1. Your metabolism is adjusting to what you have.
Firstly, What is Metabolism? It is the body's ability to use various chemical processes to produce, maintain, and break down various substances, and to make energy available for cells to use. It will not burn what is designed to protect you, meaning those fats around your body.
The slower your metabolism is, the less food you’ll have to eat and the more exercise you’ll have to do to lose weight effectively. The faster it is, the more you’ll be able to eat and the less you’ll have to exercise.
2. You actually eat too little when it comes to calories.
When you starve yourself, you are not matching your calories to your activity. Your metabolism is going to do that one thing it's designed to do, which is to protect you, and slow down to help you maintain weight.
3. You are usually deficient in protein.
If you don't have enough protein to maintain your blood sugar, your body will steal protein from your muscles to fulfil the task. Therefore, people eating low carbohydrate diets probably need to increase their protein intake to maintain healthy blood sugar levels without losing muscle.
4. You forgot to include an important part of your exercise program - Lifting Weights.
Lifting weights help with performance and help maintain lean mass and functions. Muscle helps to burn fat as well.
When your metabolism is healthy–when you’re able to eat plenty of food every day without gaining weight–weight loss is very easy.