You follow any type of diet plan, you need to know how many calories you are getting. Basically calories come from fats, proteins and carbohydrates. Various diet plans work on the basis of variation in these 3 nutrients. If you are on low carb diet, you tend to increase proteins and fat. In case of Mediterranean diet they increase fat percentage.
In following video it is discussed in detail. How many calories you get from carbs, proteins and fats. You can also check this short video to understand how to plan your weight loss meal plan.