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What can I eat during fight week?

What foods should I eat before I weigh in? 

What are the best foods to choose on fight week? 

How much weight can I lose on the week before a weigh in?

The answers to these questions will be revealed in the article below.


During part 1 we explained on how to set up a diet for a fight camp to help you improve body composition by, losing body fat, minimising micronutrient deficiencies, and maintaining performance whilst dieting. 

During the final week, attention shifts from being in a negative energy balance to lose body fat, to an acute strategy to lose weight. We can lose weight via 5 ways during the final week but only if we have maximized the diet during the fight camp by being on a high fibre carbohydrate diet. The 5 ways are as follows:

  1. Lower fibre intake
  2. Lower carbohydrate intake
  3. Lower sodium intake
  4. Reduce food weight with high energy foods
  5. Reduce water intake or do some voluntary dehydration with passive sweating. 

This article will explain how to do this in more detail, so that you can tweak your diet to lose the remaining pounds before a weigh in. 

In part 1, we explained that we like our athletes to be below 15-12% from their fighting weight when starting camp. This is so that we can aim to lose approx 1% of body mass per week up until the final week. During the final week we advise our athletes to be around 6-8% from their fighting weight 7 days out. The 5 strategies mentioned above can ensure that we quickly lose this remaining weight in the 7-day period. 

Most combat sport athletes who struggle during the final week either, start off fight week higher than 8% away from their fighting weight. Or stay too close to their fighting weight all week meaning that they are likely to feel fatigued and tired as well as likely being in a longer state of dehydration and hunger.

Remember, you only need to be on weight for the actual weigh-in, and not days before. This is one of the reasons why we feel that check weights need to be changed with the current science, as we know that athletes can lose up to 6-8% safely during the final week.

Lower fibre intake

Fibre intake is essential for aiding satiety (Howarth et al. 2001), improving gut health and reducing bowel diseases (Modan et al. 1975) whilst minimising constipation. The current guidelines are to consume 20-30g of fibre per day. We advise our athletes to achieve the higher end of this target during the fight camp diet. This is because research shows that if you reduce fibre intake from 27g per day to 10g or less for 5 days that you can lose up to 1% of body mass without reducing calories or carbohydrate intake, see figure 1 below (Foo et al. 2022). This occurs as fibre draws water into the intestines to help nutrient absorption whilst some food matter stays in the intestines to feed the microbiota. Reducing fibre intake will reduce the amount of water in the intestine as well as food matter. 

Examples of reducing fibre intake are as follows.

  • Swap brown and seeded bread for white bread
  • Swap brown rice for white basmati rice
  • Swap 100g of broccoli for 100g asparagus

A caveat to reducing fibre intake is that you will likely feel hungrier due to the high satiating effect of fibre and have less bowel movements. Participants in the study by Foo et al. (2022) reported increased feelings of hunger when consuming the low fibre diet. However, due to this being short term we do feel that this is a good strategy to be utilized for now. 

Figure 1. Graph showing the mean difference of 0.6kg between the low fibre diet group and habitual diet group (Foo et al. 2022).

Lower carbohydrate intake 

Carbohydrates contain 2.7g of water to 1g of carbohydrates. So, by reducing 100g of carbohydrates out of your diet, you would reduce your body mass by 370g. This is why many people lose a lot of weight in a short space of time when following a low carbohydrate ketogenic diet. For example, Sawyer et al. (2013) gave participants a carbohydrate restricted diet (Less than 50g) for 7 days compared to a normal carbohydrate intake (240-280g). The study found that participants in the carbohydrate restricted group reduced weight on average by 1kg and had no effects on strength outcomes such as hand grip strength, 1 RM bench press and squat. Albeit, the authors did not assess any high intensity repeated exercise performance teats. 

We don’t advocate a ketogenic diet during fight week for more than 5 days as we feel that it could reduce high intensity performance. Havemann et al. (2006), investigated the effects of a 6-day low carbohydrate intake (68% of energy from fat) followed by 2 days of carbohydrate loading (8-10g/kg) on a 100km cycling time trial (see table 1). The authors reported that the low carbohydrate intake group had significantly lower power output and higher sprint times compared to the high carbohydrate intake group (68% of energy from carbohydrates). Although, we don’t support a ketogenic diet, we do recommend lowering carbohydrate intake in a stepwise manner throughout the week for when training load reduces. 

Table 1. High fat and high carbohydrate diet group data from Havemann et al. (2006)

In part 1, we recommended consuming approx. 3g/kg of carbohydrates per training day. So, for a 70kg boxer that would be the equivalent of 210g of carbohydrates per day. During fight week we would recommend reducing carbohydrates to 1.5g/kg 4-6 days out, 1g/kg 2-3 days out and less than 0.5g/kg 1 day out before a weigh in. This would be the equivalent of losing 175g of carbohydrates and 472g of body mass throughout fight week. 

Lower sodium (salt) intake 

Sodium is the main electrolyte that is responsible to maintain the human body fluid balance as well as be important for contracting and relaxing muscles and conducting nerve impulses. As sodium accumulates, the body holds onto water to dilute the sodium which increases the amount of fluid around the cells and the volume of blood in the bloodstream (Meyer, Szygula and Wilk 2016).

He et al. (2001) investigated a high salt diet (350 mmol/d) compared to a low salt diet (10-20 mmol/d) in 104 patients. They reported that the low salt diet group lost a mean body mass of 1.82kg compared to the high salt diet (see table 2). A limitation of this study was that fluid intake was not controlled. So, we don’t know if the high salt diet group just drank more rather than retaining more water. Visser et al. (2009) investigated the effects of a high sodium diet (200 mmol/d) compared to a low sodium diet (50 mmol/d) for 7 days. They reported that the high sodium diet increased extracellular fluid volume and the participants who were on the high salt diet weighed heavier. However, this was dependent on BMI. Those with a lower BMI reported a less rise of extracellular fluid volume and body mass (Many boxers have a lower BMI compared to the general population).

Table 2. Blood pressure and laboratory date from He et al. (2001)

Heer et al. (2000) measured the effects of a high sodium chloride intake (50, 200, 400, 550 NaCL/day) on total body fluid retention in 32 healthy male participants. They reported that increasing sodium chloride intake had no effects on total body water and body mass. The authors from this study controlled energy intake and fluid intake compared to the previous studies. So, the question remains does a high sodium intake increase water retention and body mass or, is it because that those on a high sodium intake drink more due to thirst. 

Despite the differences in findings on sodium intake on water retention and body mass it still seems best practice to reduce sodium intake to be below 0.5g per day for 3-5 days before a weigh-in. It is assumed that lowering sodium intake could aid the loss of approximately 1% body mass from less fluid retention. A general rule of thumb when lowering sodium intake is to avoid adding salt to meals and reducing the use of ready made sauces and seasonings. Do not worry you can still use natural herb and seasonings such as garlic, paprika, dill and parsley to flavour your food.

Reduce food weight 

Another strategy to utilize during fight week is to consume food which is lower in volume and weight whilst still being high in calories. This means eating foods which are higher in fat. The reason why we do this is that we don’t want boxers to be in a large state of low energy availability heading into a fight. Past research shows that athletes who consume below 30kcal/kg of FFM per day are at risk of poor bone health, increased risk of illness (Mountjoy et al. 2018) and possible decreased neuromuscular performance and lowered testosterone (Jurov et al. 2021 and 2022; Tornberg et al. 2017). 

So, increasing energy intake from higher energy foods that weigh less will ensure that boxers can still lose body mass from ingesting lower weight of food whilst being on a higher energy availability. Examples of low food weight whilst being high in energy and fat are as follows.

  • Olive oil 
  • Coconut
  • Nut butters
  • Double cream
  • Whole greek yogurt
  • Dark chocolate
  • Unsalted butter

A in-house case study by us showed that you can lose approximately 0.5kg from lowering food weight whilst still consuming a similar amount of energy (see figure 2 below). A limitation of this strategy is that it can lead to constipation and reduced bowel movements. However, we feel that it is beneficial when used in the short term.

Figure 2. Example of reducing food weight whilst keeping calories as high as possible.

Reduce water intake or voluntarily dehydrate with passive sweating

The human body is made up of 70% water and has large storage compartments such as the muscles and organs. Water is essential for life. So, although we can lose a lot of weight by losing water, typically through sweating, we certainly don’t recommend doing so by large amounts. 1 litre of sweat loss equates to 1kg loss of body mass. We recommend that professional boxers with a day before weigh in, aim to lose no more than 3-4% of body mass by losing water. Those with the same day weigh in, we don’t advocate dehydrating other than reducing drinking on the day up until the weigh-in if needed.

Although, the human body can do more in some circumstances, this can come with performance impairments and increased risk of life-threatening injuries. Evidence shows that 2% dehydration reduces performance acutely (Funnel et al. 2018), whereas up to 4.2% dehydration does not seem to deteriorate performance when you are able to rehydrate (McCartney, Desbrow and Irwin 2017). However, we still don’t know if organs can rehydrate effectively within a 1 day period especially in the brain.

Ceylan, Aydos and Simenko (2022) investigated the effects of 5% rapid weight loss on judo performance following 15h of rehydration after a weigh in. The study found that participants in the rapid weight loss group were still dehydrated after 15h when able to rehydrate. A limitation of this was that the judo boxers were not instructed of what to drink and how much to drink to aid rehydration after the weigh in. Due to the repeated high impact forces of repeated punching in boxing, we feel that dehydrating to a level of over 4% increases the risk of serious injury and something we have a duty of care to avoid. 

There are a variety of ways to induce sweat loss including the use of a sweat suit whilst exercising, sitting in a sauna or a warm bath. The scope of this article is to not recommend which method may be best or utilized. However, we do recommend in a method called water loading if you plan on dehydrating.

Reale et al. (2018) investigated the effects of increasing water intake by 100ml/ kg of body mass for 3 days followed by 1 day of reduced drinking of 15ml/ kg of body mass (see table 3 below). The authors assessed the effects on urine output, sweat loss and body mass. The group who water loaded compared to just drinking normally had a lower body mass, higher urine output and a higher sweat rate compared to just drinking normal (see figure 3). This is why we recommend water loading if you have over 5% to lose within a 7 day period. It seems that the less you drink, the harder it is to sweat and urinate due to being in a constant state of mild dehydration. This will make sweating harder when needed.

 A negative side effect of water loading is that you will be urinating more especially during the night. So we recommend that you load water earlier in the day and stopping drinking by 7pm. In addition, some people report dizziness with water loading, this is probably due to reducing sodium intake with the water loading. We would advise in still consuming a small amount of electrolytes when water loading if you do feel light headed and dizzy. Finally, we recommend you trialling water loading in training, before competition. We have seen some athletes who do not respond well whilst some do respond very well. Therefore, It needs to be used on an individual basis with professional help. Please, do not do this alone.

Table 3. Water loading example for a 62kg athlete.

Figure 3. Body mass, urine output and sweat losses between the water loading group and the control group from Reale et al. (2018).


We recommend starting fight week less than 8% away from your target weigh-in weight. If you are higher then we recommend you on fighting at a higher weight or avoid making weight for this fight. Your health is more important than any fight. If you are at 6-8% from your fighting weight, then we are confident that you can lose that weight by partaking in the following methods below if you have successfully followed the fight camp boxing diet outlined in part one.

  • Lower fibre intake (1%)
  • Lower carbohydrate intake (1%)
  • Lower sodium intake (1%)
  • Reduce food weight (1%)
  • Reduce water intake / passive sweating (3%)


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