Answer:
The percentage of overweight kids in America had doubled between 1987 and 2007, so the U.S. Government issued guidelines for healthful eating and exercise.
Step-by-step explanation:
The US government in collaboration with the U.S. Department of Agriculture (USDA) and the Health and Human Services (HHS) issued certain guidelines for healthy consumption and eating habits of the people. The Dietary Guidelines for Americans (Dietary Guidelines) was first introduced in 1800 to help Americans tackle their health and dietary intake of food.
The given sentence contains two independent clauses. Therefore, to connect the two, we need a coordinating conjunction and a comma, with the comma coming before the coordinating conjunction. Thus, the resulting sentence becomes a compound sentence.
So, the correct and complete sentence will be
The percentage of overweight kids in America had doubled between 1987 and 2007, so the U.S. Government issued guidelines for healthful eating and exercise.