The pattern you described, where someone alternates between periods of severe calorie restriction (starving oneself) and then consumes large quantities of food in a short period (binge eating) on another day, is often referred to as "binge-restrict" or "restrict-binge" cycle. This cycle is a common characteristic of an eating disorder called "binge eating disorder" (BED) or "bulimia nervosa."
Binge eating disorder (BED) is characterized by recurrent episodes of binge eating, during which an individual consumes an unusually large amount of food in a discrete period while experiencing a lack of control over their eating. Unlike bulimia nervosa, people with BED do not engage in regular compensatory behaviors, such as purging or excessive exercise, to counteract the binge episodes.
On the other hand, bulimia nervosa involves recurrent episodes of binge eating followed by compensatory behaviors like self-induced vomiting, misuse of laxatives or diuretics, fasting, or excessive exercise.
It's important to note that both binge eating disorder and bulimia nervosa are serious eating disorders that require professional intervention and support. If you or someone you know is experiencing such patterns of disordered eating, it's crucial to seek help from a qualified mental health professional or healthcare provider who specializes in eating disorders. Early intervention and treatment can lead to better outcomes and support the path to recovery.