The good news about fat loss is that billions of dollars are being spent on research and development in this area. However, there is bad news, as well. Millions of years of evolution are fighting against that research. These years of evolution have made the body very efficient at processing and using food, but it is all aimed at survival. Our bodies are programmed to store fat for survival.
In prehistoric times food was not always readily available, so the body had to become adept at storing energy for future needs. Often times a large animal would be killed for food and due to lack of storage capability the food had to be eaten, or go to waste. This massive influx of calories had to be stored for future needs, since it could be a long period of time before the next feast.
The body quickly recognized the easy processing of simple carbohydrates for energy. The protein needs of the body could easily be met by the meat eaten and then the protein could be excreted or converted for fat storage. Fats were very important for long term energy needs. When nomads traveled hundreds of miles between food gathering sites they needed lots of fats to fuel the aerobic energy cycle. The carbohydrates derived from fruits and grains were used for immediate energy needs and then any excess was converted for fat storage.
This system of storage was very efficient in times of feast or famine. It provided the energy needed to travel and hunt for food until the next feeding occurred. Unfortunately, today we do not need to hunt for our food and food is plentiful. Our bodies, however, have not adapted with this new change. We still store excess energy for future needs, even though we seldom enter a starvation state.
Another factor of this evolutionary development is the starvation effect. The body, striving for that survival again, slows the metabolic rate way down when it senses a reduction in calories or the start of a period of starvation. This reduces the amount of calories burned at rest, and even during activity. This was just another step in the survival chain to make sure there would be enough stored energy to meet future needs. Unfortunately, this makes the traditional diet difficult.
A calorie reduction diet works against this genetic preconditioning that has been developed over millions of years. Once you reduce your caloric intake your metabolism slows down to match it. It is simple survival. Even increasing activity, at least initially, is affected by this ingrained process. The common reaction to the slow down in metabolism is to reduce the calories further, which kicks the starvation response into overdrive, lowering the metabolic rate to rock bottom and reducing energy levels to prevent further calorie wasting.
Dieting is a billion dollar industry with products and research backed by science. However, fat storage is a deep-seated process backed by millions of years of evolution. This is not to say that fat loss is impossible, or should not be your goal, but simply to put in perspective the struggle we all face when it comes to long term success.