways can be highlighted by quantifying 14C levels in various downstream products. Uptake in skeletal muscle can be quantified using forearm balance measurements. These analyses will be conducted together with partner TNO.