A measuring device includes a first body, a second body slidably combined with the first body, a first pressure sensing component, and a control unit. The first body is for supporting a cup receiving liquid. The first pressure sensing component is disposed between the first body and the second body for sensing weight of the cup and the liquid and generating a signal corresponding to the weight. The control unit is electrically connected to the first pressure sensing component. The control unit determines a volume variation of the liquid according to a weight variation of the cup and the liquid calculated based on a difference between signals transmitted from the first pressure sensing component at different time points.

A meal consumption monitoring and control system is disclosed. The system includes a flat profile scale serving as a coaster for a plate, a cup, or a glass enabled with Bluetooth or other type of wireless connectivity. The scale is connected to an accompanying mobile application installed on a mobile device. The mobile application is connected to the accompanying server-side cloud bases software application. The method for motivating children to consume meal in whole and without significant interruptions includes displaying a children content on the mobile device during the meal consumption, pausing the content when there is a significant delay registered in the meal consumption process, and resuming the content and/or providing certain awards to the child when the child resumes taking meal. The method for automatically controlling the consistency of the eater's nutrition includes collecting meal descriptions and weight data at every meal taking session, and storing the collected data on the cloud for further access by the eaters and/or their parents/guardians.