Two new studies indicate that many people become obese more due to the fact that their bodies burn
calories too slowly than overeating.
(A) due to the fact that their bodies burn calories too slowly than overeating
(B) due to their bodies burning calories too slowly than to eating too much
(C) because their bodies bum calories too slowly than that they are overeaters
(D) because their bodies bum calories too slowly than because they eat too much
(E) because of their bodies burning calories too slowly than because of their eating too much
E looks parallel and structured.
I don't mean to sound like a douche, but way too many times do I notice people in this forum use words like "looks parallel" or "the gerund is correctly used" or "the past participle is bla bla", and yet the correct answer flies over their heads..
Don't focus too much on technicalities, that's exactly what the GMAT wants you to do, to focus too deeply into technical aspects and miss the bigger picture. ESPECIALLY so for short problems like this one (longer, more convoluted problems need more in depth technical analysis).
If we look at E: "it has more to do with their BODIES burning calories too slow than because of THEIR eating too much" ... What are we comparing? What does the "their" refer to, the eating of the bodies? That makes no sense. No technical analysis needed, it's just seeing a clear picture of the intended meaning of the author.
D tells us that it has more to do with "THEIR (the people) bodies burning calories too slowly than because THEY (the people) eat too much".. THAT'S the correct comparison.
Focus on understanding the intended meaning, and when you get the intended meaning, that's when you can focous on technicalities. Start from step 1 and move up, don't start on step 5.