The first and most important reason why you are not burning fat is because you are eating too many calories. Plain and simple the only way to lose body fat is to be in a caloric deficit. You need to be expending more calories than you take in. A lot of this has to do with calories that you don't notice.
Muscle is denser than fat.
While one pound of fat weighs the same as one pound of muscle, muscle occupies about 18 percent less space. In addition, muscle burns calories while fat stores them. So, if your weight isn't decreasing but your clothes are starting to fit more loosely, you may be building muscle.
Mostly, losing weight is an internal process. You will first lose hard fat that surrounds your organs like liver, kidneys and then you will start to lose soft fat like waistline and thigh fat. The fat loss from around the organs makes you leaner and stronger.
You can't lose weight on 1200 calories a day because you're no longer in a calorie deficit. Your body has adapted to what it's been doing and plateaued. If you start your diet with a 500 calorie deficit per day, your body adapts to this in various way so that over time your energy requirements are reduced.
You're eating too much during your eating window.
“If you end up consuming the same number of calories (or more) during your eating windows as before you started intermittent fasting, then you won't lose weight.”
Unhealthy eating is the biggest driver of big bellies. Too many starchy carbohydrates and bad fats are a recipe for that midsection to expand. Instead, get plenty of veggies, choose lean proteins, and stay away from fats from red meats. Choose healthier fats in things like fish, nuts, and avocados.
High-intensity interval training (HIIT): It is probably one of the fastest and most efficient ways to lose stomach fat and reduce the overall body fat percentage. HIIT is a high-intensity short period of exercise that usually doesn't exceed 30 minutes, with short breaks of recovery periods of 30-60 seconds.
The most effective exercise to burn stomach fat is crunches. Crunches rank top when we talk of fat-burning exercises. You can start by lying down flat with your knees bent and your feet on the ground.
You've Gained Muscle Mass
If you're exercising regularly and doing a mix of cardio and strength training, it's very likely your body composition (ratio of muscle to fat) is changing for the better. If you're gaining muscle while losing fat, the scale may not show any weight change.
YOU'RE NOT EATING ENOUGH DURING YOUR WINDOW
You'll be so hungry, you may start eating and not stop. As well, the body stores food to protect itself. Your body will sense the need to stock up on reserves and may store those extra pounds as fat instead of lean muscle.
Calorie intake: Your Eating too much or Not Enough
A HUGE factor that plays into your intermittent fasting results is how much you are eating. It can go both ways, eating too much or not eating enough - both have negative effects on your results and could be why you aren't seeing results with intermittent fasting.
Lummus says that when your body goes into starvation mode, your metabolism slows to a crawl, burning calories as slowly as possible to conserve its energy stores. This is why people who cut their calories too much may reach a plateau and stop losing weight.
Start your diet by setting your calorie deficit at 20-to-25% (eat 20-to-25% fewer calories than you burn every day). Once you stop losing weight (and you've already tried the other strategies in this article) reduce your daily energy intake by 100-to-150 calories per day (take them all from carbs).
In terms of how your body looks, “it usually takes 4 weeks for your friends to notice weight loss, and 6–8 weeks for you to notice,” says Ramsey Bergeron, a certified personal trainer. “Your friends who don't see you every day are much more likely to see a change than someone you're around all the time,” he adds.
Running is the winner for most calories burned per hour. Stationary bicycling, jogging, and swimming are excellent options as well. HIIT exercises are also great for burning calories. After a HIIT workout, your body will continue to burn calories for up to 24 hours.
Aerobic or Cardio Exercise
Some great cardio of aerobic exercises for belly fat include: Walking, especially at a quick pace. Running. Biking.
6. Sprinting. The best cardio for belly fat loss is Sprinting. Whether on the treadmill or outside, sprints are a great way to burn the most calories in the least amount of time.