Obesity is the presence of excessive adipose tissue (fat) mass affecting the health status of any individual to an extent that it may lead to the risk of other serious health conditions. It is one of the most common global health problem replacing the more traditional public health issues.
Obesity in adults vs children
In order to classify an adult as obese, the body mass index (BMI) can be calculated that best classifies an individual according to his height and weight.
BMI: It is the weight of the individuals body divided by the square of the body height ( expressed as kg/m2). The standard classification of an individual is given in table 1.
Note-BMI is not the best indicator for health as your excessive weight can also be due to healthy bulging muscles rather than fat storage. It does not give information on the fat storage distribution in the body especially in the waist region and cannot be used as a predictor for lifestyle changes and benefits.
Obesity in children
In infants and children within 5 years of age, the obesity is determined according to the World Health Organization (WHO) “Child growth standards” and the WHO reference values for 5-19 years (body mass index-for-age).
WHO classification (birth to age 5)
- Obese: Body mass index (BMI) > 3 standard deviations* above the WHO growth standard median*.
- Overweight: BMI > 2 standard deviations* above the WHO growth standard median*.
WHO classification (ages 5 to 19)
- Obese: Body mass index (BMI) > 2 standard deviations* above the WHO growth standard median* (equivalent to BMI 30 kg/m2 at 19 years).
- Overweight: BMI > 1 standard deviation* above the WHO growth standard median* (equivalent to BMI 25 kg/m2 at 19 years).
*Growth Standard median: This is the standard of weight given for boys and girls by WHO according to the weight-for-length and weight-for-height of the children at a particular age.
*Standard Deviation: The weight difference of a child when compared to the mean (average) weight of the children belonging in the same age group.
Other classification for childhood obesity
- Child is overweight: if BMI at or above the 85th percentile* and lower than the 95th percentile for children of the same age and sex.
- Child is Obese: if BMI is at or above the 95th percentile* for children of the same age and sex.
*Percentile: It is a term used in statistics to give a value of a percentage of a child’s weight compared to the weights of the children of the same age group. For example, a test score that is greater than or equal to 75% of the scores of people who took the test is said to be at the 75th percentile rank.
Measuring Body fat in Adults
Waist Circumference: This method measures excessive fat around the waist and can be used as an additional measure in people who are obese or pre-obese according to the BMI.
For men, a waist circumference no more than 94cm and for women no more than 80cm is considered a safe range. Beyond which, one can develop obesity-related health problems.
Factors that lead to obesity
Genetic factors: The risk of obesity can be more if one or both parents are obese. This relationship of genes and obesity due to the environment and eating habits.
Age: With age, there can be a decrease in the metabolism of the body and loss of muscle mass. If physical inactivity ensues, coupled with bad eating habits, this can easily increase their ability to store fat in the body. Sometimes hormonal changescan also play a role leading to obesity.
Gender differences: Women tend to gain weight during pregnancy due to hormonal changes. Hormonal changes including estrogen, progesterone hormones can lead to weight gain. Imbalances in these hormones can also trigger insulin resistance, which in turn, leads to fat storage. In Men, imbalances in testosterone hormone can lead to weight gain. In general, it is observed that women are more at risk of weight gain compared to men also due to lifestyle differences.
- Physical activity: With improvements in modern technology and conveniences, there is an increasing lack of physical activity.
- Food habits: Consuming foods with excessive fat, sugar and calorific foods. Increased snacking and overeating can lead to excessive fat storage.
- Stress and lack of sleep: Both stress and lack of sleep can slow the body’s metabolism. Eating late at night can cause indigestion and leads to fat storage.
- Socio-Economic Status: Lack of resources, lack of access to healthy foods, unable to afford healthy foods or improper cooking habits, eating out too often can all lead to obesity.
- Side effects of medications: Certain pain medication, corticosteroids, antidepressants, thyroid medications taken by people with thyroid problems and other medicines can slow down metabolism and lead to fat storage.
- Known Medical Problem: Arthritis in the lower limb causing pain on weight bearing can reduce physical activity that leads to increasing fat storage.
Diseases such as stroke, kidney disease, Prader-Willi syndrome, Cushing’s syndrome and many others can prevent the person from engaging into physical activities due to pain or muscle/joint problems etc.
Consequences of Obesity
The major metabolic risk factors resulting from obesity are
- An increase in the total cholesterol concentrations especially triacylglycerol concentrations, and high-density lipoprotein (HDL) concentrations.
- High blood pressure
- Diabetes: Insulin resistance and glucose intolerance.
All this may lead to Metabolic syndrome that describes a group of risk factors that can increase the risk of developing a heart condition.
Diabetes: Obesity can lead to deficiencies in sex-specific steroid hormones (estrogen, progestin etc) that causes insulin resistance and a decrease in glucose metabolism.
Coronary Heart Disease (CHD): Metabolic syndrome and diabetes can lead to atherosclerosis and blocking of the major arteries of the heart leading to a heart condition.
Osteoarthritis: Osteoarthritis (OA) is an inflammatory condition that can be caused by obesity. Excessive weight gain can lead to wear-and-tear of the cartilage and bone leading to inflammatory joints. Other reasons underlying the relationship between obesity and osteoarthritis can be metabolic changes associated with increased fat storage.
Pulmonary disease: Excessive weight gain in the upper body can increases breathlessness that will lead to CO2 retained in the body and a mismatch in the ventilation and blood flow that further worsens the respiratory system.
Hypertension: The exact cause is unknown, however, due to weight gain there is an increase in resistance to blood flow to and from the extremities. Increases in body mass index (BMI) can put an individual at a higher risk of developing hypertension.
Gallbladder disease: Obesity is associated with increased secretion of cholesterol in the gallbladder that increases the risk of gallstones particularly cholesterol gallstones.
Hormonal disturbances: Increased obesity in women leads to increased male hormone (testosterone) production leading to hormonal imbalances. Upper body obesity is associated with an increase in testosterone that may be a major cause of problems related to menstruation. Obese men can also get hormonal problems that lead to erectile dysfunction. Childhood obesity can cause early puberty and hormonal problems later in adulthood.
Some forms of cancer: There is an increased risk of growth of cancer cells in various body tissue among obese people.
Fatty liver: Nonalcoholic fatty liver disease, a condition in which fat storage is excessive in the liver that can cause inflammation of the liver tissue and scarring(Cirrhosis).
Various psychological problems: There has been increased links of obesity with depression and mood problems possibly due to underlying hormonal problems or other conditions.
Prevention and Treatment
- Realistic healthy weight loss goal
Comprehensive lifestyle changes:
- Dietary changes: Avoid calorific or sugary foods. Developing meal plans to track what you consume. Seeking advice from a specialist to know what nutrients you are lacking or how to go about the changes.
- Increasing physical activity
- Exercise: 3-4 times per week for 30 minutes each.
- Group support: Joining a weight loss group can help psychologically and improve motivational level toward achieving your goals.
- Relaxation and stress management
Adherence to a weight loss program is important to bring about changes and to prevent health problems due to obesity. For further detailed assessment and treatment, it is best to consult an expert for individualized weight loss programs.