Abstract: An acetone concentration estimate device acquires a measured acetone concentration measuring acetone excreted from a user, acquires an elapsed time which has elapsed since the user ate a meal, and estimates an acetone concentration, which is a ketone body concentration of when an amount of change in blood sugar level of the user per given unit of time is stable, based on the acquired current measured acetone concentration and on the acquired elapsed time, and outputs information corresponding to the estimated acetone concentration.

Abstract: A biological gas detection device acquires a reference output value that is an output value outputted from a semiconductor gas sensor in a reference air sample, the semiconductor gas sensor having sensitivity to an interfering gas and a target gas contained in a biological gas, acquires a target gas concentration that is a concentration of the target gas measured based on a first output value, the first output value being outputted from the semiconductor gas sensor during measurement of the biological gas, corrects the target gas concentration based on a second output value and the reference output value, the second output value being outputted from the semiconductor gas sensor in an air sample prior to measurement of the biological gas; and outputs information according to the corrected target gas concentration.

Abstract: A body composition change prediction device acquires a measured acetone concentration measuring acetone excreted from a user, acquires current body composition information and past body composition information of the user, computes a prediction value predicting the body composition information at a given future point in time based on information relating to the body composition of the user, and determines a fat burning style of the user based on the acetone concentration and the current body composition information. The body composition change prediction device weights the prediction value based on a weight, the weight being set according to the burning style and being a greater weight the higher the measured ketone body concentration, and outputs information according to the weighted prediction value.

Abstract: An acetone concentration estimate device acquires a measured acetone concentration measuring acetone excreted from a user, acquires an elapsed time which has elapsed since the user ate a meal, and estimates an acetone concentration, which is a ketone body concentration of when an amount of change in blood sugar level of the user per given unit of time is stable, based on the acquired current measured acetone concentration and on the acquired elapsed time, and outputs information corresponding to the estimated acetone concentration.

Abstract: A biological gas detection device acquires a reference output value that is an output value outputted from a semiconductor gas sensor in a reference air sample, the semiconductor gas sensor having sensitivity to an interfering gas and a target gas contained in a biological gas, acquires a target gas concentration that is a concentration of the target gas measured based on a first output value, the first output value being outputted from the semiconductor gas sensor during measurement of the biological gas, corrects the target gas concentration based on a second output value and the reference output value, the second output value being outputted from the semiconductor gas sensor in an air sample prior to measurement of the biological gas; and outputs information according to the corrected target gas concentration.