Aside from genetic factors and pathological reasons, simple obesity is actually the corresponding relationship between energy intake and consumption. Intake is greater than consumption to get fat, and consumption is greater than intake to get thin. Soy sauce soup also contains a certain amount of calories. If you eat three meals normally and drink soy sauce soup at the same time, it will only increase your energy intake. Of course, if you only drink miso soup every day and don't eat other foods, you can actually reduce your energy intake in theory, but it is not good for your health because of unbalanced nutrition.
The ideal way to lose weight is reasonable nutrition, reducing calories and increasing exercise.