For a 70-kg adult, a common safe target is ~0.5–1% per week, which equals roughly 1.4–2.8 kg over 4 weeks. With IF, success depends on maintaining balance in the eating window—adequate protein and fiber reduce rebound snacking that can erase the deficit. Track more than the scale: waist, energy, hunger control, sleep quality, and strength. Preserve lean mass with resistance training and sufficient protein. Aggressive rapid loss increases performance and sustainability risks; the evidence-based path is a consistent, measurable deficit and long-term habit building.