( ( Since ( carbohydrate ( has ( ( four calories ) ( per gram ) ) ) ) ) ( , ( that ( ( ( ( works out ) ( ( to 2,000 ) ( to ( ( ( as ( much ( as 3,200 ) ) ) calories ) ( per ( day ( from ( that ( one source ) ) ) ) ) ) ) ) ) alone ) . ) ) ) )
(ROOT (S (SBAR (IN Since) (S (NP (NN carbohydrate)) (VP (VBZ has) (NP (NP (CD four) (NNS calories)) (PP (IN per) (NP (NN gram))))))) (, ,) (NP (DT that)) (VP (VBZ works) (PRT (RP out)) (PP (PP (TO to) (NP (CD 2,000))) (PP (TO to) (NP (NP (QP (RB as) (JJ much) (IN as) (CD 3,200)) (NNS calories)) (PP (IN per) (NP (NP (NN day)) (PP (IN from) (NP (DT that) (CD one) (NN source)))))))) (ADVP (RB alone))) (. .)))
Since carbohydrate has four calories per gram, that works out to 2,000 to as much as 3,200 calories per day from that one source alone.
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NNS carbohydrates)))) (VP (VBZ provides) (NP (NP (CD four) (NNS calories)) (PP (IN of) (NP (NN energy))))) (. .)))