When you lose weight, your body fights back. Here are 12 reasons why you're not losing weight:

1. You're Not Keeping Track of What You're Eating - Keeping a food diary can be helpful when you are trying to lose weight.

2. You're Not Eating Enough Protein - Protein is the single most important nutrient for losing weight. A high protein intake also helps prevent metabolic slowdown, a common side effect of losing weight. 

3. You're Eating Too Many Calories - If you are not losing weight, you should try weighing your foods and tracking your calories for a while.

4. You're Not Eating Whole Foods - Food quality is just as important as quantity. Eating healthy foods can improve your well being and help regulate your appetite.  Eating too much processed food could ruin your weight loss success.

5. You're Not Lifting Weights- This can help you maintain muscle mass, which is often burned along with body fat if you are not exercising.

6. You're Binge Eating - Binge eating is a common side effect of dieting. It involves rapidly eating large amounts of food.

7. You're Not Doing Cardio - It is one of the most effective ways to improve your health. It is also very effective at burning belly fat, the harmful "visceral" fat that builds up around your organs and causes disease.

8. You're Still Drinking Sugar - Avoiding all sugary beverages is an excellent weight loss strategy. 

9. You're Not Sleeping Well - Good sleep is one of the most important factors for your physical and mental health, as well as your weight. Lack of quality sleep is a strong risk factor for obesity. 

10. You're Eating Too Often - One effective weight loss method called intermittent fasting involves deliberately going without food for extended periods of time (15–24 hours or more).

11. You're Not Drinking Water - Drinking water can benefit weight loss. To reduce your calorie intake, drink a glass of water before meals. Drinking water can also increase the number of calories you burn.

12. You Have a Medical Condition - There are some medical conditions that can drive weight gain and make it much  difficult  to lose weight.

Such as hypothyroidism, polycystic ovarian syndrome (PCOS) and sleep apnea.

Certain medications can also make weight loss  difficult or even cause weight gain.

Dieting is not a long-term solution. If you wish to lose weight and keep it off in the long term, focus on adopting healthier lifestyle habits.