From Plate to Waste: Investigating Dietary Protein Intake and Nitrogen Excretion in Vegetarians and Non-Vegetarians

The study compared dietary protein intake and urinary nitrogen excretion between vegetarian and non-vegetarian adults. Eighty healthy participants (40 vegetarians, 40 non-vegetarians) aged 20 to 50 years were randomly selected. Baseline anthropometric data were collected, and dietary protein intake was assessed using a 24-hour dietary recall. Participants also provided 24-hour food samples, analyzed using the Kjeldahl method, and 24-hour urine samples, analyzed for nitrogen excretion using the Pyrogallol red method. Data analysis was performed using IBM SPSS Statistics version 23.0, employing Chi-square, T-tests, and Mann-Whitney tests. Results indicated that vegetarians consumed slightly more protein (44.76 ± 21.54 g/day) than non-vegetarians (41.97 ± 21.44 g/day), meeting 74 and 60% of the recommended daily allowances, respectively, though this difference was not statistically significant (P = 0.568). Vegetarians also exhibited higher urinary nitrogen excretion (92.46 ± 55.69 mg/day) compared to non-vegetarians (78.96 ± 58.68 mg/day), which could be attributed to their increased protein intake. These findings emphasize the importance of ensuring adequate protein intake in both vegetarian and non-vegetarian diets and suggest further research is necessary to explore the health impacts of different protein sources.