When you eat carbs your body does a few different things with it. Carbs are converted to glucose. That glucose is then used for energy needs. What’s left over is stored as glycogen in muscle or liver. When you eat more carbs you burn more carbs but since you’re using more carbs for energy, less of your energy needs will be filled from other sources.
In the big picture, it’s irrelevant what your body burns during exercise. Your body doesn’t usually use a single energy source for anything. It’s mostly using multiple sources and it just shifts the favor to one side or the other. To lose weight, the bottom line is you need to eat less calories then your body used in a day. To minimize muscle loss and maximize fat loss, you’ll need to intake sufficient protein. Carbs can also help stave off muscle loss but that doesn’t mean you can’t cut fat efficiently with a low carb diet. Most ppl tolerate carbs just fine hence my general recommendation to eat as many as possible but still making sure to get enough protein and fat. If you don’t tolerate carbs well then you’ll be better off eating more fats and keeping carbs lower.
The first 10lbs you lost was primarily water and glycogen. If after another week or two you get no additional weight loss then it’s time to reduce calories further and/or make sure you’re weighing and tracking your intake properly.
