I answered this question on Quora, and it got upvoted, so I decided to share it with my readers here.
Member: National Weight control Registry5y
I’ll give my answer first, and then explain. I don’t think core exercises reduce belly fat, but I do think they can help the stomach appear flatter.
The muscles that affect the shape and appearance of the belly are the Transverse abdominis, Rectus abdominis, Internal and External obliques, and the Erector spinae.
When I was studying to be a Jazz dancer, I was taught to draw all of the core muscles toward my spine by pretending to “Zip Up” a tight jacket. Then, I was instructed to keep those muscles engaged as I moved.
As a personal trainer, I learned that exercises like the plank, stomach vacuum, and body saw, can train the core muscles to stay engaged during exercise and the activities of daily living. This helps us to maintain good posture, a healthy spine, and it even gives an energetic, youthful appearance.
Best of all, I believe that a strong core helps us to prevent injury, so that we can keep training. A good training program will help you develop muscle, or at least maintain it, if you are eating in a caloric deficit.
Speaking of a caloric deficit, although my clients and I have had success losing weight by reducing sugary and starchy carbohydrates, my experience makes me believe that a caloric deficit does matter for fat loss.
When it comes to food and fitness, I recommend that you ask yourself these questions: 1. How do I respond to this food? 2. How do I respond to this exercise? Be true to yourself, keep moving, and you will find what works.