1. A method of sensing wearer activity using an electronic device worn by a wearer, the method comprising: providing storage for event-specific parameters, initialized for a food intake event; providing storage for an event state value, wherein the event state value is one of an out-of-event state or an in-event state, with the event state value initialized to the out-of-event state; determining, using a processor in the electronic device or communicatively coupled to the electronic device, a set of sensor readings from a set of sensors in the electronic device, wherein at least one sensor reading of the set of sensor readings measures a movement of a body part of the wearer and is usable to modify the event state value for use in initiating recording gestures and thus alter an event state of the electronic device; determining, from the set of sensor readings and using the processor, a first potential gesture of the wearer including a gesture type of the first potential gesture, wherein some of the gesture types are members of a first set of gesture types, the first set of gesture types including a sip gesture type; determining, using the processor, if the first potential gesture has a sip gesture type by distinguishing a sip gesture from other gestures, thereby determining a determined gesture type of the first potential gesture; determining, from the set of sensor readings and using the processor, a confidence level related to the first potential gesture, wherein the confidence level relates to a level of confidence that the gesture type of the first potential gesture was correctly determined and would be indicative of a change of the event state; if the confidence level is above or at a threshold and the gesture type is a member of the first set of gesture types: (a) modifying, using the processor, the event state value in the storage for the event state value from the out-of-event state to the in-event state; (b) recording the first potential gesture as a first gesture of the food intake event; and (c) recording the determined gesture type; changing, using the processor, the electronic device to a higher performance state in response to the event state value being modified from the out-of-event state to the in-event state, wherein the higher performance state comprises one or more of additional power supplied to sensors of the set of sensors, additional power being drawn by the sensors of the set of sensors, a reduced latency of a communications channel, an increased sensor sampling rate of the sensors of the set of sensors, additional computations performed by the processor, and/or activation of a data recorder; determining, from a set of additional sensor readings and using the processor, additional gestures of the wearer, each having a respective gesture type; and if the event state value stored in the storage for the event state value is the in-event state: (a) recording the first gesture and the additional gestures as a gesture sequence of the food intake event; and (b) deriving the event-specific parameters about the food intake event from at least some gestures of the gesture sequence.