The human brain utilizes more energy than any other organ in the body. About 1/3 of its energy is used for maintaining cellular health and 2/3rds to provide energy to fuel neurons so they can communicate with one another. This energy needed represents about 20% of our resting metabolic rate.
Using some of the brains energy to think about gaining and losing weight, it is understood if you eat more calories then you expend you will gain weight. If you create a negative caloric balance or deficit your body will burn it's stored fat for energy and ultimately you will lose the desired poundage that you wish. Counting calories is certainly away to track what is happening when you diet, using dietary software, dietary programs, exercise wrist watches all help. Even with technology and professional dietary programs science says the relationship of counting calories and managing body weight is not as simple as one may think adding to what we already know, that diets, even with the appropriate caloric balance are frustrating.
Let's say, at the time you are 'moderately active' and begin precisely monitoring calories as you up your activity level to 'very active'. The goal is to increase energy expenditure by exercising more while keeping your food intake consistent. This should cause you to lose pounds. Having a new high energy level and watching your diet may initially give you your desired weight reduction, but other things begin to occur. Becoming more fit causes you to relax more completely, you also may nap and sleep through the night soundly. These positive outcomes of becoming in better shape and conserving more energy through rest, can reduce caloric needs. Suddenly the amount of calories from the food that you are taking in is reflective of the caloric needs of being 'moderately active' and the new activity adjustment no longer reduces your weight. The good news is that what is occurring fitness wise is certainly a plus.
There is another caloric expenditure occurrence that happens as you become more fit that changes energy requirements. Becoming more active leads to becoming stronger and more skilled in movements which gives you what is deemed better economy of motion. This new economy of motion decreases your energy expenditure to perform the athletic skills that you are doing and also decreases the total caloric needs for daily tasks such as stair climbing, walking and a host of other normal activities above your basal metabolism.
Once you begin adding muscle due to your new 'activity level' change - caloric needs once again are modified. Gaining muscle requires additional calories each day to gain and maintain mass. Keeping the number of calories consistent to lose body fat becomes tricky as muscular gains are also an important part of fitness and require a caloric increase that you are trying to avoid.
The bottom line is - all diets have their ups and downs and require adjustments, patience, determination and consistency which are a must if you want to Get Lean and Get Strong.