Because thin females and muscular males are seen as the ideal in our society and because we have come to believe that body size and shape are totally under a person's control, most people enter diet and exercise programs with unrealistic goals and expectations. If you continually strive to achieve a socially imposed ideal, you will never be free of your insecurities or your self-consciousness. You must truly realize and then learn to accept that we are not all meant to be fashion-model size.

Our body size and structure reflects not only our eating and exercise habits but also our genetics. The role this latter factor plays in determining weight seems to vary greatly between individuals. We are all born with a certain body type inherited from our parents. Although hardly anyone is a pure body type, there are three different applicable categories: ectomorphs, mesomorphs, and endomorphs.

Characteristically, ectomorphs have a light build with slight muscular development. They are usually tall and thin with small frames and narrow hips and shoulders.

Mesomorphs have a husky, muscular build. They often have broad shoulders, and their weight is concentrated in the upper body, making them look compact or stocky.

Endomorphs are characterized by a heavy, rounded build with shoulders usually narrower than their hips. They have a round, soft appearance and are more often overweight or obese.

When we understand and appreciate our bodies, we are able to work with them, not against them. Although many of us are a combination of two body types, we cannot become what we are not. However, everyone can improve their appearance and their health and performance levels by implementing the principles of a safe and effective eating and exercise program.

Even if you have a genetic predisposition to being overweight, the way you live is what ultimately determines whether you become fat. Genes clearly play a role, but they certainly don't determine what you're going to have for dinner or how often you exercise. Chances are if you're living an unhealthy lifestyle, you'll become fat and unhealthy.

All of us can't be thin. But every single one of us can be healthy. By focusing on what you're eating and how much you're exercising, you'll be able to achieve optimum health and fitness, even though you may not achieve society's ideal of thinness. Accepting yourself does not mean that you're hopeless and that it's okay to do nothing. It means that you feel good and care about yourself, and that you want to be the very best you can be, regardless of your genetics, regardless of society's standards.

To achieve this level of optimum wellness, you must have a positive self image. This means that your feelings about your body are not influenced by events in your daily life. For many people, life's problems are projected onto their body. "If only I were thinner--or more muscular, I would have made the team, gotten the job, been chosen. . . . If only I were thinner--or more muscular, I could meet more people, find the right guy/girl, be happy." This self-defeating habit is reinforced by the images we see in advertising; your body becomes an easy target for everything wrong in your life.

When you have a positive self-image, you value and respect your body; you are also more likely to feel good about living a healthy lifestyle.

No matter how much genetics predetermines how you store and lose fat, the body you've been given will still respond positively to being appreciated and treated well. Focusing on fun physical activity and eating healthy foods will help you feel good whatever your size. Developing a healthy, positive image of yourself is the first critical factor in your fitness success. Having a strong sense of self-worth provides the basis for making rational and affirming decisions about your health. Good luck, stay positive, and enjoy all the wonderful benefits of a healthy, active lifestyle!

Chad Tackett is President of Global Health & Fitness. Learn how you can have your own personal online trainer, dietician and motivator at http://www.global-fitness.com