Final answer:
The validity of subtypes of bulimia referring to Dietary/Bingeing and Purging/Restricting does not align with medically recognized categories. Bulimia nervosa is differentiated into purging and non-purging subtypes, whereas binge eating disorder involves bingeing without purging.
Step-by-step explanation:
The two subtypes of bulimia that appear to have greater validity than the purging/non-purging types according to the information provided are Dietary/Bingeing and Purging/Restricting. However, the question does not seem to directly correlate with the provided information, as it suggests subtypes that are not commonly recognized in the literature or diagnostic manuals like the DSM-5. The recognized subtypes of bulimia nervosa are the purging type, where individuals engage in self-induced vomiting or abuse of laxatives, diuretics, or enemas, and the non-purging type, where individuals use other inappropriate compensatory behaviors, such as fasting or excessive exercise, without purging.
It's essential to note that these subtypes differ from binge eating disorder, which is characterized by binge eating without subsequent purging behaviors. Binge eating disorder is associated with distress and other health complications but does not involve the purging that characterizes bulimia nervosa.