Some body builders follow a diet of 300+ grams of protein (1.5-2g/lb of body weight), without much consideration of the other nutrients like fat and carbohydrates, vitamins and minerals, or metabolism and excretion — as long as they get “enough” protein. The opposing view is that consuming more than 0.35-4g/lb of body weight can harm the kidneys, cause cancer, or lead to osteoporosis – but are these scientifically valid concerns?
Take a 180-lb man for example: his recommended intake could range from 63g to 360g, depending on who you ask. Body builders oftentimes consume loads of protein in hopes of bulking up. Skeptics warn that consuming so much protein is toxic to the system. So who is right?
Usually, neither of them.
Proteins consist of amino acids that are the building blocks of muscles, bones, and many hormones. However, most of us, especially those trying to gain muscle, are taking too much protein. Consumption of protein affects not only the muscles, but the other tissues and organs. Excessive protein can lead to weight gain, stressing the kidneys, and dehydration.
So how much do you need? Check your lean body mass. If you have 20% body fat, you have 80% lean body mass. Multiply your weight (kg) by 80% (0.8) to obtain your target protein intake. If you weigh 180 lbs (~82kg), your daily protein intake should be ~65g.
While animal proteins do provide a complete spectrum of amino acids, plant-based proteins also have amino acids. Some studies have suggested that diets high in animal protein (not just processed meats) can lead to higher cancer rates. Be sure to have a balance of both high-quality animal- and plant-based proteins.
Photo credit: A range of protein-rich foods.18 October 2014, 15:17:14. Own work by Smastronardo