Possible Clues:

• Trendy food from the Andes
• One in five love a superfood
• One of five children initially offered a substitute for rice?
• Protein-rich seeds
• South American goosefoot with leaves used like spinach
• Grain plant's former boss in Philippines keeping head down
• Food staple referred to as 'the gold of the Incas'
• South American "supergrain" in health stores