You work out regularly and follow a clean, healthy diet, so why is your belly fat refusing to budge?  Firstly it’s important to understand that there are 3 types of abdominal fat: 

 1.) Visceral fat: This protects and supports the organs within the body and makes up the majority of your belly fat. It is the type of fat that, in excess, can lead to cardiovascular disease.

2.) Subcutaneous fat: This is deep below the skin; usually found in large amounts on the hips, thighs and buttocks. This is the second most dangerous fat as it poses a much lower risk of chronic health problems than visceral fat.

3.) Intramuscular fat: This is not common in the abdominal area, but can be found within the abdominal muscles. Excessive amounts of this can be linked to a higher risk of diabetes. 

Now, Here are reasons why u r not losing belly fat  

1.) You're Doing the Wrong Workout Many people assume that the quickest way to burn belly fat is by doing insane amounts of crunches or sit ups. This won’t work. Yes crunches will strengthen your abs, but you will still be left with the layer of fat over them. A combination of cardio and weight training is the best thing for burning fat and, although it’s very difficult to spot reduce fat, weight training will make your metabolism speed up resulting in your body burning fat at a quicker pace all over.  

2.) You're eating too many processed foods "Refined grains like white bread, crackers, and chips, as well as refined sugars in sweetened drinks and desserts increase inflammation in our bodies,"  "Belly fat is associated with inflammation, so eating too many processed foods will hinder your ability to lose belly fat.". Natural foods like fruits, vegetables, and whole grains are full of antioxidants, which have anti-inflammatory properties and may therefore actually prevent belly fat. 

 3.) Your workout isn't challenging enough To banish stubborn belly fat, you have to ramp up your workouts. In a study published in the journal Medicine and Science in Sports and Exercise, people who completed a high-intensity workout regimen lost more belly fat than those who followed a low-intensity plan. (In fact, the low-intensity exercises experienced no significant changes at all.) 

"You need to exercise at full intensity because the end goal is to burn more calories, and high intensity exercise does just that. High intensity workouts mean you're going all out for as long as you can. If this sounds intimidating, think of it this way: you'll burn more calories in less time.

  4.) You're stressed Tight deadlines, bills, your kids—whatever your source of stress, having too much of it may make it harder for you to drop unwanted pounds, especially from your middle. And it's not just because you tend to reach for high-fat, high-calorie fare when you're stressed, though that's part of it. It's also due to the stress hormone cortisol, which may increase the amount of fat your body clings to and enlarge your fat cells. Higher levels of cortisol have been linked to more visceral fat.  

5.) You aren’t getting enough sleep We are all guilty of this one. With busy lives it’s often difficult to get as much sleep as we know we should, but our bodies need it! Sleep deprivation can cause you to pile on the pounds, and there has even been research that has found that the biggest spike in fat burning hormones occurs during deep sleep.  Sleep deprivation is also well known to increase stress levels, resulting in increased cortisol levels, which affect your fat loss (as explained earlier). 

 6.) Your Diet is Packed with Salt If you've ever felt bloated after a salty meal, it's not in your head. Excess salt causes water to move from your bloodstream into your skin, which will give you a puffy look. Nearly 90 percent of people consume more than the recommended 2,300mg sodium per day. So even if you're not pouring on the table salt, you're likely getting more sodium than you need through other sources such as canned foods, salad dressing, deli meats, and even some dairy products like cottage cheese.  Flat-belly solution: Avoid adding salt to your meals. Instead, boost flavor with spices and herbs, many of which have added health benefits as well. Try cooking with delicious flavors like cinnamon, chili powder, cayenne powder, cumin, ginger, basil, parsley, and rosemary—we promise you won't miss the belly-bloating salt.