Pro Complex Gainer Weight Gainer Is the Powerful Macro Boosting Protein and, Pro Gainer contains 60 grams of protein and 85 grams of carbs in each serving. Naturally and artificially flavored. 650 Calories. 60 g Protein. 85 g Carbs. 25 Vitamins & minerals. The Bigger Picture Of Lean Gainers: Don’t judge a gainer based solely upon its calories per serving. Because when it comes to gaining lean mass, not all calories are created equally. Unlike typical weight-gain formulas that are loaded with simple sugars and fat, Pro Complex Gainer derives a much higher percentage of its calories from protein-7 premium protein sources to be exact.