I am a 30-year-old, 5'8" male. I started off at 140 lbs now I am hovering around 133.4 lbs. 130 lbs is my target weight. I don't want to lose any weight after that. I am already looking skinny overall, but my belly fat hasn't decreased even a bit. For my height and age, I can only lose 9 more pounds before being considered underweight. According to this calculator
This is what I am eating every day:
Breakfast
1 packet of oats, 1 tsp sugar, 2/3 cup milk
Calories: 200
Lunch and Dinner
Indian curry + 1/3 cup rice(measured before cooking) + 1 tbsp Indian pickle
Calories: 600
All in all my total calories intake per day is 1400.
Excercise
Once a week, I lift weights for an hour, I ride the exercise cycle for half an hour. I can visually see that I am gaining muscles. My biceps, calf muscles, chest area, shoulders and back all look thicker and a tad bit muscular.
According to this calculator, I should be losing around 1 lb of fat per week. And I have been losing 1 lb of fat per week as expected. But I haven't lost a single of my belly fat.
Also, my weight goes up drastically even if I eat let's say roughly 300 to 400 extra calories just one day out of 7 days. So I have a feeling that the weight I am losing is not permanently lost. What can I do to fix this situation?

