Final answer:
The disagreement between researchers regarding food addiction as a mental disorder is centered around its classification and inclusion in diagnostic systems.
Step-by-step explanation:
The disagreement between researchers regarding whether food addiction should be considered a mental disorder revolves around the issue of classification and inclusion in diagnostic systems. Some researchers argue that food addiction should be recognized as a mental disorder in future versions of diagnostic systems, while others argue that it is not a real addiction and should not be included. This disagreement is centered around the conceptualization and definition of food addiction as a mental disorder.