OBESITY
What is Obesity?
The World Health Organization defines Overweight obesity as a chronic complex disease caused by abnormal or excessive fat accumulation that is a risk to health. It is in most cases a multifactorial disease due to environmental factors, psycho-social factors, and genetic causes. A body mass index (BMI) over 25 is considered overweight while BMI over 27.5 kg/m2 is defined as obese.
- What are the health risks of obesity?
Numerous diseases are associated with obesity some of which are listed below (but not limited to):
- Adult Type 2 diabetes
- Ischemic heart disease
- Hypertension (↑ BP)
- Obstructive sleep apnoea (persistent snoring)
- Osteoarthritis (chronic knee pain)
- Non-alcoholic steatohepatitis (NASH), NAFLD
- GERD (heart burns, acidity)
- Dyslipidaemia
- Social embarrassment
- Depression
- Infertility
- Polycystic Ovarian Disease
- Stress incontinence
- Lower limb venous stasis
- Intertrigo
- Lymphedema
- Cancers
- What are the causes of obesity?
There is calorie accumulation which is converted and stored as fat. If one burns or utilizes the calories that one consumes regularly, then their weight would be constant. If one is not able to do the same and consumes calories in excess, then even a few 100 Kcal extra consumed every day would result in a significant weight gain over the years! It is about lifestyle. Someone would say ‘Everyone in my family is overweight’ and this would be true since they may have similar dietary habits and lifestyle. One important cause of weight gain is a sedentary daily routine which is due to a lifestyle of convenience. When we work a lot I ‘exhaust’ not ‘exercise’. The abundance of high-calorie, cheap ready-to-eat food (fast foods) in today’s world is one significant factor. SEVERE OBESITY: The causes of morbid obesity are multiple and complex. Research has indicated that the underlying cause of morbid obesity may be genetic hence we cannot blame someone for his/her obesity as they may be doing everything right and trying their best to lose weight but still are unable to do so. - How to know if one is obese?
There are many ways to quantify obesity. Body Mass Index (BMI), fat %, waist circumference, and waist-hip ratio are some of them. BMI is the most popularly used unit to measure obesity but unfortunately, it is flawed as it does not consider the activity levels, body fat mass, and other body composition differentials. It is calculated by the formula Wt (Kg)/Height (mt2)
ft
in
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BMI
Classification of obesity | ||
BMI (Global) | Classification | BMI (Asians) |
25 – 29.9 | Overweight | 23 – 24.9 |
30 – 39.9 | Obese | 25 – 32.4 |
> 40 | Morbid obesity | > 37.5 |
> 35 – 39.9 + Co-morbidities | Morbid Obesity | 32.5 – 37.4 + Co-morbidities |
- Is waist circumference important?
The significance of increasing weight or waist circumference is that it is directly proportional to the risk of developing diabetes, hypertension, ischemic heart disease, and cerebrovascular accidents. The waist circumference also indicates the volume of central obesity or visceral fat, which is largely responsible for metabolic diseases like insulin resistance and fatty liver disease. The normal upper limits of waist circumference as per WHO are given below:
Waist circumference limits (cm/inches) | ||
Global population | Gender | Asians population |
102/40 | Males | 90/35.5 |
88/35 | Females | 80/31.5 |
- How does Body fat percentage matter?
Body fat percentage is also an important measure of degree of obesity, especially for the Asian population who, even when thinner have a much higher body fat percentage leading to a higher risk of metabolic diseases. Women tend to have higher body fat percentages than men due to the demands of childbirth and other hormonal factors. The normal body fat percentage according to the American Journal of Clinical Nutrition is given below:
Age | Body Fat Percentage for Men | Body Fat Percentage for Women |
20-39 | 8%-19% | 21%-32% |
40-59 | 11%-21% | 23%-33% |
60-79 | 13%-24% | 24%-35% |
- How to reduce body fat?
Reducing body fat needs a controlled diet and exercise planning. Firstly, there must be a reduced daily calorie intake which is BMR adjusted. While the diet is reduced in calories from carbohydrates and fats, it must contain sufficient proteins, vitamins, and minerals. Secondly, this has to be coupled with enough exercise to increase the BMR, prevent loss of muscle, and aid fat loss. It is important to realize that fat loss will be generalized from all over and not selectively from certain areas of the body. - How successful is diet and exercise in reducing weight?
Diet and exercise work for weight loss. But when it comes to treating obesity over the long term it may have limited ability to do so since obesity is a chronic multifactorial problem. The diet plan must be calculated based on the BMR and the routine physical activity. Typically, when on a diet and exercise regimen one loses about 5 – 10% of the body weight for a few months and then regains the original weight or may even go beyond the original highest weight. This is called a ‘yo-yo’ effect, which may be detrimental if you have diabetes, hypertension, or other metabolic diseases. Reduced reduced-calorie diet keeps you hungry throughout the day, and adding exercise will require further determination to tackle the hunger. Unfortunately, this also leads to a reduction in the BMR as the body considers it as starvation. All this leads to a plateauing of the weight at a certain point since one cannot keep reducing the calories forever.