The culture of extreme weight cutting is the most dangerous regulatory issue in mixed martial arts, which is already an inherently dangerous sport.

Dehydration is medically classified as mild, moderate, or severe depending on the percentage of body weight lost. Mild dehydration is said to be present with fluid losses of 5-7%. Moderate dehydration is 8% to 10-11%. Severe dehydration is 11-12% or more of body weight; it requires immediate medical care. Death occurs at a loss of between 15% and 25% of the body water.

Andy Foster, executive director of the California State Athletic Commission, has been gathering data since January, and 10% (or 28 out of 285) of MMA fights in California saw one or both fighters weighing over 15% above the contracted weight on fight day. By contrast, in boxing the rate was just 1.6% (or 9 out of 570). To give an example from MMA, this would be a bantamweight (136 non-title limit) weighing more than 155.2 on fight day, or two divisions up. Weight divisions are implemented for fighter health and safety, yet in this pursuit of “safety” a significant percentage of fighters are enduring a potentially fatal level of fluid loss. 

Foster does not want fighters cutting to the cusp of a potentially fatal degree of dehydration, one day before putting their bodies through the tremendous ordeal that is a fight.

During a CSAC meeting on Tuesday, a new rule was passed, that would cancel a fight if on fight day a competitor weighed more than 15% over the contracted fight weight. Further, trainers, promoters, matchmakers, and managers, will be responsible for making sure fighters comply with the new rule. It passed by a vote of 5-0.

There is the potential now that fighters will not fully rehydrate before a fight, but Foster explained that the aim is to get promoters to match fighters at closer to their natural weight. The alternative for promoters is seeing a bout canceled.

“The only way we can get there is out of fear of a cancellation,” said Foster to Marc Raimondi for ESPN. “I suspect the matchmakers will probably just move the fights up a little bit if they see weights increase just to prevent risks to their promotions.”

Foster would also like promoters to hold more catchweight fights. This is another sensible step, as fans want to watch good fights, not watch fights at any given weight division.

“This is a fixable issue,” said Foster. “Pretending like we’re bound to these weight classes like they’re set in stone and fighters can’t move up, frankly it’s not healthy.”