Rapid weight loss strategies (including fasting and dehydration) and weight cycling (losing and gaining weight repeatedly) are acknowledged problems in sports with weight categories, including judo. While extreme fasting, especially if combined with dehydration and intense physical activity, may harm health and development, particularly of children and teenagers engaging in judo competitions, there is substantial evidence for positive health effects of other forms of fasting. Here we aim to provide an updated overview on potential health risks associated with extreme dietary strategies in judo and put them in context with health-promoting fasting approaches. We conclude that the literature on long-term health consequences of fasting in judo are scarce. This applies specifically to the potential association with eating disorders. Many reports highlight short-term risks of rapid weight loss, however, vulnerability and protection factors remain poorly understood. Rigorous scientific studies are needed to disentangle the factors that render fasting in judo healthy or hazardous, considering long-term effects both for somatic and mental health. We argue that better understanding of weight management in judo may be used to prevent health risks for athletes and possibly also to propose novel weight management strategies to overweight individuals.