A Number of Popular Diets Have Been Tested by Research

Multiple Choice

A number of popular diets have been tested by research studies; however,most of the people in the studies were unable to stick to a particular diet for a year,primarily because _____.​

A) ​it was too hard to follow
B) weekly weight-loss was insufficient
C) protein intake was too low
D) fat intake was too low
E) ​carbohydrate intake was too low