Protein: How Much?

Whilst the government recommend a minimum protein intake to be 55.5g/day (15% of energy intake), this is aimed for the ‘average’ person, not an athlete who trains 2+ hours of resistance training each day (Gov UK, 2016). As a result of this, this athlete’s protein intake appears preposterously high at a 174.1g/day (2.1g/kg), making up 21% of total energy intake. However, Millward stated that protein and calorie intake hold an inverse relationship, with protein becoming more important when calorie intake is low (2004). Furthermore, Layman expressed that protein needs are functions of lean mass and must increase as a percentage of low-calorie diets (2009). Whilst our athlete’s calorie intake is not necessarily low, being 3311kcal/day, they are still in a caloric deficit, giving reason to their high protein intake. Compared to other body builders, our athlete is slightly above the normative protein intake of 163.4g, but this is to be expected when in a ‘cutting’ phase due to the previously mentioned relations of protein and calorie intake (Ismaeel et al.,2017).

Physiology Behind Protein:

Amino acids, known as the building blocks of protein, provide metabolic responses to protein synthesis but also have positive affects on other metabolic roles. For example, protein increases cell signalling, satiety, thermogenesis, and glycaemic regulations (Layman, 2009). Post-exercise, both muscle protein breakdown and muscle protein synthesis are increased, with studies showing the consumption of amino acids after exercise can turn this balance in favour or protein synthesis. Evidence suggests hyper aminoacidemia can also be effective in maximising this anabolic response (Tipton et al., 1999). A meta-analysis showed that protein consumption timing has a slight, yet positive, effect on muscle hypertrophy when consumed just before and shortly after resistance training. However, it was noted that quantity of protein consumption was more important than the timing, in terms of hypertrophy (Schoenfeld et al., 2022).

PLANT BASED PROTEIN (PB)

There has always been a large amount of doubt surrounding plant-based protein and its health effects. As with any diet there are pros and cons. We all know that protein is key for bodybuilders and getting enough form plant based foods can sometimes be challenging as they are less readily available. While PB proteins do have less essential amino acid content, they have a very large variability in amino acid composition and are still complete proteins (Gorissen et al., 2018). Each source is very different so having a wide range in your diet is key and as you can see, our athlete manages to even exceed protein goals while on a PB diet.

 

Carbs: How Much?

Current UK guidelines on carbohydrate

intake is 333g/day, making a total of 50% of dietary intake (Gov UK, 2016). Sitting slightly under the guidelines, our bodybuilder consumed 349.1g in this specific day, making up 42.2% in total energy intake. Research varies on how much carbohydrates bodybuilders should consume, with some favouring a higher percentage and some favouring a lower. Ismaeel et al, found that bodybuilders have a normative carbohydrate intake of 323.3g, making up approximately 48% of total energy intake (2017). This puts our athlete within normative ranges. Carbohydrate intake is set to change depending on how far into pre-competition the athlete is, with some using a depletion and loading phase in the days leading up to competitions. This technique, while not always advised, has shown a 3% increase in upper arm size (Escalante et al., 2021).

 

High carb:

Some people advocate high carbohydrate intake in bodybuilders, higher than even government guidelines. For example, one study suggested that both in the pre and offseason, competitive bodybuilders should have a carbohydrate intake of ~55-60% of total energy intake so they are fuelled enough to maintain training intensity, even in a calorie deficit (Lambert et al., 2012). The goal of the pre-season bodybuilders is to reduce bodyfat whilst maintaining muscle mass. Usually, this is achieved by maintaining resistance training intensity whilst increasing cardiovascular exercise and lowering caloric intake. Having a high protein intake (~30% of energy) whilst in a negative energy balance (~15%) will oxidise fat whilst maintaining as much lean mass as possible (Lambert et al., 2012). But without this increased amount of carbohydrates, the bodies main source of energy, both anaerobic but mostly aerobic exercise will become increasingly difficult. Endurance performance and capacity are heavily influenced by carbohydrate availability (Cermak and van Loon, 2013).

Low carb:

On the other end of the spectrum, some prefer a lower carbohydrate diet. One study noted that diets consuming 7.7g/kg/day for 48hours before a training session had no greater impact on performance than those consuming 0.37g/kg/day (Iraki et al.,2019). Low-carb diets can cause a reduction in levels of plasma insulin, which drives to store fat within adipose tissue, resulting in a progressive loss in body fat (Barber et al., 2021). To conclude, there is little evidence supporting very low carbohydrate diets in the sport of body building, for the most part an adequate carbohydrate intake of at least 3g/kg/day is needed for the intensity of work (Iraki et al., 2019).

Carbs with Protein:

Evidence strongly suggests that the consumption of carbohydrates with the post-workout protein has a positive anabolic effect on muscle growth. Carbohydrates increase insulin levels, promoting glycogen restoration and optimizing hormonal environments to serve as stimulation for protein synthesis pathways, showing the most benefit when 1.2g/kg is consumed at 30-minute intervals (Kreider et al., 2022; Ivy, 2001). Whilst muscle hypertrophy is not the primary goal for our bodybuilder during this pre-competition phase, this increased anabolic effect can further improve the protein synthesis/ breakdown relationship in a positive manner, aiding in the maintenance of lean mass during the calorie deficit period.

 

FATS

Fats: How much?

Dietary fat intake is recommended to amount to 35% of total energy intake, with 11% coming from saturated fats, 6.5%

from polyunsaturated fats, and 13% from monounsaturated fats (Gov UK, 2016). Our bodybuilder had a fat intake of 135g, comprising 36.8% of energy intake. Whilst this is on par with the guidelines, most bodybuilders follow a high-carb, high-protein, low-fat diet. One study even suggest that bodybuilders should have a dietary fat intake of ~15-20% of total energy. The reasoning behind this is that excess saturated fat can increase the risk of disease, such as coronary artery disease, but it is also warned that a dietary fat intake too low can negatively effect testosterone levels (Lambert et al., 2012).

Fat is an essential nutrient for vegetarian bodybuilders as it aids in hormone production, energy storage and nutrient absorption. Although PB diets naturally provide fats form sources like nuts, seeds, oils and avocados, it is important for vegetarian bodybuilders to make sure they satisfy their fat requirements for optimal performance and muscle growth. Incorporating a variety of healthy fats into the diet can support this. However, it is essential to be mindful of the type and volume of fats consumed as some plant-bases sources may be high in saturated fat or trans fats which can negatively impact cardiovascular health. Additionally, vegetarian bodybuilders should monitor their omega 3 fatty acid intake as plant-based sources like flaxseeds, chia seeds and walnuts may not provide sufficient amounts of nutrients found in fish oils. Using supplements with algae based omega 3 may be necessary. Overall, while plant-based diets can provide ample healthy fats, those on the diet need to consider potential limitations and considerations to support their training goals and overall health. (Venderley and Campbell, 2012, Vigor et al, 2020, Amitori et al 2023).