You haven’t dramatically changed how you eat, but suddenly your jeans fit differently. Your waist seems thicker, weight is settling around your middle, and the things that worked in your 20s and 30s don’t seem to work anymore. If you’re wondering, “Why is my belly getting bigger after 40?” you’re certainly not alone.

If you feel like you’re doing everything “right”—eating healthier, exercising more, cutting calories—and the scale still isn’t moving, you’re not alone. Weight loss is often treated like a simple equation: eat less and move more. But for many people, the reality is much more complex. Your body is influenced by hormones, metabolism, sleep, stress, nutrition, body composition, digestion, and other internal factors that can make losing weight more difficult—even when you’re putt