Tracking diet and nutrition using wearable biological internet-of-things

A system for tracking diet and nutrition, comprising:

• an oral module configured to be affixed within a mouth of a user and including a set of salivary sensors responsive to a level of at least one nutrient;
• and
• a body module configured to be affixed adjacent to a body part of the user and including a set of eating event sensors responsive to an eating event,
• wherein the oral module further includes a probe antenna and a read-out circuit connected to the probe antenna, and the read-out circuit is configured to probe the set of salivary sensors through the probe antenna, and generate an output signal corresponding to the level of the at least one nutrient, and
• wherein the read-out circuit includes a phase-locked loop and a transconductance block, which are configured to generate a probe signal applied to the set of salivary sensors through the probe antenna, and the read-out circuit includes an amplitude detector to detect a response signal from the set of salivary sensors through the probe antenna.