Do ab exercises make your stomach look bigger if you have some fat?
If you strengthen your abdominal muscles and do not lose weight then it is likely that belly fat could be pushed out by the muscle growth and make your abdomen appear bigger . This can also be true if you are doing heavy exercises for your obliques. These exercises can make you look more trunk like with a wider waste.
Doing heavy abdominal exercises can cause temporary swelling to the abdominal area because of the tiny muscle damage that occurs after heavy exercise.
Don't mistake skin looseness for new fat. When I really started to do core exercises, The muscles of my abdomen became very strong, but my deflated stomach fell all around my middle. When I sat down, I looked like a pile of mashed potatoes. As I continued to lose fat (and my skin caught up), this went away and I was rewarded with a slimmer midsection. This process can take longer as we get older and extreme weight loss may leave permanently loose skin without surgery.
planks and core exercises are what are currently favored over crunches. Developing your stomach muscles will pull in visceral fat.
If you have weakened and stretched stomach muscles, like after the birth of a child, then stomach exercises will simply pull in the muscles tightening them up. But take it easy directly after childbirth and take special care following a c-section, consult your doctor first.