Weight cutting under 18: a guide for coaches and parents

This one is written for the adults, deliberately. A 14-year-old is not the person who should be weighing up this decision, and in practice he is not the person making it.

Scientific reviews normally end in careful language about further research being needed.

The 2022 systematic review of weight cycling in youth combat sport ends by saying rapid weight loss in this population needs to be stringently regulated and ideally banned.

That is not how these papers usually finish, and I would pause on it.

How common it is

Depending on the sport, age and level of competition, between 25% and 94% of young combat athletes engage in rapid weight loss. The magnitude runs from around 1% of body mass up to roughly 6%.

The starting ages are the part that stops people.

In a cohort of 822 judo athletes across Brazil, researchers found children beginning the practice as young as 4 years old. The same finding appeared in Israeli judo.

A published case study from the United States describes a 5-year-old cutting weight for a wrestling competition.

Four years old. Not competing at four. Cutting weight at four.

How early it starts, and who is advising

Two findings from a 2024 systematic review of weight loss practices covering 26 studies, 3,994 athletes and 14 combat sports.

The first is when it begins. Many athletes start cutting weight in adolescence, and go through it 2 or 3 times a year from then on. Not once, not as an exception.

As the annual rhythm of the sport, beginning before the body has finished growing.

The second is who tells them how. The review found the influence of qualified professionals on these practices to be very low. The advice comes from coaches, training partners and former athletes.

That describes a gap rather than criticising coaches. A coach passes on what worked for him, who got it from somebody who got it from somebody, and the chain has no point at which anybody checked whether it was safe for a 15-year-old.

Prevalence across those studies averaged around 89 percent, with individual studies ranging from two thirds to all of the athletes sampled.

Whatever a parent hopes is happening in the gym, the base rate says otherwise.

What it does to a growing body

Adolescents who repeatedly diet to stay in the lowest possible weight class can impair their own growth. That is the review's central concern, and it is specific to this population: an adult who cuts badly recovers, while a child who does it through puberty may not get the height back.

Documented alongside it: cardiac arrhythmias, electrolyte disturbance, heat illness, renal strain and effects on long-term bone health.

Two further findings sit slightly to the side and matter as much.

• Adolescent wrestlers who cycled their weight regularly showed lower resting metabolic rates than teammates who did not, with reported figures around 14%.
• In a German study of wrestlers competing in the lower weight categories, 52% reported a history of bingeing, and 11% met the profile for a subclinical eating disorder.

The second one is the reason I will not write a technical protocol for this age group. A child taught to control his body through restriction, at the age when eating habits are being set, is being taught something that outlasts the sport by decades.

The finding nobody connects

Wrestlers performed worse on concussion screening tests when dehydrated than they did at baseline when normally hydrated.

Sit with the implications of that in a combat sport.

What the rules already require

Some governing bodies took this seriously decades ago, and their frameworks are worth borrowing even where they do not formally apply to you.

The consensus position of the field is that the fix belongs to organisations rather than to education aimed at athletes.

Two things sit underneath that. Which ages each sport permits to compete at all is set out in old enough to compete, old enough to cut. What a working minimum weight programme looks like, in the one place that built one, is in the minimum weight rules nobody enforces.

American collegiate and high school wrestling operate a minimum weight programme. Male wrestlers may not compete below 5% body fat. Each athlete has a minimum competition weight calculated for him, and the rate at which he may descend toward it is capped per week.

Saunas, hot rooms, rubber suits, laxatives and diuretics are prohibited.

Under the high school rules the process of establishing that safe minimum weight formally involves four people: the wrestler, the parent or guardian, a health-care professional, and the coach.

Four signatures. That structure exists because the sport learned, expensively, that leaving the decision to a teenager and one adult with a competitive interest does not work.

What to do instead, concretely

Telling a family not to cut weight is easy and useless on its own. Here is what replaces it.

The problem that exists only in this age group

An adult returning to the same division next year is returning to the same body. A 15-year-old is not.

A young athlete can gain several kilograms and several centimetres between seasons through growth alone, none of it optional and all of it wanted. Hold the division constant across that and you have not maintained anything.

You have created a cut that grows every year while looking, on paper, like consistency.

This is how a family that never intended to cut weight ends up cutting a great deal of it. Nobody decided to. The division stayed where it was and the child grew.

The signal to watch is the trend rather than any single scale reading. A growing athlete whose weight is flat across 6 months is either ill, under-eating, or being managed toward a number, and all three deserve a conversation.

What I would tell a parent

Ask what the plan is, in writing, before the season. Not the target weight. The route to it, the rate, and who is supervising. If nobody can write it down, there is no plan.

If you want that as something to use rather than to agree with, six questions to ask your child's coach is the version you can take to a conversation, and the warning signs are what to look at before you have it.

Ask what division he would compete in with no cut at all. Then ask what is actually gained by going below it.

Often the honest answer is a slightly easier draw, purchased at a price nobody has priced.

Watch for the things that are not about weight. Secrecy around food. Refusing to eat with the family. Preoccupation with the scale between competitions. Mood changes in the days before a weigh-in. These are eating disorder signals and they are the outcome I worry about most, because it is the one that does not end when he stops competing.

Know that the coach may be wrong and still be a good coach. Most of them learned this from their own coach, in a decade when nobody was measuring the damage. What looks like harshness is usually inheritance, and it can be interrupted by one adult asking a question.

What I would say to the coach

You will hear that the boy wants it. He probably does. He is 14, he wants to win on Saturday, and he has no way of weighing that against a bone density measurement he will not see for 30 years.

That is precisely why the decision is not his.

The version I would defend: compete at natural weight through growth. Move up when he grows. Treat the weigh-in as something to arrive at, not something to survive.

If the number requires anything beyond ordinary sensible eating, the division is wrong and there is another one above it.

Where I stand on this

I plan weight cuts for a living. I am not against the practice as a matter of principle, and I would not have a career if I were.

Under 18 I have no position to defend. The evidence base was built on adults, the reviewers who looked at children asked for a ban, and there is nothing to be won at that age that is worth what it costs to take.

Let him grow. He will spend the rest of his career making weight. He gets one go at being 15.

When that career does start, the first question is which division he can hold between camps, well before any question of how to cut, and the answer is a percentage rather than an opinion.