Belly fat

Calories are the direct influence on weight management (fat gain/loss), not nutrients (macro or micro).

Sure, nutrition can have an indirect effect on weight: If we eat sub-optimally enough, we can experience low energy, so rest more and burn fewer calories than expected. Or, sub-par nutrition can trigger appetite/cravings, making it difficult to stick with a sensible calorie level.

The direct effect on body weight (fat weight) is still calories.

Suggestion: Log foods you like to eat, things you find convenient and affordable. Adjust to meet a sensibly moderate calorie deficit. When you do that, do you feel reasonably full and happy most of the time (maybe getting hungry as a mealtime approaches)? If so, you're golden on the weight management front: That will lead to weight loss.

If you don't feel reasonably full and happy most of the time, experiment with different foods (ones you like OK) or timing of eating to find a better state. Get that into place, cemented into your routine habits.

Nutrition is important, but it's important for things like health, exercise performance, energy level, body composition (muscle vs. fat), etc.

Once you have your calories and satiation in pretty good shape, there'll still be plenty of time to tweak your eating habits to get better nutrition, if you want to do that.

You can do that by looking back at what you've logged, and noticing what nutrients you may be short on most of the time on average. Then find some foods that are costing you quite a few calories, but that don't feel worth it for what they give you (nutrition, satiation, tastiness, etc.). Reduce or eliminate those foods, replacing those calories with foods you like that better help you meet your nutritional goals.

That'll work fine.

Best wishes!