yo-yo dieting

Etymology
Akin to a yo-yo, which alternates between upward and downward movement.

Noun

 * 1) A series of failed diets that cause a person to lose and gain weight alternately.

Translations

 * Chinese:
 * Mandarin: 溜溜球效應
 * Dutch:
 * Finnish: jojolaihdutus, jojolaihduttaminen