( ( A ( simple ( way ( to ( ( understand ( the principle ) ) ( behind ( ( a comparison ) ( of ( starches ( , ( ( fats and ) protein ) ) ) ) ) ) ) ) ) ) ) ( ( is ( to ( realize ( that ( ( all carbohydrates ) ( ( ( have ( ( 4 calories ) ( per gram ) ) ) , ) ( whether ( ( sugar or ) ( a starch ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (JJ simple) (NN way) (S (VP (TO to) (VP (VB understand) (NP (DT the) (NN principle)) (PP (IN behind) (NP (NP (DT a) (NN comparison)) (PP (IN of) (NP (NNS starches) (, ,) (NNS fats) (CC and) (NN protein))))))))) (VP (VBZ is) (S (VP (TO to) (VP (VB realize) (SBAR (IN that) (S (NP (DT all) (NNS carbohydrates)) (VP (VBP have) (NP (NP (CD 4) (NNS calories)) (PP (IN per) (NP (NN gram)))) (, ,) (PP (IN whether) (NP (NP (NN sugar)) (CC or) (NP (DT a) (NN starch))))))))))) (. .)))
A simple way to understand the principle behind a comparison of starches, fats and protein is to realize that all carbohydrates have 4 calories per gram, whether sugar or a starch.
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NN sugar) (CC or) (NN starch)))) (VP (VBZ provides) (NP (NP (CD 4) (NNS calories)) (PP (IN of) (NP (NN energy))))) (. .)))