The phrase often refers to habits that increase urinary calcium loss or reduce absorption. First, high sodium: salty/processed foods can increase calcium excretion. Second, excessive caffeine—especially when calcium intake is low—can tilt the balance. Third, cola-type beverages and ultra-processed patterns may contribute indirectly. Fourth, absorption-limiting compounds: oxalate-rich greens (like spinach) and high-phytate foods can bind calcium, but this doesn’t make them “bad”—cooking methods, variety, and pairing strategies can help. Fifth, heavy alcohol use and smoking negatively affect bone remodeling. The strategy is practical: reduce salt, keep caffeine moderate, spread calcium intake through the day, optimize vitamin D, and maintain resistance training.