food for thought

:  material consisting essentially of protein, carbohydrate, and fat used in the body of an organism to sustain growth, repair, and vital processes and to furnish energy

:  such food together with supplementary substances (such as minerals, vitamins, and condiments)

:  inorganic substances absorbed by plants in gaseous form or in water solution

: past tense and past participle ofthink

:  something that is thought: such as

:  an individual act or product of thinking

:  a developed intention or plan