OK, my muscles are not so even and I can only count 4 packs, but at least, they are showing! But they tend to disappear and reappear. But I have made some analysis and research on why they disappear and the remedies to bring them out again. My findings are summarized below:
Type 1: Flabs
This would include love handles and muffin tops. Basically, the skin around the navel becomes soft and flabby.
Cause: Over-consumption of oil, sugar and carbohydrates.
Remedy: I reduce my food intake and increase turbulence and interval training, and drink more water.
Type 2: Protrusion
The navel area becomes protruded or distended. Noticeable sideways. I can still see ab muscles but the are bulges out.
Cause 1: Too much lower-abdominal exercise on the gut area, resulting in muscles expanding in the gut area.
Remedy 1: I just reduce the gut exercises for the day.
Cause 2: Hot air resides there, in the small/big intestines. This would be due to access body heat or eating the wrong food that gave me some flatulence.
Remedy 2: I just need to do interval training to sweat out and release hot air. Farting and pooping will help, from my observation.
Cause 3: Waste matter stuck there, as a result of over-eating, wrong eating times, eating wrong food
Remedy 3: Taking probiotics to help get the waste matter out and changing lifestyle a bit (or a lot)
Type 3: Blanket
The muscles on the top part of the abs, above the navel, start to become invisible and the skin becomes thicker. AKA blanket covering the abs.
Cause: too much sugar or having less exercise.
Remedy: doing interval training, sweating, working out in the morning, reducing sugar.
Please note that the above findings are ways that can help me get my ab muscles to show and not a generic way for everyone to really get ab muscles. I already have ab muscles and this is "maintenance". If you have not or have just started your road to ab muscles, then you should start from beginning; a complete lifestyle overhaul and workout session. Using my ways above may or may not work for your case...