Question

which method of gathering data will be most effective in learning how diet and fitness choices affect long-term health?

an experiment
an observational study
a sample survey
a census

Explanation:

Analyze the research goal

The objective is to learn how diet and fitness choices affect long-term health. This requires tracking individuals over a long period to see how their natural lifestyle choices correlate with health outcomes.

Evaluate the feasibility of an experiment

Using the Experimental Study knowledge point
An experiment requires assigning treatments to subjects. Forcing people to follow strict diets or exercise regimens for decades is unethical and practically impossible.

Evaluate an observational study

Using the Observational Study knowledge point
An observational study measures variables of interest without influencing the subjects. Researchers can track people's self-chosen diets and fitness habits over many years to observe long-term health outcomes naturally and ethically.

Compare other options

Using the Statistical Study Types knowledge point
A sample survey or census only captures a snapshot of self-reported data at a specific point in time, which is not effective for establishing long-term health developments.

Answer:

• an experiment
• an observational study (Correct answer)
• a sample survey
• a census