Mass Gainers are developed specifically for slim men
https://www.scribd.com/document/534775459/391095What-skinny-individuals-need-to-know-about-Mass-Gainer-and-also-exactly-how-it-can-help
Mass Gainers are designed particularly for skinny men who want to pack on muscle mass swiftly without getting fat along the road. These products have additional calories from healthy protein and carbs mixed in