There a literally thousands of articles and references about nutrition, diets and recommendations about what to do and not to do. A great deal of what is important is to look first at what the basics are and then try and apply the essentials of a healthy diet and nutrition to your personal genetic traits.
What further complicates this weight picture is that as we age, our metabolism and diet characteristics will absolutely change. A diet composition which may have been effective at maintaining a healthy weight at an earlier age or certain activity level is suddenly wrong because both the diet and activity levels have changed as we have aged or taken on a new job; or we are now suffering from an illness or injury which effects the amount of exercise that one may be able to do. People will typically put on weight because of an imbalance between the calories that they ingest and the energy (or calories) that they burn during the course of the day. This imbalance may occur because of a life long pattern of imbalance or because of some perturbation in this delicate balance. It may be related to ingesting more food than usual for any number of reasons, or a change in metabolism which means the body does not require the same amount of energy requirements during the course of a regular day. The problems arise because humans are creatures of habit and may have a difficult time adjusting or adapting to our body's new requirements (energy in: energy out). The difficulty is that if we do not become aware of the possibility that our balance is off, then a weight change (usually a weight gain) will occur.
The goal of this section is to educate people on how to acknowledge or understand that a change in dietary requirements or exercise levels is necessary as we age in order to undergo weight loss or maintain a stable weight. In order to do this, one must understand some basic and even some advanced concepts of nutrition.