ISSN Position Stand

The International Society of Sports Nutrition (ISSN) is the leading professional organization focused on the science of nutrition for athletic performance. Their position stands are consensus documents authored by leading researchers and updated periodically as new evidence accumulates. The current ISSN protein position stand recommends 1.4 to 2.0 grams of protein per kilogram of body weight per day for active individuals — roughly double the USDA RDA. For those in a calorie deficit trying to preserve muscle, the recommendation rises to 2.0 to 2.4 g/kg. These figures come from pooled meta-analyses of dozens of randomized trials in resistance-trained subjects. The ISSN also recommends spreading total intake across 3 to 5 meals, with at least 0.4 g/kg per meal to maximize muscle protein synthesis through the leucine threshold. Other recommendations include leucine-rich sources for older adults (who have anabolic resistance) and a reminder that total daily intake matters far more than exact timing. The ISSN position is what most evidence-based fitness coaches and registered dietitians actually use, even when general medical advice still defaults to the RDA. The protein calculator shows ISSN benchmarks alongside RDA and ACSM so you can see the gap.