150 Fat people can build abdominal muscles in a few days.
You can't build abdominal muscles in a few days, because fat can't be digested so quickly, otherwise your body can't bear it.
Through exercise, abdominal fat will remain 20% in about 3 weeks, and then abdominal muscles will gradually begin to appear after continuous exercise. After about 2 months, more obvious abdominal muscles can be seen.