How to Cut Weight for a Fight: Safe Week-by-Week Plan

Contents

To cut weight for a fight safely, lose most of the weight slowly as body fat during camp, about 0.5–1 kg per week, and leave only a small, planned water cut for fight week (Ricci et al., 2025). How big that final cut can be depends on how many hours you have between weigh-in and fight. Then you need a real rehydration and refuel plan for after the scale.

Whether you box, fight MMA, kickbox or do Muay Thai, a badly planned cut can cost you more on fight night than your opponent. Here is the week-by-week plan, with the numbers the research supports.

How much weight can you cut safely?

Start from where you walk around, not from the last week. The ISSN suggests staying about 12–15 % above your weight-class limit in the off-camp phase. It treats that as the upper limit of a suitable weight descent (Ricci et al., 2025).

The acute part, the water and gut content you drop just before the weigh-in, should scale with your recovery window. These are the ISSN’s suggested sweat-loss ranges. The authors say they are based on their practical experience with athletes, so treat them as upper guides, not targets (Ricci et al., 2025):

Time from weigh-in to fight	Suggested net loss via sweat	Typical examples
Under 4 h	0–3 % (glycogen not fully depleted)	BJJ, wrestling, most amateur events
4–12 h	2–4 % (glycogen not fully depleted)	Amateur Muay Thai, Olympic boxing
12–24 h	3–5 %	Weigh-in the day before
24–36 h	4–6 %	Professional MMA, pro Muay Thai, kickboxing, boxing

Bigger is not better. Larger cuts of ~5 % of body mass in under 24 hours impair repeat-effort performance (Barley et al., 2019). If your gap is bigger than your window allows, the honest fix is a higher weight class. Check your numbers in how much weight you can cut.

The weight cut timeline: 8+ weeks to weigh-in

Spread the work out so fight week only finishes the job. This timeline is built from the ISSN position stand. Adjust it with your coach.

When	Phase	What you do	Guardrail
Off-camp	Maintenance	Stay no more than ~12–15 % above your limit	ISSN off-camp range
8+ weeks out	Camp starts	Moderate calorie deficit, protein 1.6–2.2 g/kg, carbs at least 3–4 g/kg	Lose 0.5–1 kg per week
8–2 weeks out	Weight descent	Morning weigh-ins, adjust on the weekly trend	About 0.7 %/week protects lean mass
~2 weeks out	Buffer check	Work out how much must come off acutely, and compare it to your window (table above)	If it doesn’t fit, change class
Final 5–7 days	Fight week	Optional: low fibre, lower carbs, moderate sodium cut, water loading	Glycogen and fibre each ~1–2 %
72–24 h out	Final approach	Track how much is left each day	UFC fighters averaged 6.7 % over at 72 h, 4.4 % at 24 h
Final 24 h	Acute water cut	Small, supervised water loss only	~2–4 % of body mass in the last 24 h
After weigh-in	Recovery	Rehydrate with sodium, refuel with carbs	See the rehydration guide

Sources for the table: Ricci et al., 2025; lean-mass rate from Garthe et al., 2011.

Weeks 8 to 2: lose fat, keep your training

This is where the real weight comes off. Aim for 0.5–1 kg per week, and never eat below your resting metabolic rate (Ricci et al., 2025). In elite athletes, losing about 0.7 % of body weight per week increased lean mass, while about 1.0 % per week only maintained it (Garthe et al., 2011).

• Keep protein at 1.6–2.2 g/kg and carbohydrate at no less than 3–4 g/kg so you can still train hard (Ricci et al., 2025).
• Weigh yourself every morning under the same conditions and judge the weekly average, not single days.

Our guide to fight camp calories and macros shows how to set and adjust the numbers.

Fight week: water, glycogen and gut content

Fight week removes weight that isn’t fat: gut content, water stored with glycogen, and some body water. The ISSN describes these tools (Ricci et al., 2025):

• Low fibre: below 10 g per day for about 4 days can reduce body mass by about 1–2 %.
• Lower carbohydrate plus training: depleting glycogen, which binds water, can take off about 1–2 %.
• Sodium: if your normal intake is higher, bring it down toward about 2.3 g (2,300 mg) per day in fight week, and not lower, because you still lose sodium in sweat.
• Water loading: a few days of high fluid intake followed by restriction increases urine output. Read the water loading guide before you try it.

In the last 24 hours, supervised acute water loss of about 2–4 % of body mass is the ISSN’s suggested range. Hot methods like the sauna need close supervision and core-temperature monitoring (Ricci et al., 2025).

Reale and colleagues’ review sets out a decision tree for the same question: choose the combination of methods that reaches the target with the smallest performance cost (Reale et al., 2017).

After the weigh-in: rehydrate and refuel

The fight is won in the ring, not on the scale, so plan the refuel as carefully as the cut. The ISSN recommends oral rehydration solutions at 1–1.5 litres per hour right after the weigh-in, then fast carbs at up to 60 g per hour (Ricci et al., 2025). The full hour-by-hour plan is in how to rehydrate after the weigh-in.

Know your rules. ONE Championship requires a passed hydration test, urine specific gravity of 1.025 or lower, at a combined weigh-in 24–48 hours before the event (ONE Championship). A classic dehydration cut won’t work there.

What not to do: dangerous weight cut methods

Some methods are banned, some are dangerous, and some are both. Avoid:

• Diuretics and laxatives. The ISSN lists them as potentially harmful. Diuretics are on the World Anti-Doping Agency’s prohibited list (Ricci et al., 2025).
• Spitting, vomiting, rubber suits and last-minute sauna sessions to fix a missed weight. The ACSM lists these as harmful practices (Burke et al., 2021).
• Huge, late cuts. Deaths linked to extreme weight making have been reported in MMA, Muay Thai, judo, taekwondo and college wrestling (Burke et al., 2021).

A published case study of an elite MMA athlete shows what an extreme cut does. He lost 18.1 % of his body mass (80.2 to 65.7 kg) over 8 weeks. The final 24 hours of dehydration (9.3 % of body mass) caused abnormally high blood sodium and acute kidney injury (Kasper et al., 2019). A systematic review found the largest regains after weigh-in in MMA, about 7.4 kg. By regaining weight, athletes may compete up to three weight categories above the one they weighed in at (Matthews et al., 2019). That is exactly the arms race to stay out of.

Can you cut 10 pounds in 2 weeks?

Only partly as real weight loss. At the 0.5–1 kg per week the ISSN recommends, two weeks gives about 1–2 kg, or roughly 2.2–4.4 lb (Ricci et al., 2025). The remaining 5.6–7.8 lb would have to come off as water, glycogen and gut content in fight week.

How hard that is depends on your size. For a 70 kg (154 lb) fighter, 10 lb (4.5 kg) is about 6.5 % of body weight. For a 90 kg (198 lb) fighter it is about 5 %. Leave a cut like that to the last day, and you are in the range of ~5 % in under 24 hours that impairs repeat-effort performance (Barley et al., 2019). If you are two weeks out and 10 lb heavy, talk to your coach about a catchweight or a different division.

The five classic weight cut mistakes

1. Starting too late: a panic cut in the last week instead of steady fat loss.
2. Trusting one weigh-in: daily swings are water, salt and food. The weekly trend is what counts.
3. Crash dieting in camp: too big a deficit wrecks training, and training wins fights.
4. Copying someone else’s cut: your body, your division and your weigh-in window are your own.
5. Forgetting the refuel: a good cut with a bad recovery is still a bad cut.

New to all of this? Start with weight cutting for beginners.

With MyFightPrep you get morning weigh-ins, a weight trend toward your fight date, a food log with an AI meal scanner and water loading planning in one place — free.

Important

This guide is general information, not medical advice. Rapid weight loss and dehydration can be dangerous and have caused deaths. If you are under 18, and wrestlers especially, follow your federation’s weight-management rules and do not dehydrate to make weight. Work with your coach and a doctor or sports dietitian, and cut less than you think you can. Stop immediately and seek medical help if you experience dizziness, confusion, fainting, chest pain, a racing heart, severe cramps or very little or dark urine.

Frequently asked questions

How do you cut weight for a fight?

In two phases. First you lose body fat gradually over the camp, about 0.5 to 1 kg per week. Then, in fight week, you temporarily reduce water, glycogen and gut content to make the scale, and rehydrate and refuel after the weigh-in.

How do you cut weight fast for a fight?

The fast part of a cut is the acute phase in fight week: lower fibre, lower carbohydrate, moderate sodium reduction and, under supervision, a small water cut. The ISSN puts supervised acute water loss at about 2 to 4 % of body mass within 24 hours; larger, faster cuts carry more risk to performance and health.

What do fighters eat to cut weight?

In camp, normal whole foods in a moderate calorie deficit with plenty of protein. In the last days before the weigh-in, many switch to low-fibre, lower-carbohydrate meals with moderate salt to reduce gut content and water held with glycogen, then eat carb-rich food after the weigh-in.

Can I cut 10 pounds in 2 weeks?

Only partly as real weight loss. At the recommended 0.5 to 1 kg per week, two weeks gives about 2.2 to 4.4 lb, so the rest would have to be water and gut content in fight week. For a 154 lb (70 kg) fighter, 10 lb is about 6.5 % of body weight, which is a large acute cut.

Sources

This guide is based on the works below. Numbers in the text refer to them.

1. Ricci AA, Evans C, Stull C, Peacock CA, French DN, Stout JR, et al. (2025). International Society of Sports Nutrition Position Stand: Nutrition and Weight Cut Strategies for Mixed Martial Arts and Other Combat Sports
2. Burke LM, Slater GJ, Matthews JJ, Langan-Evans C, Horswill CA (2021). ACSM Expert Consensus Statement on Weight Loss in Weight-Category Sports
3. Reale R, Slater G, Burke LM (2017). Acute-Weight-Loss Strategies for Combat Sports and Applications to Olympic Success
4. Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J (2011). Effect of Two Different Weight-Loss Rates on Body Composition and Strength and Power-Related Performance in Elite Athletes
5. Barley OR, Chapman DW, Abbiss CR (2019). The Current State of Weight-Cutting in Combat Sports
6. Matthews JJ, Stanhope EN, Godwin MS, Holmes MEJ, Artioli GG (2019). The Magnitude of Rapid Weight Loss and Rapid Weight Gain in Combat Sport Athletes Preparing for Competition: A Systematic Review
7. Kasper AM, Crighton B, Langan-Evans C, Riley P, Sharma A, Close GL, Morton JP (2019). Case Study: Extreme Weight Making Causes Relative Energy Deficiency, Dehydration, and Acute Kidney Injury in a Male Mixed Martial Arts Athlete
8. ONE Championship (2026). Martial Arts: weigh-in and hydration testing rules