Obesity is a condition of being overweight due to deposition of excess fat in the body which has a negative impact on the health of an individual. It is actually the result of an imbalance between the consumption of calories, often in excess of actual need of the body and their expenditure; the extra calories get deposited in the form of body fat.
Consumption of calories depends upon hunger and its regulation. Hunger is the sensation that forces a person to eat. It is caused due to contractions of stomach (part of digestive system). During hunger one may feel weak and irritable. Person can feel headache also. Satiety is absence of desire for food. It comes at the peak of satisfaction after taking food. Hunger and satiety both are regulated by hypothalamus in brain. Sensory influences, hormones, blood glucose level and storage of fat contribute in regulation of hunger and satiety through hypothalamus
The excess deposition of fat is mostly seen as increase in weight, alteration of body contours like appearance of paunch (pot belly), hump over upper back, double chin etc. However, it is not the external appearance that is the only problem but the actual harm of obesity is internal. Obese individuals are at higher risk of blood pressure (hypertension), heart attacks and strokes, higher risk of early diabetes, liver disorders like fatty liver and gall bladder stones. The additional problems of excess weight leads to increase pressure on joints leading to early arthritis, increase pressure on lungs leading to decrease respiration during sleep known as sleep apnoea. Obesity overall increases the risk of mortality and hence is now considered a disease which needs to be treated as soon as detected.
The incidence of obesity is increasing world over, even in developing countries like India where on one hand there is extreme poverty. This increase in obesity can be attributed to poor dietary choices like increase in consumption of junk food, early exposure to processed foods, erratic intake of meals, excess availability and consumption of high calorie foods. Side by side the physical activity is on the decline. This has been due to use of machines at home and office, availability of mechanised transport, increase use of computers or television for entertainment and now even playing virtual games. There are some more factors that can lead to obesity like a genetic predisposition, presence of obesity genes; diseases like hypothyroidism, diabetes, Cushing’s syndrome; eating disorders and psychiatric illnesses.
Measurement of nutritional status of an individual has traditionally been done by measuring the weight and height of an individual and comparing it to the standard weight and height charts made according to with regards to age, sex and ethnic origin. The recommended method used these days is calculation of the body mass index of an individual also termed as BMI. It is calculated as weight in kilograms divided by square of his height in meters.
For example the BMI of an individual with weight 65 Kg and height 1.65 mts. is 65÷(1.65)2 which is =23.8Kg/m2 according to the WHO (world health organisation) normal BMI is 18.5 to 24.9Kg/m2, person is overweight if BMI is 25 to 30 Kg/m2and obese is when BMI is above 30 Kg/m2. Other approved methods to quantify obesity are measurement of skin fold thickness at different sites of body, underwater weighing, CT scan and MRI.
The mainstay of treatment of obesity is controlled diet and a regular physical exercise regime. Treatment includes counselling for constant motivation, building of self esteem and behavior modification. An appropriate low calorie diet chart should be planned for weeks followed by months with help of dieticians. Exercise can be either joining gym classes, aerobics combined with yoga and brisk walking or jogging or swimming. In extreme cases after appropriate case study by specialist drugs may be given for few months. Surgery for treatment of severe obesity or untreatable obesity is also gaining popularity. It is known as bariatric surgery.
References:
- Jeffrey S.Flier, Eleftheria Maratos-Flier (2005); Obesity, Harison’s principles of internal medicine 16th edition, Mcgraw Hill companies, USA, vol 1, 422-429.
- Crowley Ve et al (2002); Obesity therapy; Altering the energy intake and expenditure balance sheet, Nat Rev drug disc 1: 276.
- img credit: http://healthland.time.com/2012/01/17/u-s-obesity-rates-remain-stubbornly-high/