Are your habits healthy or are they killing you? Aside from cigarette smoking, which most people realize is deadly, there are at least four different common habits that could send you to an early grave. Here's a look at them.

Being Sedentary

Although physical activity might not be essential for weight loss, it is essential for good health. Several studies indicate that caloric restriction is more effective than increased physical activity, at least on the short term, for weight loss. But, the researchers have failed to look at the big picture.

Aerobic activity is good for the heart. It helps reduce stress, among other things. Strength building exercise adds muscle cells and tissues, which are more active. They require more calories simply to stay alive. Muscle cells are among the few that can choose to burn fat, rather than glucose. So, adding muscle is equal to subtracting fat.

Research indicates that regular physical activity, particularly weight bearing exercise, reduces the risk of osteoporosis. Osteoporosis is a degenerative condition that leads to bone loss and causes them to become more brittle, increasing the risks of fractures among the elderly.

Are your habits healthy if you fail to get some exercise every day? The simple answer is "no". Your body was designed to move and if you don't move it, you'll lose it.

Staying Up Too Late

Because of circadian rhythms, the human body was designed to sleep at night. Research indicates that working the night shift increases a person's risk of cancer. The evidence is strong enough that a European court ruled in favor of female night-shift workers with breast cancer, saying that the disease was work-related.

Are your habits healthy if you don't work at night, but you often stay up until 2 or 3 in the morning? No. If you miss out on sleeping between the hours of midnight and 3, you are missing out on the human growth hormone that your body produces during those hours.

If you consistently fail to get enough sleep, your body will produce more of the stress hormone Cortisol. Cortisol sabotages weight loss efforts and contributes to wrinkles.

Spending Too Much Time in the Sun

Skin cancer is still one of the most common forms of the disease, even though people have been told for years that overexposure to the sun causes it. But, are your habits healthy if you always wear sunscreen. Not necessarily.

For some reason, people that regularly wear sunscreen have an increased incidence of malignant melanoma, the most deadly form of skin cancer. Simply limiting time spent in the sun is the best choice.

Eating Simple Carbohydrates

Simple carbs, including breads, baked goods and sodas, impede weight loss and increase a person's risk of type II diabetes. Complex carbohydrates, which include most fruits and vegetables, on the other hand, are very good for your health.

Research indicates that the healthiest diet is one that includes lots of different fruits and vegetables, primarily because of the antioxidants they contain. So, are your habits healthy? If not, maybe you can change.