A 56-year-old German Instagram personality, Sue Giers, shares her fitness and diet secrets for maintaining the metabolism and flexibility of a 26-year-old. She emphasizes starting the day with protein-rich savory breakfasts like eggs or cottage cheese to stabilize blood sugar, and prioritizing whole, anti-inflammatory foods such as grilled fish and vegetables. Giers also minimizes insulin spikes through practices like walking after meals and avoiding mindless snacking, attributing her youthful vitality to these cellular-level nutrition and fitness habits.