The HotFacets study is a randomized, controlled, cross-over meal study that investigates the acute effects of alcohol consumption on short-chain fatty acids dynamics, energy metabolism, and biomarkers. Despite the negative health consequences of chronic alcohol abuse, observational and cohort studies associate moderate alcohol consumption with a 20-30 % lower risk of cardiovascular diseases (CVD) and Type 2 Diabetes Mellitus (T2DM), compared to abstainers. Based on the J-shaped relationship between alcohol intake and the risk of cardiometabolic diseases, ½-2 standard drinks/day can be considered as moderate alcohol consumption. The interpretation of the J-shaped relationship has been criticized mainly due to potential confounding from the selected reference group and uncontrolled lifestyle factors. Longer, well-designed randomized controlled trials are lacking to infer causality and to clarify the mechanism of action for the acute and chronic effects of moderate alcohol consumption on cardiometabolic health and energy homeostasis. However, some aspects of alcohol metabolism and biomarker validation could inform such a study. HotFacets is set to generate insight into the effects of acute alcohol intake on SCFA dynamics in blood, urine, and faeces; into the dose-response relationship with REE, thermogenesis, substrate oxidation, and alcohol biomarkers; and to explore potential low levels of alcohol produced in the gut.