もっと食べないと体力が付きませんよ。

(some) more; even more; longer; further

to eat; to live on (e.g. a salary); to live off; to subsist on

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

stamina; endurance; physical strength; resilience; resistance to disease; strength of an organization (e.g. profitability, productivity, economic clout, stability, growth potential)

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to be attached; to be connected with; to adhere; to stick; to cling; to remain imprinted; to scar; to stain; to dye; to bear (fruit, interest, etc.); to be acquired (of a habit, ability, etc.); to increase (of strength, etc.); to take root; to accompany; to attend; to follow; to study with; to side with; to belong to; to possess; to haunt; to be lit; to be lighted; to be settled; to be resolved; to be decided; to be given (of a name, price, etc.); to be sensed; to be perceived; to be lucky; to become (a state, condition, etc.)

indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!