• According to a research report published by Cardiff Metropolitan University, the protein requirements for the general population are 0.8-0.9g/kg/day, while the IOC sets the level of protein consumption for athletes at 1.8g/kg/day. The study which was published in 2018 claims there is no current guideline for the average gym goer.
• The above study of 65 non-athlete male gym goers found that the average protein intake for the group was 2.48g/kg/day.
• Another study published in 2016 found that a new method of determining protein requirements, called indicator amino acid oxidation (IAAO), showed that minimum protein requirements had been underestimated by 30-50%. This study recommends protein intake of 1.5 to 2.2 g/kg/day.
•  This study appears likely to have useful information related to protein consumption and building muscle, but it was paywalled.
• This study indicates that athletes are generally consuming much higher levels of protein than what is recommended, but the details were behind a paywall.
• Another consideration for consuming protein to build muscle, is how the consumption should be distributed throughout the day. The study concludes that consumption should be between 0.4g/kg/day per meal and 0.55g/kg/day per meal for a total of four meals. This would result in a total between 1.6g/kg/day and 2.2g/kg/day.
• According to Healthline, the right amount of protein depends on factors including "activity level, age, muscle mass, physique goals and current state of health."
• Healthline also attempted to determine an estimate of the proper protein range based on reviewing several studies on the topic. Their recommended range based on the review was 1.6-2.2g/kg/day (about 0.7-1 g/pound/day).
• According to Men's Health, the best way to calculate protein needs is based on lean body mass. Most research indicates that is "little benefit to consuming more than 2.2g of protein per kg of lean body mass."
• Lean body mass is calculated by multiplying weight times 100% minus percent body fat. "If you weigh 90kg with 20 per cent body fat, you have 72kg of lean body mass."

Summary of Findings

• In our initial research we were able to find a general recommendation on how much protein to consume for building muscle. While it was not found specific to a male in his 30s, our research indicates that this data may not be publicly available, as seen by the paywalled studies that were found.