Obesity is excess body weight. Body weight of a person is due to muscle, fat, bones, body tissues and water content. Obesity is excess fat in the body causing excessive weight. Obesity is an important medical problem not only due to its cosmetic concern but also a significant risk factor for serious illnesses like heart disease, increased blood pressure, stroke (neurological illness), diabetes, joint pain or even cancer.
WHO (world Health Organisation) definition of health: “Health is a complete physical, mental and social well being and not merely absence of disease or infirmity”. Considering WHO definition of health and the prevailing condition of overweight and obesity in general population, many individuals may not qualify the criteria of good health. Both developed and developing nations are affected with the problem of obesity. Moreover, the issue is prevalent both in children and adults.
Obesity is a complex disease of body fat. Obesity is diagnosed when the body mass index (BMI) is 30 or higher. BMI is calculated by dividing body weight in kilograms by height in meters squared (Kg/m2). BMI does not directly measure body fat but gives a reasonable idea of the same.
As per the WHO, the normal BMI should range between 18.5 kg/m2 to 24.9 kg/m2. The value higher than 24.9 kg/m2 indicates overweight. Further, the cut-off point of BMI for Asian Indian is 18·5–23·0 kg/m for Asian Indians due to ethnic differences and dietary habits. Studies have reported that India is the third country in the world with highest number of people with obesity and overweight with prevalence of 11% in adolescents and 20% in adults.
Childhood obesity has significantly increased and still rising across the globe. Two-thirds of pregnant women are obese/overweight, as are 20% of preschool children. Evidence suggest that maternal obesity, diabetes, and western-style diets create a long-lasting effects on multiple systems, including infant stem cells, the early immune system, and gut microbiota. Such exposures accelerate generation of fat tissues, disrupt body metabolism, and impair energy balance, affecting development of various organs in the body including brain.
The increasing use of Caesarion delivery without medical indication, an increased understanding of its health effects on women and children has become crucial. There is emerging evidence that babies born by Caesarion delivery have different hormonal, physical, bacterial, and medical exposures, and that these exposures can subtly alter neonatal physiology. There are several conditions that may be evident in early or late phase of childhood. There are frequent reports of greater incidence of late childhood obesity in such babies.
In a recent retrospective analyses, it was found that most of the adolescents with normal weight had always had a normal weight throughout childhood. Approximately half (53%) of the obese adolescents had been overweight or obese from 5 years of age onward. Further it was shown that almost 90% of the children who were obese at 3 years of age were overweight or obese in adolescence. Among the adolescents who were obese, the greatest acceleration in annual BMI increments had occurred between 2 and 6 years of age. Importantly, children who are overweight by the age of 5 are 4–5 times more likely to be obese as adolescents compared to their normal weight peers. Promoting weight loss in children who are already overweight is difficult, and excess weight in childhood often tracks to obesity as an adult.
One of the robust predictors of childhood obesity is excessive use of screen media. The studies have shown that each additional hour of TV viewing per day increased the likelihood of obesity by 13% among children. Screen use may increase sedentary time and displace physical activity. Screen use may also expose children to advertisements for energy dense foods, which can prompt for immediate eating. Repeated advertisement exposure may also have a longer-term effect on shaping dietary preferences towards calorically dense foods. The American Academy of Paediatrics recommends that preschool-aged children engage in no more than one hour of high-quality media per day, preschool-aged children in the US average 17.5 h per week engaged in screen media, nearly 2.5 times the recommended limit. The scenario in India may not be different or even more.
Screen use may also increase children’s obesity risk because of the negative impacts on night-time sleep. Short and poor quality sleep are strong predictors of unhealthy weight gain in children . Both screen use before bedtime and screen use in the bedroom relate to disrupted sleep among preschool-aged children.
Causes of Obesity:
Obesity usually results due to multiple factors as follows:
- Genetics: Genes may influence the amount of body fat a person store and its distribution. The interaction between the genes and environment plays an important role in the manifestation of obesity. Despite a high heritability (40-70%) of obesity, the search for genetic variants associated with obesity susceptibility has been a challenging task. In Indian several genes are found to be associated with the problem of obesity.
- Family life style: Obesity runs in families not only due to genetic inheritance alone but also sharing similar eating and activity habits.
- Inactivity or sedentary life style: Person with reduced physical activities burns lesser calories daily than a physically active person. People with joint pain may have lesser physical activities adding to further weight gain.
- Unhealthy diet and eating habits: High calories diet with inadequate fruits and vegetables contributes to weight gain. People fond of fast food laden with high calories beverages and oversized portions are more prone for obesity. Sugar, particularly as free sugars or sugar-sweetened beverages, significantly contributes to total energy intake, and, possibly, to increased body weight.
- Medical Illnesses: In few medical conditions, obesity can be found as an associated feature like hypothyroidism, arthritis, and other hormonal and rare genetic diseases.
- Drugs: There are several medications that can lead to weight gain over a period of time. Some of these medications include antidepressants, anti-seizure, antidiabetics, antipsychotics, steroids and few antihypertensives.
- Age: Obesity can occur more in people with increasing age due to hormonal changes and tendency for reduced physical activities.
- Pregnancy: Sometimes women find it difficult to lose their body weight after the baby is born. This could lead to obesity in women.
- Disruption of sleep: Excessive or lack of sleep both are detrimental for body weight. The alteration of sleep causes hormonal changes affecting appetite thus gain in body weight. Disruption of physiological day-night cycles could contribute to the increased incidence of obesity. According to the American National Sleep Federation, the percentage of the people who reported a sleep duration of six hours or less increased from 12 to 37 % over ten years. Insufficient sleep leads not only to an increase of the total calorie intake but changes the meal preference in favour of palatable foods and meals with high carbohydrate content.
- Social & economic issues: People with socio-economic status that restrict healthy eating habits and exercise are prone to gain body weight. Interesting people with social surroundings of obese and spending more time with them are more likely to become obese.
Obesity may lead to following complications:
- High blood pressure (Hypertension)
- Impaired lipid profile (Dyslipidaemia)
- Heart disease (angina, myocardial infarction & heart failure)
- Stroke (reduced blood flow or haemorrhage into the brain)
- Cancers like breast, intestine, gallbladder, prostate, uterus, ovaries, liver and pancreas.
- Breathing disorder including sleep apnoea (breathing repeatedly stops and starts during sleep).
- Gallbladder disease mainly gall stones.
- Infertility in females often associated with polycystic ovarian disorder (PCOD)
- Decreased sperm count and erectile dysfunction in males
- Fatty liver diseases leading to inflammation of liver
- Osteoarthritis mostly affecting the weight bearing joints like knee and hip
- Poor quality of life due to lack of participation in various activities. People may avoid public places. Further, obese people are prone to develop depression, disability, sexual problems, isolation and reduced productivity.
The strategies to prevent weight gain are the same as that of losing weight. These are as follows:
- Regular exercise. 150 to 300 minutes of physical activity every week prevent weight gain. This include brisk walking and swimming.
- Healthy eating plan: Low calories, nutritious food like fruits and vegetables. Limits sweets and alcohol. Take three regular meals with limited snacking.
- Regular monitoring of body weight at least once in a week.
All the above plans to prevent excess body weight are also applicable for the treatment of obesity. Further, the followings approaches may be considered in patients with significant obesity that impairs the quality of life or associated with other obesity related complications.
- Drugs: Drug therapy for obesity has concerns due to its limited usefulness in terms of efficacy, non-specificity and several toxic side effects. Several drugs that were marketed earlier were withdrawn due to serious cardiac side effects or risk of suicide. Currently few drugs are used for weight reduction as a part of treatment strategy. However, the use of any medication for weight loss should be only under regular medical supervision.
- Surgery (Bariatric Surgery) for weight loss. This is currently widely used treatment for weight reduction especially in cases of morbid obesity (BMI > 40 kg/m2). The patient undergoes surgery of the stomach for modification of its capacity to reduce the food intake. The surgery require a surgeon who is trained in this procedure. There are scientific evidence that patients with diabetes with BMI > 35kg/m2 who underwent bariatric surgery have shown favourable clinical outcome for cardio-vascular complications. The patient with obesity and prediabetes have also shown benefits for weight reduction and reduction of diabetes. The follow up after surgery is critical for the success of the final clinical outcome.
- Newer drugs under development. There are several newer drugs in pipeline for weight reduction including targeted nano-therapy.
- Deep Brain Stimulation in refractory cases of obesity. Deep brain stimulation in hypothalamus have shown increase in resting metabolic rate thus could be a potential treatment of refractory cases in future.
It can be affirmed that psychological well-being and food control are two relevant factors involved in the success of weight-loss therapy in treating obesity. The uses of various technologies in gyms and interventions with smart phones have shown a positive effect on attaining the desired body weight. The simple rule of 10000 steps daily and not sitting for more than 30 minutes in a stretch can definitely help people in their weight control strategy.