The common acronym of Body Mass Index is BMI, which is basically a number that is determined from one's body weight and height that more or less shows a relationship to the percentage of his/ her total body weight that comes from their body fat and not their muscles, organ or bone. As the BMI is directly related to the fat content in one's body, the higher BMI means a higher percentage of body fat. For instance, if the BMI of a person is below 20, it means that he/ she may possibly be underweight. When the BMI ranges between 20 and 25, it means that the person's weight is good considering his/ her height. On the other hand, when the BMI is more than 25, it denotes that the person is overweight, while BMI in excess of 35 means that the person is obese.
The good thing is that majority of the health as well as diet sites offer free charts and calculators to evaluate your Body Mass Index. However, the calculations you do using these charts and calculators are basically rough translations of the actual percentages. In addition, several other factors may also have an effect on your true BMI. In fact, these factors may have an impact on the total fat content of your body.
For example, our muscle is more compact compared to fat and, hence, it takes lesser space. Hence, it is possible that a person who has lots of muscles may weight more than another overweight person of the same size. In other words, two people having the same BMI may also have extensively different proportion of body fat. In such an instance, you may need more sophisticated equipment, for instance, an immersion tank, for calculating the precise body fat percentage. Compared to our muscle, body fat is more buoyancy and this is the reason why the buoyancy levels of two individuals with the same body weight will not be the same, especially when their body fat percentages are different.
Generally, compared to men, women have more subcutaneous fat, especially in their hips and breast. Therefore, it is very much likely that their body fat percentage will be higher even without this being reflected in their Body Mass Index or creating any unfavourable impact on their health.
Often when the body fat of an individual is very low, it may or may not reflect in a BMI. However, this largely depends on the person's muscle structure and/ or his/ her health conditions. In fact, it is essential for our body to store some amount of fat to obtain the energy required for the various bodily functions. In the absence of adequate body fat, our body will start consuming the muscle mass in order to keep its functions normal and after a while this may lead to severe ailments and health disorders. For instance, athletes who undergo excessive training may often find losing their strength, instead of gaining strength and vitality.
Body Mass Index, including all its rough calculations, is an excellent means to determine if you require losing weight, gaining weight or pat on your back for having the appropriate weight.
Apart from the Body Mass Index, people whose waist size is in excess of 40 inches (in the case of men) and 35 inches (in the case of women) actually have more chances of developing health problems related to obesity, for instance, high blood pressure (hypertension), heart diseases and diabetes.
There are various reasons for people becoming obese and some of them are discussed below briefly.
These days many people eat more than what they were earlier habituated to. Initially, this trend was rampant in developed countries, but now it has become a worldwide phenomenon, giving rise to obesity and related problems.
These days most people, especially those in developed and developing nations, are leading a more sedentary lifestyle, thanks to the advent of various gadgets and appliances like television, washing machines, computers, remote controls, dish washers and several other modern devices. On the contrary, their parents as well as grandparents were more active and healthy. Even a few decades back, when people went for shopping, they walked quite a distance down the road to the main street where their grocers, banks, bakers etc. were located. However, with the arrivals of large shopping malls and supermarkets out-of-town, people changed their habits. Instead of moving on their feet, they started driving to these places located at some distance to get their necessary items. In fact, in some developed nations, such as the United States, people's dependence on their car has been growing increasingly and they cannot do without their vehicle even when they have to travel half-a-mile!
However, the fact remains that the less you move around or the less active you are, the smaller number of calories you will burn. In turn, you build up more body fat, resulting in obesity and related health disorders. But the question is not only about calories and how you burn them. Even the physical activities you undertake regularly have an influence on the manner in which your hormones work. In turn, the hormones have an influence on how your body tackles with the ingested foods. Findings of many scientific studies have demonstrated that physical activity is also beneficial for the insulin levels in our body, as the more physical activity we undertake, the more stable are our insulin levels. When the insulin levels are unstable, it often results to unwanted weight gain - both are associated closely. It has been found that children having a television set in their bedroom are more prone to be overweight or obese compared to those who lack it.
Lack of sufficient sleep often increases the chances of a person becoming obese by two fold. Sleep is also necessary for sustaining our overall health and wellness.
The National Institutes of Health (NIH) say that all individuals who quit smoking do not necessarily gain weight. However, a large number of people become overweight or obese when they give up smoking and they typically add anything between 6 pounds and 8 pounds to their body weight. About 10 percent of individuals who give up smoking may gain a significant amount of body weight - about 30 pounds or even more. This is mainly because the appetite increases when people stop smoking. Smoking actually suppresses appetite.
It is worth mentioning here that genetic elements are basically forces inside an individual that facilitate him/ her to gain weight and remain overweight, while the environmental elements are the external forces that add to these problems. They include everything present in our environment that possibly encourages us to eat more food and undertake too little work-outs. Experts are of the view that when these are considered together, the environmental factors are the reasons or motivations for considerable augmentation in chubbiness.
Actually, the environmental effects come into force quite early in one's life, sometimes even prior to your birth. Occasionally, scientists refer to these as in-utero exposures or "fetal programming". For instance, chances are more that women who smoke during their pregnancy will give birth to babies who will turn out to be overweight compared to the babies of mothers who did not smoke during pregnancy. This also holds true for infants born to women who suffered from diabetes. Scientists are of the view that such conditions may change the metabolism of a growing baby in one way or the other and the effects may be reflected in different ways later in the life of these babies.
Following their birth, ideally babies should be breast fed in excess of three months, as this reduces their chances of becoming obese when they are adolescents. On the other hand, babies who are given their mother's breast milk for less than three months have increased risks of becoming obese later.
It has been noticed that often the childhood habits of people remain throughout their lives. Children who drink sweetened sodas and consume processed foods having high calorie content generally develop a liking for such foods and keep consuming them even during their adolescence and adulthood, thereby encouraging an inclination to gain weight and become obese. Similarly, children who are very inactive and spend most of their time watching television and/ or playing video games rather than taking part in active games tend to lead a sedentary life later on.
Several aspects of contemporary live also encourage weight gain. Briefly speaking, the present-day "obesogenic" environment persuades us to consume more and more, but undertake very little or no exercise at all. In fact, there is increasing evidence that the general aspects of our lifestyle or the way we spend our routine life - for instance our stress levels, the amount of sleep we get and other different psychological factors - also possess the potential to influence our weight.
Among other things, the side effects of many prescription drugs may also include weight gain, as they may enhance appetite or retard the metabolic process. Such medications comprise different corticosteroids like hydrocortisone, which is used to treat a wide range of health conditions with a view to alleviate inflammation; specific anti-cancer drugs; anti-convulsant drugs like valproic acid (Depakote and other branded medications); estrogen and progesterone (used in the form of oral contraceptives); and prescription drugs like haloperidol (Haldol), olanzapine (Zyprexa), clozapine (Clozaril), lithium (Lithobid and Eskalith), which are prescribed for treating psychiatric problems.
It is an irony that often people may also gain weight as a side effect of using a number of medications that are used for treating conditions that occur due to obesity itself! Some such drugs include insulin and glyburide (brand name DiaBeta as well as others). These medications are widely used to treat diabetes, a disease widespread among people already suffering from weight disorders. In addition, many anti-depressant medications may also result in patients gaining weight. Some such antidepressants include tricyclic antidepressants like desipramine (brand name Norpramin and Pertofrane), imipramine (Tofranil); selective serotonin reuptake inhibitors (also called SSRIs) like citalopram (Celexa), paroxetine (Paxil), sertraline (Zoloft), escitalopram (Lexapro), fluoxetine (Prozac) and fluvoxamine (Luvox); and monoamine oxidase inhibitors (also known as MAOIs).
When SSRIs are used to cure depression, these medications may initially lead to weight loss, but after undergoing treatment for six months, a large number of patients experience remarkable weight gain from the use of these drugs. Then again, another medication that fuels serotonin (such as the SSRIs) and called sibutramine (brand name Meridia) suppresses the appetite and is often prescribed to encourage weight loss in the patients. In addition, Prozac, a SSRI drug, may also result in weight loss in some patients. Therefore, this drug is also effective for treating weight related problems. Nevertheless, scientists need to undertake further studies to unravel much more in this area - the association between use of serotonin (a natural chemical present in the brain and used by the brain to send signals to other body areas) and weight regulation, which is definitely a very complex issue.
Some ailments occur along with an anomaly or imbalance in your endocrine glands and these have the potential to have an adverse effect on your weight. Some such illnesses include polycystic ovarian syndrome, hypothyroidism (wherein the thyroid glands are under active) and particular abnormal tumours of the adrenal glands, pituitary gland and/ or the pancreas. Nevertheless, in most people, weight gain does not occur due to these ailments, as many of them are actually very rarely occurring diseases. Among the diseases mentioned above, hypothyroidism is most common, but even this condition is rarely the prime cause for the patients becoming obese or overweight. Even when such patients undergo treatment using thyroid hormone, which is necessary in some cases, they generally do not experience notable weight loss.
Sometimes, people also become obese owing to certain rare as well as complex health problems, which have their origin in genetic disorders. The Prader-Willi syndrome is one such health disorder that leads to obesity. Precisely speaking, this condition is a type of obesity related to faint mental retardation, which only occurs in approximately 1 out of every 25,000 people. Scientists have traced this condition to anomalies in a cluster of genes on chromosome 15. Individuals suffering from this genetic disorder are generally very short built and mainly the upper part of their body becomes obese. The Bardet-Biedl syndrome, which is very akin to the Prader-Willi syndrome, but a much rarer genetic disorder, is attributed to anomalies in various genes. In addition to these, there are many other exceptional genetic syndromes that are responsible for obesity. However, these disorders are only responsible for a minute fraction of the entire weight related problems.