Environmental Factors,Causes of Obesity

Along with genetics, environmental factors have been found to contribute to obesity. In particular, increased food consumption and an inactive (sedentary) lifestyle are environmental factors that very closely correlate with an increased risk of obesity. Americans have an ever-increasing number of energydense foods, packaged in enormous portions, conveniently available at low cost. Energy-dense foods contain large numbers of calories in very small portions. These foods promote the overconsumption of calories. Americans also consume 40% of their calories from fats, which is well above the level recommended by the American Heart Association (AHA). Fats are an extremely energy-dense form of nutrition. The AHA recommends that adults obtain less than 30% of their daily calories from fat. In the United States and in other developed countries, modern technology allows people to be less active in their daily tasks, since many things today are automated and do not require manual labor. For example, years ago people walked to most places. Today, people have access to cars and public transportation to take them to these same places, thus limiting the need for physical activity.
Decreases in physical activity can lead to weight gain. Ultimately, all the calories you eat are not utilized, or burned off. Calories that are not utilized are stored as fat tissue, which can lead to weight gain. Sedentary behavior is on the rise now that technology and automation are so widely available. All of the modern conveniences we now have accessible to us have eliminated the need for individuals to perform much of the physical activity that was once required for daily tasks at work and home (Table 2.1). Computers, cable and satellite television, movies on demand, and high-tech toys like video game systems have led to a decrease in physical activity in people of all ages. Reduced physical education requirements in schools across the nation have also caused physical activity to decline among adolescents. The CDC estimates that 70% of adults in the United States fail to meet minimal recommendations for physical activity. It also estimates that
about one-third of people over the age of 18 get no leisuretime physical activity at all.
Other environmental factors that have been linked to obesity are lower economic class, lower education level, and cessation (quitting) of smoking. The link between economic level, educational background, and obesity is not clear. One theory is that a person who is illiterate may not be able to read labels on food and may not be aware he or she is consuming high-fat, high-calorie foods that can lead to obesity.High-fat, high-calorie foods, such as the food served at most fast-food restaurants, are formulated to be cheap and great tasting. This food is readily available and affordable for people with lower incomes and it is speculated that these people may consume more of this type of food, which can lead to obesity.
People who quit smoking are also likely to gain weight and potentially become obese. It is believed that the nicotine withdrawal a person experiences when he or she quits smoking causes an increase in appetite that leads to an increased intake of calories and, thus, weight gain. This trade-off is not an easy one to handle. The harmful effects of smoking are many and include lung cancer, bronchitis (an infection of the tube that brings air to the lungs), and emphysema (a condition that results in labored breathing and increased risk of infections). Many people who quit smoking trade one health risk (smoking) for another (obesity) because they gain weight.

Genetics,Causes of Obesity

Genetics clearly play a role in obesity. It has been noted that an
adopted child’s body weight is usually more similar to the body
weight of his or her biological parents than that of his or her
adopted parents. Identical twins usually have similar occurrences
of obesity. Studies have also shown that fraternal twins
do not show this same likelihood of obesity; when one twin is
overweight, the other is very often not. These examples help
demonstrate that genetics play a significant role in obesity.
Researchers participating in the Human Obesity Gene
Map project are in the early stages of determining which genes
contribute to obesity in people. Several alterations in normal
genes have been discovered in laboratory rodents and linked to
obesity in these animals. These genes include the ob or lep gene
and the Agouti gene. Researchers are working to find out if
these same genes contribute to obesity in humans.
Not all people who have obesity genes will be overweight.
Conversely, some people who are overweight will not have
these genes. This is because environmental factors also play
a major role in causing overweight and obesity.

WHEN ARE DIET PILLS, ERECTION, HAIR GROW DRUG RECOMMENDED?

DIET PILSS NEED?
Overall, in carefully selected patients, a doctor may prescribe appropriate drugs to be used in conjunction with diet and exercise to achieve weight loss. The only drugs recommended for use by the National Heart, Lung, and Blood Institute (NHLBI) are those that have been approved by the U.S. Food and Drug Administration (FDA). FDA-approved drugs have been studied and determined to be safe and effective for some, but not all, people.
According to the NHLBI, people who are appropriate candidates and should consider taking diet pills are adults with a BMI of greater than 30 kg/m2 or those with a BMI of higher than 27 kg/m2 who have health problems related to being overweight. Diet pills, like any other medication, have risks associated with their use. Therefore, diet pills should only be used by people who are at high risk of developing weight-related health problems. For people who are obese or overweight, the benefits of weight loss are generally greater than the risks associated with taking slimming pills. Several slimming pills have been studied for use in children; however, doctors only recommend using them in extreme situations.
The National Institutes of Health (NIH) has established guidelines on the use of diet pills. These guidelines are used by health-care practitioners both within and outside the United States. The information contained in these guidelines helps to determine who should and should not use weight loss medications. This is important because people who use diet pills inappropriately risk potentially devastating effects on their health.
ERECTION DRUGS NEED?When a man is aroused, nerve signals are sent from the brain and around the penis. These nerve signals cause chemicals to be released that relax the muscles in the penis. Normally, these muscles are constricted so that blood cannot flow into the penis. When these muscles relax, large amounts of blood are able to enter the penis, causing an erection. An erection is reversed when another chemical (known as phosphodiesterase type 5 [PDE5]) breaks down the chemicals that caused the muscles to relax in the first place. This causes the muscles in the penis to constrict again as blood leaves the penis. Cialis works by blocking PDE5. When PDE5 is blocked, more of the chemicals responsible for the erection remain, so the muscles in the penis do not constrict. This allows blood to stay in the penis longer, which allows the man to maintain an erection.
HAIR GROW DRUGS NEED?With at least forty treatments for baldness patented in 1996 and $200 million budgeted for clinical trials in 1997, you'd think someone might have figured out by now why men lose hair. But the lab guys know only one big thing: Hair follicles shrink and die. They've proved that this tragedy is triggered by the body's especially potent testosterone derivative, DHT. But researchers can still only theorize about why the perfectly normal presence of DHT leaves some otherwise healthy men mourning their hair as it swirls down the drain.
Propecia, the next treatment to grind its way through the FDA-approval machinery, probably within the year, will be Merck's promising finasteride tablet, Propecia. Finasteride inhibits the enzyme that turns testosterone into DHT--the first domino in the chain reaction that ends in follicle death. It first appeared in the guise of Proscar, a drug that combats prostate enlargement, another problem caused by DHT. Merck's trial results have raised high hopes for Propecia's effectiveness: More than half of those treated had "clinically significant increases in growth of new hair." Some baldsters, wanting to get the jump on the approval process, are already cadging prescriptions for Proscar from their physicians.