A wearable apparatus comprising: an impedance sensor configured to measure an impedance signal in a body of a user; and a controller configured to: monitor changes in the impedance signal, determine, by using the measured impedance signal, a number of meals consumed during a certain time period and a glycemic index, GI, corresponding to each meal, provide eating habit information of the user based on the determined number of meals and the determined GI for each meal, determine a level of risk of eating habits of the user based on the eating habit information of the user, and control an output unit (210, 175) to output a warning notification when the level of risk of the eating habits of the user is greater than a predetermined level; wherein the impedance sensor comprises: a signal source configured to generate an alternating current, AC, power supply having at least two frequency ranges; a probe configured to receive the AC power supply and to transmit an AC signal to the body of the user in at least two directions using at least two tetrapolar circuits included in the probe, including a first direction based on muscle fibres and a second direction traversing the muscle fibres; and a signal sensor configured to receive the AC signal transmitted by the probe through the body of the user, and to convert the received AC signal into the impedance signal. an impedance sensor configured to measure an impedance signal in a body of a user; and a controller configured to: monitor changes in the impedance signal, determine, by using the measured impedance signal, a number of meals consumed during a certain time period and a glycemic index, GI, corresponding to each meal, provide eating habit information of the user based on the determined number of meals and the determined GI for each meal, determine a level of risk of eating habits of the user based on the eating habit information of the user, and control an output unit (210, 175) to output a warning notification when the level of risk of the eating habits of the user is greater than a predetermined level; monitor changes in the impedance signal, determine, by using the measured impedance signal, a number of meals consumed during a certain time period and a glycemic index, GI, corresponding to each meal, provide eating habit information of the user based on the determined number of meals and the determined GI for each meal, determine a level of risk of eating habits of the user based on the eating habit information of the user, and control an output unit (210, 175) to output a warning notification when the level of risk of the eating habits of the user is greater than a predetermined level; wherein the impedance sensor comprises: a signal source configured to generate an alternating current, AC, power supply having at least two frequency ranges; a probe configured to receive the AC power supply and to transmit an AC signal to the body of the user in at least two directions using at least two tetrapolar circuits included in the probe, including a first direction based on muscle fibres and a second direction traversing the muscle fibres; and a signal sensor configured to receive the AC signal transmitted by the probe through the body of the user, and to convert the received AC signal into the impedance signal. a signal source configured to generate an alternating current, AC, power supply having at least two frequency ranges; a probe configured to receive the AC power supply and to transmit an AC signal to the body of the user in at least two directions using at least two tetrapolar circuits included in the probe, including a first direction based on muscle fibres and a second direction traversing the muscle fibres; and a signal sensor configured to receive the AC signal transmitted by the probe through the body of the user, and to convert the received AC signal into the impedance signal.