Normal Weight Adults

Obese people typically have chronic low-grade inflammation. Based on short-term studies, this inflammation could affect the absorption, utilization, storage, and mobilization of iron, and individuals with inflammation might develop iron deficiency (ID) and anemia when inadequacy of iron intake is presented. The double burden of malnutrition is nowadays emerging as a major public health concern in many countries, including Thailand. Understanding the association of chronic inflammation among people with overweight or obesity (OW/OB) with long-term iron absorption and loss is important for developing appropriate policies and programs to promote iron balance and, consequently, optimal iron status and health outcomes. Since previous reports among Thai women showed a high prevalence of OW/OB and anemia, this study will be conducted to determine the long-term iron absorption and loss among OW/OB free-living women using the iron isotope dilution method.

The goal of this clinical trial is to characterize the pharmacokinetics (absorption, distribution, metabolism, and excretion; ADME) and oral bioavailability of tartaric acid in humans after its administration through different food matrices (red wine, fresh grapes, and grape juice). The study aims to determine whether the pharmacokinetic behavior of tartaric acid is matrix-dependent and dose-dependent in healthy adult volunteers. The main questions it aims to answer are: Does the food matrix (wine, grapes, or grape juice) influence the oral bioavailability of tartaric acid? Are there differences in key pharmacokinetic parameters of tartaric acid, including maximum plasma concentration (Cmax), time to reach maximum concentration (Tmax), total exposure (AUC), half-life (t1/2), and urinary excretion, depending on the matrix of intake? Researchers will compare the pharmacokinetic profiles of tartaric acid after consumption in red wine, grapes, and grape juice to evaluate differences in absorption, systemic exposure, and elimination attributable to the source of intake. Participants will: Follow a polyphenol-restricted diet prior to the study, including avoidance of grapes, wine, and related products. Consume a single standardized dose of tartaric acid administered as red wine, fresh grapes, or grape juice after an overnight fast. Provide blood samples at multiple time points over a 24-hour period to determine plasma tartaric acid concentrations. Collect urine samples over 24 hours for assessment of tartaric acid excretion. Consume standardized low-polyphenol meals under controlled conditions during the study day.

The goal of this observational study is to learn about low-grade inflammation in healthy individuals and individuals with overweight or obesity. The main questions it aims to answer are: * Whether it is possible to predict low-grade inflammation * What are the medical, biological, and lifestyle variables related to low-grade inflammation? Participants will be asked to: 1. Attend a general medical visit to collect vital signs, anthropometric measurements, and collect blood samples. 2. Complete questionnaires and collect a stool sample at home.