Why Weight Cutting Is Dangerous

Greenletes / Sports Nutrition / Why Weight Cutting Is Dangerous

Weight cutting is not doing what you think. The risky obsession with weight in sport definitely does more harm than good and can be dangerous.

By Juan Castillo (Reviewed by Natalie Rizzo, MS, RD)

Many athletes think that leaner equals fitter and quicker.  But is dropping weight quickly helping or hindering your performance? Spoiler alert– weight cutting isn’t doing what you think it is, and many people may be getting more than they bargained for when they drop weight quickly.

Here’s a rundown on the dangerous tactics of weight cutting, why people do it, and the potential health consequences.

person standing on a scale

What is Weight Cutting?

Weight cutting, or simply “cutting,” is the process of dropping a large amount of  body mass– including body fat and body water–in a very short  period of time. Whereas losing  0.5 to 2 pounds per week is considered normal weight loss, weight-cutting usually far exceeds that pace with athletes losing double digit pounds in a few days or a week. 

Whether for aesthetics or athletic competition, weight cutting usually includes some scary practices, like  severely cutting calories, fasting, forced dehydration, towel wrapping and/or sweat suits, and even medically abusive practices, like laxatives, diet pills, diuretics, enemas, and sporting bulimia (vomiting). 

Why do people do it?

Athletes weight cut for a variety of reasons, and many of them are dependent on the sport. 

Endurance Sports

In endurance sports like basketball or running, many believe being leaner and lighter will result in more speed and better overall performance. If a basketball player is already doing all they can in training to jump higher, they may begin to wonder if being lighter will help them get off the ground. Likewise, a sprinter may think they can shave a few milliseconds off their fastest time if they were only leaner.

Combat Sports

People in combat sports, like boxing, wrestling, and mixed martial arts (MMA), use weight cutting to qualify for their weight class. It is so ingrained in the culture that it is considered a standard part of preparing for a fight. 

In fact, for some fighters weight cutting is a strategy aimed to competitively qualify for a lower weight class and get mismatched with a naturally smaller opponent. 

woman boxer hitting a punching bag


Like combat sports, weight-cutting is considered standard practice in bodybuilding. They routinely bulk to pack on lots of muscle and then “cut” to reveal the muscle underneath the fat. The degree of weight-cutting is often more severe in bodybuilding, with some bodybuilders looking almost unrecognizable in their off-season (see the 2018 Mr. Olympia winner, Shawn Roden).

A note on weight bias

It is important to note that there is an ingrained weight bias in all sports and the public, and it leads people to embrace weight cutting, despite negative health consequences. Lower weight and visible muscles are associated with athleticism and health. This drives people to partake in weight cutting practices in pursuit of the “athletic” look.

Body fat also carries moral implications, implying a lack of self-control and dedication. This applies even to people who compete successfully at a high level. For instance, Andy Ruiz, the first Mexican heavyweight boxing champion of the world, was inundated with unsolicited diet advice after winning his titles in 2019, for no other reason than “not looking the part” of a top level athlete.

Unintentional consequences of weight cutting

Although the goal of weight cutting is to drop pounds quickly, there are other negative side effects.

Hormonal Imbalances

Because body fat is tied to hormone production, weight cutting has been found to influence testosterone, growth hormone, cortisol, and insulin levels. This can affect bone mineral density, reproductive health, and blood sugar regulation. 

Without enough body fat, females can experience a disruption to their reproductive cycle, with estrogen levels so low their menstruation becomes irregular or stops all together. Males can experience low testosterone levels associated with low body fat.

Eating Disorders

The practice of weight cutting can lead to distorted views of health and body image. Overly restrictive diet rules and over-exercising can develop into an eating disorder.  

Indeed, eating disorders are more prevalent in people that partake in athletic endeavors, whether competitive or not, and the prevalence of eating disorders is well documented in sports with significant emphasis on body image, like gymnastics and bodybuilding.

Increased Risk of Injury

The combination of low bone mineral density from low sex hormones and malnourishment can cause an athletes to be more vulnerable to injury. This could translate into a torn ACL, a damaged elbow, and even greater head trauma in the case of combat sports.

Cardiovascular Risks and Stroke

Acute dehydration can lead to a reduction in blood plasma and total blood volume. This can impair cardiovascular function, muscle blood flow, and the ability to regulate body temperature. The increased thickness of dehydrated blood is also associated with an increase in heart disease risk and stroke.

Poor Performance

One of the main components of calorie restriction is carb restriction, which leads to reduced glycogen stores. Since glycogen is needed  to perform at high intensities, this can negatively impact performance. Dehydration can also exacerbate overall fatigue and impair performance.

man running up stadium stairs


There have been several deaths associated with weight cutting. The wide use of sweatsuits, even in saunas, predisposes individuals to heat illness and heat stroke, which can be fatal.

How to lose weight in a healthy way 

Weight cutting is ingrained in sport and fitness and discouraging its practice is difficult, especially given the obsession with weight in the US. But before turning to drastic weight cutting,  consider these suggestions for reducing weight in a healthy way. : 

1. Set realistic goals for weight loss 

Losing weight too quickly is cause for concern. The below is a realistic amount of weight to lose in a given period of time:

  • <5% of body weight per month
  •  <7.5% of body weight in three months
  •  <10% of body weight in six months
  •   <20% of body weight in a year

2. Lose weight over time

Weight loss should happen gradually over time.  In addition to the aforementioned percentage rates, consider that losing half a pound to two pounds per week is considered the recommended rate of weight loss.

3. Consider your reason “why”

Understand that weight cutting does not promote health. It is simply a means to an end, whether that be competition or increased muscle visibility.

4. Avoid restrictive food rules

Highly restrictive food rules can increase the risk of developing disordered eating patterns. Instead of following crash diets, choose whole nutritious foods over processed foods when possible. And remember that eating itself is not a guilty pleasure, but one of life’s central joys – and literally the thing you do to stay alive.

5. Exercise a healthy amount 

Current aerobic guidelines recommend 150 minutes of moderate intensity activity or 75 minutes of vigorous activity. This usually breaks down to 30 minutes of aerobic activity per day, five days a week, though one hour instead of 30 minutes is not uncommon or unreasonable.

However, engaging in continuous aerobic activity, like running or cycling, for much longer than that (think two to four hours), with the primary intent of losing more weight, is considered excessive.

6. Stay properly hydrated  

Some combat athletes report using dehydration tactics to lose up to 9% of body mass in the 24 hours leading up to the weigh-in for a fight. This is not only excessive, it’s dangerous.

Hydration status itself can be identified through urine color and quantity. Greater degrees of dehydration are evident by smaller quantities of urine and more deeply orange/yellow urine.

Bottom line

The bottom line? Weight-cutting is not recommended. Its biggest problem is the break-neck speed and drastic methods required to lose a given amount of body mass in an unreasonable amount of time. Athletes that are looking for a competitive advantage through weight cutting need to ask themselves if it’s worth impairing performance or risking death. 

Juan Castillo is a masters candidate at Teachers College, Columbia University, studying nutrition and exercise physiology. He’s a certified personal trainer, and enjoys art, boxing, and submission grappling in his spare time.


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I’m Natalie Rizzo, an NYC-based Registered Dietitian.

My mission is to help everyday athletes fuel their fitness with plants.

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