Muscle growth at risk
In bodybuilding, a large amount of protein is often consumed to build muscle. A study now shows that this can lower testosterone levels in men.
Worcester (England). In bodybuilding, high protein intake is considered essential for building muscle. A new study from the University of Worcester now shows that a high-protein diet in men can lower testosterone levels and thus promote muscle growth. According to the publication in the Journal of Nutrition and Health, nutritionist Joe Whittaker’s team found this in a study in which they examined the testosterone levels of 309 men for two months.
Study subjects ate a diet consisting of 35 percent fish, meat, and protein shakes. This contained between 185 and 215 grams of protein per day. 185 grams of protein is equivalent to 1 kilo of salmon, 2.26 kilos of chicken or 29 to 35 eggs, according to data from the United States Department of Agriculture. At the end of the study, the subjects’ testosterone levels were on average 37 percent lower. In addition, many participants suffered from symptoms associated with low testosterone levels, including fatigue, erectile dysfunction, depression, and muscle weakness.
Double Protein Intake
Protein intake during the study period was twice the average protein intake for men, according to nutritionist Erin Coleman. Nutritionist Bonnie Taub-Dix also stated that she believes that a diet that is too high in protein can cause low testosterone levels. However, this is only the case for people who consume excessive amounts of protein to build muscle faster.
It should be noted that the University of Worcester study only had a relatively short observation period. In addition, other factors that can influence testosterone levels besides diet, such as the lifestyle of the test subjects, were not taken into account.
Journal of Nutrition and Health, doi: 10.1177/02601060221083079