It is well known that the obesity is an excess proportion of total body fat. Woman is considered obese when her weight is 20% or more above normal weight. Body Mass Index (BMI) is usually used for objective obesity measures. Women could be considered overweight if their BMI is between 25 and 29.9 and women could be considered obese if their BMI is over 30.
In general the obesity occurs when a person consumes more calories than they need for the energy they use. At the same time several factors could have the influence at weight gain.
Overeating and lack of physical activity are the main causes of overweight and obesity. Such factors like eating habits and environment play less important, but still large roles in obesity development.
Some scientists highlight the importance of genetic predisposition, metabolism specifics, some illnesses, aging, emotional, socioeconomic, cultural factors and some other factors in obesity development. Obesity management could be very complicated because of several causes and important factors.
OBESITY, Overeating and Negative Energy Balance
Several studies demonstrated that obese people usually eat 1.5 – 2 times more proteins, carbs and fats than it is necessary for normal function of their body. Moreover, obese people always tend to eat sweet, fatty and very caloric foods. Certainly, in order to satisfy their large body’s needs, obese people consume more foods and drinks that result in overeating and inability to burn the calories they received.
Generally speaking obesity means - the amounts of calories (energy) received with food and drinks are much higher than the amounts of the calories spent for body functions and physical activities. As a result – the energy disbalance occurs and permanent prevalence of calorie intake over calorie spending leads to weight gain and obesity.
OBESITY & Appetite
Appetite is determined by processes that occur both in the brain and gastrointestinal tract. It is important to mention that eating patterns are controlled by areas in the hypothalamus and pituitary glands.
In general body produces numbers of molecules that increase or decrease appetite, including hormone leptin. Leptin is produced by fat cells. Some scientists suggest that leptin could also be released by cells in the stomach. Leptin appears to play an important role in insulin resistance and fat storage in the body, but its role in obesity is unclear.
The most likely scenario is that leptin levels raise as the cells store more fat. This increase in leptin levels decreases appetite. Falling
levels of leptin make person feel hungry. In people who have genetically lower levels of leptin, however, the brain may be tricked into thinking that it is always starving because there is no leptin to decrease appetite. This can lead to weight gain.
OBESITY & Physical Inactivity
Lack of physical activities is very typical for modern life. Modern people spend a lot of time in front of computers and TV. At the same time modern people use cars for any activities starting from shopping and finishing with weekend picnics. At present time walking activities are dramatically decreased. That kind of lifestyle plays a major role in obesity and weight management, because modern people do not spent all received energy from foods and store it in the form of fat. Average norms of our physiological needs make us spend about 600 Kcal a day, but we hardly spend 200-300 Kcal. The specialists argue that those people, who spend 2 hours a day watching TV have a strong tendency to become obese. In addition to that, obese people usually try to limit their physical activities - that leads to gaining extra weight and more limits to physical activities. This way they fall into a vicious circle: inactivity leads to increased weight gain, and weight gain leads to increased inactivity. That is why it usually takes a lot of efforts to break this circle.
OBESITY & Physical activity
Active individuals require more calories than less active ones to maintain their weight. Additionally, physical activity tends to decrease appetite in obese individuals while increasing the body's ability to preferentially metabolize fat as an energy source. Much of the increase in obesity in the last 20 years is thought to have resulted from the decreased level of daily physical activity.
OBESITY & Bad Eating Habits
Our weight depends on what we eat and how we eat. People are not only eating more food than they did 20 years ago but also replacing home cooking with packaged foods, fast food, and dining out. This behavior put people at higher risk for obesity. Modern busy people have no time for having normal meals at work, so they try to compensate this with overeating in the evening. Having snacks and eating on feet does not bring to anything good as well. Modern fast food industry is a known killer of our health, not only because of the abundance of harmful fats and acids in those hamburgers and French fries, but also because of oversized portions and fast eating. At the same time there is a great deal of spicy, fatty, over-salted and over-cooked foods available everywhere. Consuming a lot of coffee, energy drinks and/or alcohol also leads to weight gains.
Frequent small, healthy meals (instead of two or three large daily meals) have been associated with lower weights.
OBESITY & Age
Age is an important factor in obesity causes. As you get older, your body's ability to metabolize food slows down and you do not require as many calories to maintain your weight. This is why people note that they eat the same and do the same activities as they did when they were 20 years old, but after 40-50 gain weight.
OBESITY & Gender
Women tend to be more overweight than men. Men have a higher resting metabolic rate (men burn more energy at rest) than women, so men require more calories to maintain their body weight. Additionally, when women become postmenopausal, their metabolic rate decreases. That is partly why many women gain weight after menopause.
OBESITY & Genetics
In many cases, overweight and obesity run in families, and the specialists say that over 50% of obese people are under effect of genetic predisposition to being overweight. Genes can affect the amounts of fat your body stores. However, it was proven that the genetic factor can get activated only when it is accompanied with other factors, such as bad eating habits and physical inactivity.
If your biological mother is heavy as an adult, there is approximately a 75% chance that you will be heavy. If your biological mother is thin, there is also a 75% chance that you will be thin. Nevertheless, people who feel that their genes have doomed them to a lifetime of obesity should take care of used calories. Many people genetically predisposed to obesity do not become obese or are able to lose weight and keep it off.
Genetic factors could play some part in 70 - 80% of obesity cases.
OBESITY & Environmental factors
Although genes are an important factor in many cases of obesity, a person's environment also plays a significant role. Environmental factors include lifestyle behaviors such as what a person eats and how active he or she is.
Environmental factors include excessive amounts of fast food, alcohol and energy drinks advertisements, poor quality products in super-markets and lack of access to healthy foods, our working schedules, lack of sidewalks, playgrounds, recreation facilities in modern cosmopolitan cities, and so on. Undoubtedly all mentioned factors lead to promoted unhealthy lifestyle, not healthy food, laziness and poor weight management.
OBESITY, Emotional & Psychological factors
Emotional factors of obesity are sometimes underestimated as the important causes of weight gain. When we are stressed out, worried, angry or depressed, we frequently tend to compensate our nervous tension with eating nuts, pop-corns, sunflower seeds and other quite caloric foods. During emotional stress women usually consume more calories and spent much less (reduced physical activities). All these is resulting in storing fat and extra calories and gaining weight.
Sometimes society creates more stresses for obese people. Many people wrongly stereotype obese people as gluttonous, lazy, or both. However, more and more evidence contradicts this assumption. Obese people often face prejudice or discrimination at work, at school, while looking for a job, and in social situations. Feelings of rejection, shame, or depression are common.
Psychological factors also influence eating habits and obesity. Many people eat in response to negative emotions such as boredom, sadness, or anger. People who have difficulty with weight management may be facing more emotional and psychological issues; about 30% of people who seek treatment for serious weight problems have difficulties with binge eating. During a binge-eating episode, people eat large amounts of food while feeling they can't control how much they are eating.
OBESITY & Illnesses
Some illnesses can cause obesity including the following:
- Hypothyroidism (poorly acting thyroid slows metabolism). Patients with an underactive thyroid generally show only a moderate weight increase of five to 10 pounds.
- Very rare genetic disorders, including Froehlich syndrome in boys, Laurence-Moon-Biedl syndrome, and Prader-Willi syndrome, cause obesity.
- Abnormalities or injury to the hypothalamus gland can cause obesity.
- Cushing's disease is a rare condition caused by high levels of steroid hormones. It results in obesity, a moon-shaped face, and muscle wasting.
- Obesity is also linked to polycystic ovarian syndrome, a hormonal disorder in women.
- Some rare diseases of the brain that can lead to overeating.
In such situation, it is crucial to treat the health condition first, and then start combating the problem of overweight.
OBESITY & Medication
Certain drugs, such as steroids, some antidepressants, female hormones (birth control pills, progestines), insulin and insulin stimulating drugs could cause excessive weight gain by affecting the routine processes of calorie burning in the body and by increasing the appetite. It could lead to weight gain.
OBESITY and some other Factors
It is possible to name some other factors which cause obesity. Aging leads to less physical activity, causing weight gaining. Pregnancy is another cause of weight changes in women. Finally, the people who have constant lack of sleep, or are trying to quit smoking are also reported to have a tendency to eating more and gaining weight.