While resistance training is essential for achieving your fitness goals, your diet is arguably just as important. A key aspect of your diet you should pay particular attention to is your protein intake. Consuming adequate protein each day is necessary to ensure proper recovery and building of new muscle following a workout.
Currently, the NHS recommends consumption of 0.75-1 g of protein per kilogram of bodyweight per day (g/kg/day). Whilst this may be enough for untrained individuals, for those who are active and perform regular resistance training sessions this will likely be insufficient. Additionally, the amount of protein you need seems to also be dependent on whether you want to lose, gain, or just maintain your weight, as well as the type of protein that you consume.
If your goal is to gain or maintain weight
For lifters who are either maintaining their weight or aiming to gain weight, the current evidence indicates that daily protein intake should be ~1.6 g/kg/day and up to 2.2 g/kg/day for those looking to maximise their gains (Morton et al., 2018).
So, to calculate your daily protein intake, multiply your bodyweight (kg) by 1.6 for the minimum intake, or multiply by 2.2 if you want to leave no doubt that you’re getting enough protein.
For example, a 70 kg individual should aim to consume between 112 g and 154 g of protein per day.
If your goal is to lose weight
For lifters who are in a caloric deficit and aiming to lose weight, daily protein intake will need to be higher to prevent loss of muscle mass during this period. Research suggests that protein intakes of ~2.3-3.1 g/kg/day are necessary to promote the maintenance of lean body mass when cutting calories (Helms et al., 2014). Beginner lifters who have a higher body fat percentage should target the lower end of this range, whilst leaner individuals with more training experience should aim for the higher end of this range.
For example, a 90 kg untrained individual with a high body fat percentage should aim to consume ~207 g of protein per day.
However, a 75 kg experienced lifter with a moderate body fat percentage should aim to consume ~233 g of protein per day.
What if you’re a vegan/vegetarian?
Whilst there is no doubt that you can achieve excellent results in the gym when on a plant-based diet, in order to maximise gains these lifters may need to consume more protein per day than those who consume animal products regularly. This is because the quality of plant-based protein sources is typically lower than that of animal-based protein sources, mainly due to lower digestibility of plant-based protein and deficiency in certain essential amino acids (Berrazaga et al., 2019).
Therefore, it is recommended that plant-based lifters target the upper end of the daily protein intake ranges previously mentioned. So, for those aiming to gain or maintain weight, a daily protein intake of ~2.2 g/kg/day may be optimal. And for those in a caloric deficit, a daily protein intake of ~3.1 g/kg/day will likely be sufficient.
Conclusion
Protein and resistance training go hand-in-hand, so if you want to maximise your progress in the gym you need to make sure your diet is geared towards helping you achieve your goals.
The optimal daily protein intake will vary depending on your goals, bodyweight, and diet. However, aiming for the higher end of the daily protein intake ranges mentioned previously might be the safest strategy to ensure that your diet is not holding you back. It seems logical that consuming slightly more protein than you need may be a better approach than potentially sacrificing gains due to not consuming enough protein in your diet.
References
Berrazaga, I., Micard, V., Gueugneau, M. and Walrand, S., 2019. The role of the anabolic properties of plant-versus animal-based protein sources in supporting muscle mass maintenance: a critical review. Nutrients, 11(8), p.1825.
Helms, E.R., Zinn, C., Rowlands, D.S. and Brown, S.R., 2014. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. International journal of sport nutrition and exercise metabolism, 24(2), pp.127-138.
Morton, R.W., Murphy, K.T., McKellar, S.R., Schoenfeld, B.J., Henselmans, M., Helms, E., Aragon, A.A., Devries, M.C., Banfield, L., Krieger, J.W. and Phillips, S.M., 2018. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British journal of sports medicine, 52(6), pp.376-384.
