Obesity occurs when you calorie intake is more than calorie expenditure through your daily activities. These extra calories are stored as body fat. Obesity usually results from a combination of causes and contributing factors, including:

• Genetics: Genes are responsnible for the amount of body fat you store, pattern of fat distribution and efficieny of your metabolism. But even then environmental factors add on to genetics to make you obese.

• Family lifestyle: Family members tend to have similar eating, lifestyle and activity habits, thus the increased risk.

• Inactivity: Sedantary lifestyle doesn't burn as many calories and you can easily take in more calories than you burn off.

• Unhealthy diet and eating habits: A diet full of fast food, missing breakfast, and laden with high-calorie beverages and oversized portions contributes to weight gain.

• Certain medications: Medications including some antidepressants, anti- seizure medications, diabetes medications, antipsychotic medications, steroids and beta blockers may contribute to your weight gain.

• Age: Hormonal changes and a less active lifestyle increase your risk of obesity in the old age.

• Social and economic issues: Not having safe areas to exercise, knowing healthy ways of cooking or not having money to buy healthier foods may also predispose to obesity.

• Medical problems: Medical disorders such as Cushing's syndrome and arthritis (which decrease mobility) may result in weight gain.

Even with more than one risk factors, you can counteract them through diet, physical activity and exercise, and behavior changes.

Heath Hazards associated with obesity are:

• High triglycerides and low high-density lipoprotein (HDL) cholesterol

• Type 2 diabetes

• High blood pressure

• Metabolic syndrome — a combination of high blood sugar, high blood pressure, high triglycerides and low HDL cholesterol

• Heart disease

• Stroke

• Cancer, including cancer of the uterus, cervix, endometrium, ovaries, breast, colon, rectum, esophagus, liver, gallbladder, pancreas, kidney and prostate

• Breathing disorders, including sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts

• Gallbladder disease

• Gynecologic problems, such as infertility and irregular periods

• Erectile dysfunction and sexual health issues

• Kidney disease

• Nonalcoholic fatty liver disease, a condition in which fat builds up in the liver and can cause inflammation or scarring

• Osteoarthritis

• Poor wound healing

When you're obese, your overall quality of life may be lower, too. You may avoid public places, face discrimination, depression, Disability, Sexual issues, Shame and guilt, Social isolation and lower work achievement.

Obesity is a rising health problem especially among urban children. According to the World Health Organization (WHO), there were about 1.6 billion overweight adults aged 15 years and above and at least 400 million adults are obese worldwide in 2005. It is a serious public health problem that is growing in countries with low or middle income. According to IOTF (International Obesity Task Force), estimated prevalence rate of obesity could reach 45% to 50% in the USA, 30% to 40% in Australia, England and Mauritius and more than 20% in Brazil by 2025. Developing countries like India, face the double burden of obesity and under nutrition. The worldwide prevalence of childhood overweight and obesity increased from 4.2% in 1990 to 6.7% in 2010 and is expected to reach 9.1% or 60 million, in 2020. A study done at AIIMS (Delhi) has shown such prevalence to be around 20 percent among school going children of Delhi.

There are various endocrinological disorders which can lead to obesity. Usually these disorders are associated with compromised height, so if a child is not growing in height but has excessive weight, their parent should consult endocrinologist as early as possible to avoid the child losing on his adult height. There are some familial disorders associated with obesity and early recognition of these diseases may prove helpful for future generations

Obesity, never is a lone issue. Rather, it leads to further health related problems like hypertension, increased predisposition to diabetes, heart diseases and breathing difficulties and poor scholastic performance

Most people are surprised to learn that there is an association between obesity and infertility. Nearly one-third of the women who struggle to get pregnant are also obese. Fortunately, they can gain fertility back by simply restoring body weight to within normal limits.

• How does Obesity interfere with Fertility?
  Obesity leads to anovulation, menstrual irregularities and a reduced conception rate. In addition, obese women undergoing fertility treatments have a reduced response to such treatment, requiring much higher doses of gonadotropins and leading to lower chances of success with IVF or ICSI. Obesity also increases risk of miscarriage and exposes both the mother and the baby to risks before and after birth.

• How to treat obesity-related infertility?
  Even a moderate weightloss of only 5% of body weight can significantly improve the chances of conception by restoring regular menstruation and ovulation. However, the challenge of weight loss is daunting, as most obese people have tried diets, exercise programs and other methods to lose weight, but have not been successful.

• Why do weight-loss programs tend to fail?
  Weight-loss programs, especially in women with PCOS (which accounts for 95% of obese infertile women), are associated with high dropout rates of up to 38%. These disappointing rates are influenced by the hormone disruptions that characterize PCOS. Women with PCOS tend to gain weight rapidly because of insulin resistance, which has an anabolic effect, combined with an increased appetite and a tendency to crave high glycaemic index (GI) starches (sweets, white bread, cakes, etc) caused by the androgens their bodies are producing. In addition, psychological factors play an important role. Obese women with PCOS tend to feed their depressed moods with high-fat, high-GI foods, thus making the situation even worse. Also, such patients tend not to feel satiated because their ghrelin levels are also disturbed.

• What should a lifestyle intervention program consist of?
  In order to be successful, a program should include the triad of balanced and planned Nutrition, monitored physical activity, behaviour modifications to address negative self image and medications to decrease insulin resistance and to induce ovulation.
  Obese women need counseling, encouragement and understanding with praise for accomplishments for weight reduction. It is realistic to anticipate weight loss at the rate of half to one kg per week. Unrealistic expectations lead to abandonment of the weight loss program. Thus, treatment of obesity itself should be the initial aim in obese infertile women. More than 70% of women will conceive spontaneously if their weight disorder is corrected. A change of lifestyle, diet and exercise remains the simplest and the most effective solution to infertility associated with obesity.

Apart from the various disorders like diabetes, hypertension etc., that are its secondary consequences, obesity leads to a gamut of breathing difficulty ranging from Obesity Hypoventilation syndrome to Obstructive Sleep Apnoea Syndrome (OSAS). During the lying down position especially during sleep, the upper respiratory tract muscles’ tone is decreased, due to which there is partial or complete obstruction of the breathing pathway. In obese people, who usually have thicker neck and snore, pharyngeal muscle tone is lesser than that of a thin person, compromising the narrow breathing pathway in the neck thus leading to intermittent obstruction in the pathway of breathing. This is called Apnoea, the transient cessation of breathing. Apnoeas and hypopneas (Partial obsctruction) are more pronounced in the supine position during REM (dream) sleep and result in recurrent nighttime awakenings and increased respiratory effort. Furthermore, oxygen saturation often falls during, resulting in sympathetic system activation to restore the same. As and when the airflow and oxygenation return to normal, sleep usually continues. Recurrent arousals and sympathetic stimulation are associated with poor quality sleep as the cycles of obstruction, followed by restoration of airflow at the termination of events, continues throughout the night, sometimes repeating a number of times per hour. The measured episodes of apneas, plus hypopneas, per hour, is used to quantify the severity of disease as the apnoea- hypopnea index (AHI). OSAS, even in those patients where the etiology is other than obesity, may cause hypertension, systemic inflammation, and insulin resistance thus creating a cycle of the co-morbidities leading to one another. In this scenario, simply by losing weight and bringing their body weight to the ideal would improve the respiratory tract obstruction and distressed breathing and better the quality of life in these patients.