( ( ( One gram ) ( of fat ) ) ( ( ( ( has ( nine calories ) ) , ) ( while ( ( ( one gram ) ( of ( ( protein or ) carbohydrates ) ) ) ( has ( ( only four ) calories ) ) ) ) ) . ) )
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NN fat)))) (VP (VBZ has) (NP (CD nine) (NNS calories)) (, ,) (SBAR (IN while) (S (NP (NP (CD one) (NN gram)) (PP (IN of) (NP (NN protein) (CC or) (NNS carbohydrates)))) (VP (VBZ has) (NP (QP (RB only) (CD four)) (NNS calories)))))) (. .)))
One gram of fat has nine calories, while one gram of protein or carbohydrates has only four calories.
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NNS proteins)))) (VP (VBZ provides) (NP (NP (CD four) (NNS calories)) (PP (IN of) (NP (NN energy))))) (. .)))