Obesity time to sit up and take
Tuesday December 5 2006 18:35 IST
Dr Mohan K Rao
Obesity is a condition characterised by excess body fat. The American College of Endocrinology viewed obesity as ‘‘disease state that warrants recognition’’ by health-care providers. Obesity can predispose to hypertension (high BP), Type 2 diabetes, hyper lipidemia (high cholesterol) and eventually cardio-vascular disease. Traditionally, obesity was believed to be associated with affluent life style in the west. However, obesity is a fast growing problem in developing countries. Several studies in India have shown that changes in dietary pattern, physical activity levels, lifestyles associated with affluence, and migration to urban areas are related to increased frequencies of obesity and the risk of diseases, such as coronary heart disease and diabetes.
As per study undertaken by Nutrition Foundation of India (NFI), 32.3 per cent of middle class men, and 50 per cent of women are obese. The prevalence of abdominal obesity was higher than the prevalence of overweight / obesity. Definition: Obesity is defined by calculating BMI (Body Mass Index), which is nothing but: weight in kgs / height (meters) * 2 As per WHO, (World Health Organisation), BMI is categorised as 18-25 - Normal 25-30 - Over weight 30-35 - Grade I obesity 35-40 - Grade II obesity greater than 40 - Morbid obesity Abdominal obesity is defined by calculating waist / hip ratio. A ratio greater than 1 in men and greater than 0.8 in women is considered abnormal. People with abdominal obesity are more prone to develop heart disease and diabetes. Factors responsible The factors responsible for this increased prevalence in obesity among the Indian population could include the following: 1. Increased genetic predisposition to syndrome X (syndrome consisting of hypertensions, insulin resistance, dyslipidemia and abdominal obesity). 2. Increase urbanisation leading to a. Consumption of a high fat diet.
b. An eat - on the run lifestyle.
c. Decreased physical activity. Mechanism of obesity: The causes of obesity are thought to be multifactor, including the genetics and environmental. Studies have shown that 40-70 percent of the variation in obesity related phenotypes, such as body mass index is heritable. The genetic causes of obesity could be due to the ones caused by many minor genes and others by a single major gene.
Common obesity afflicts majority of population in this industrialised world, probably is caused by few minor genes.
Energy balance cycle: The energy cycle is the pathway that connects a part of brain (hypothalamus) to the peripheral fact cells (adipocytes) through hormonal and neuronal signals. With this mechanism our body maintains the amount of food eaten and energy spent, thus maintaining our weight.
The pathway that send messages to the brain are:
Leptin: Leptin is a hormone secreted from the fat cell, which acts on region in the brain (hypothalamus), to decrease appetite, people with leptin deficiency tends to become obese very early in life. Ghrelin: Ghrelin is a hormone secreted from the stomach, released when stomach is empty, makes the person hungry. In contrast CCK (Cholecustokinin) a hormone released from the pancreas sup presses appetite. Central processing unit: Brain is the center where hormonal and neuronal signals interact to control energy balance and weight. Hypothalamus is a special center, containing feeding center and satiety center. From the brain information is carried through neuronal/hormonal signal to fat cells and increases/decreases energy spent.
Hence, obesity is a positive energy balance state where energy consumed is more than energy spent. Complications of obesity: Obesity leads to many complications:
1.Hypertension 2. Diabetes 3. Dislepidemia 4. Gall stones 5. Arthritis 6. Coronary heart disease 7. Certain type of cancers 8. Infertility 9. Low self esteem 10. Snoring, sleep apnea etc. Treatment Management of obesity is a complex process involving multi-speciality approach, including a. Endocrinologist.
b. Nutritionist c. Physiotherapist d. Clinical psychologist and e. A surgeon where required.
Diet and exercise are very important in the management of obesity. When diet and exercise fails obesity specialist will prescribe tablets. Currently there are 2 FDA approved drugs for the management of obesity. a. Subutramine - a drug which acts in the brain to reduce appetite b. Orlistat - a drug which inhibits the enzyme lipase in the intestine, reducing the amount of fat absorbed.
Both have to be prescribed by a doctor, and they cause significant weight reduction.
In case of morbid obesity (BMI greater than 40) or, obesity associated with complications, surgery can be done. Laparoscopic (key hole) gastric banding surgery is a special type of surgery, (more than 1,50,000 surgery are already performed in USA alone) also result in significant weight reduction. Conclusion: Obesity is a complex disease with genetics and environmental being the main factors, if untreated leads to many complications. When treated effectively in the early stages can significantly reduce complications of obesity.
Obesity in India