Final answer:
The type of study that observes a large population to determine factors that may influence nutritional habits and disease trends is called an epidemiological study.
Step-by-step explanation:
The type of study that observes a large population to determine factors that may influence nutritional habits and disease trends is called an epidemiological study.
Unlike case-controlled studies, which are retrospective and rely on participants recalling past behaviors, epidemiological studies often have a broader scope and may be prospective, following a group over time to observe outcomes and trends in health.
Observational studies like cross-sectional, case-control, and cohort studies are crucial in identifying risk factors for disease and forming the basis for preventive healthcare.