I lost over 50 lbs in 2018, and have muscle definition that I haven't had in over 30 years. Fitbit does help keep me moving, but it's important to understand that exercise is not the key to weight loss. It's what you eat, when you eat, and how often you eat.
As long as your insulin levels are high, you will gain weight, guaranteed, no matter how hard you exercise. Insulin is a fat storage hormone; you won't burn fat unless you bring it down! So yes, I do exercise every day, lifting weights and getting the most out of cardio sessions, I average well over 10,000 steps daily, and I make sure I don't get too sedentary (I work in ecommerce, it's easy to do this).
But the biggest difference has come from giving up starchy and sugary foods, eliminating nearly all processed and restaurant food, cutting alcohol to almost nothing, and fasting intermittently every week, PLUS moving more according to the principles of NEAT (non-exercise thermogenesis). Not exercising, necessarily. Just moving. Focus on your active minutes over steps.
You might try listening to The Obesity Code podcast with Dr. Jason Fung. It's free.
