Obesity – Symptoms & Causes

Obesity Types: Causes, Treatment, Risk Factors

Obesity Overview

Obesity is a common condition characterized by excessive body mass. It is often a long-term or chronic health condition that progresses over time. Having excessive body fat may deteriorate health greatly and increase the risk of many health conditions, including high blood sugar and pressure, heart diseases, etc.

It is possible to improve health by getting rid of excess body fat. A slight reduction in weight can hugely impact your health.

What are the Types of Obesity?

Healthcare providers classify obesity into three categories based on body mass index. It measures average body weight against average body height. However, it is important to understand that this method has its own limitations. Nevertheless, it can indicate obesity-related ailments.

The three classes of obesity based on which healthcare providers may curate specific treatment plans for each individual include the following.

  • Class I: BMI 30 to <35 kg/m²
  • Class II: BMI 35 to <40 kg/m²
  • Class III: BMI 40+ kg/m²


BMI Class
18.5 or under Underweight
18.5 – < 25 “Normal” weight
25 – < 30 Overweight 
30 – < 35 Class I obesity
35 – < 40 Class II obesity
40 or over Class III obesity

Symptoms of Obesity

In general, there are no specific symptoms associated with obesity. A doctor or healthcare provider may diagnose obesity in an individual based on the following factors:

  • Having a body mass index over 30 kg/m²
  • Excessive amounts of abdominal fat that are higher than fatty deposits in other parts of the body
  • Having a waist circumference of greater than 40 inches for men or 35 inches for women

Causes & Risk Factors:

Although there are genetic, behavioural, metabolic and hormonal influences on body weight, obesity mostly occurs when you consume more calories than you burn through normal daily activities and exercise. Over time, these extra calories add up and cause weight gain. However, many individual factors must be considered to understand the cause of overweight in an individual. In some cases, preventing overweight requires working consciously against these multiple factors individually.

Risk factors that may increase calorie consumption and lead to obesity may include the following.

  • Fast and junk food: Consuming highly processed and junk foods leads to high-calorie intake. These foods are high in sugar, saturated fats, and even sodium but low in fibre and other essential nutrients. These ingredients build fat faster and promote an addictive eating habit leading to overweight.
  • Sugary foods: Foods and drinks laden with sugars have no nutritional value but add a lot of calories. Such foods also make it an addictive consuming habit.
  • Psychological factors: People dealing with boredom, loneliness, anxiety, and depression often resort to binge eating as certain types of foods trigger the pleasure centres in the brain. Often, such foods are high in calories and lead to obesity.
  • Hormones: Hormones regulate our hunger and satiety signals. Many factors can disrupt these regulatory processes, including common factors like stress and lack of sleep and less common factors like genetic variations. Hormonal fluctuations or imbalances can cause you to eat more than you need to, thereby causing easy fat deposition and obesity.
  • Certain medications: Certain types of medications like antidepressants, beta-blockers, diabetes medicines, and anti-seizure medications are known to cause weight gain as a side effect.

Other risk factors may also lead to obesity. These may include: 

  • Inactivity: Having an inactive lifestyle where you don’t exercise enough or at all can easily cause you to gain weight. One of the biggest factors associated with an inactive lifestyle is screen attachment. The number of hours spent in front of the screen is highly associated with weight gain.
  • Age: Although overweight can occur at any age, hormonal fluctuations occurring when growing older and a less active lifestyle can increase the risk of overweight. 
  • Pregnancy: Gaining weight during pregnancy is a common occurrence, but sometimes, women find it difficult to lose weight after having given birth. This weight gain may later on cause fatness among women.
  • Quitting smoking: It may sound strange, but when you quit smoking, one of the side effects is associated with obesity. People often try to cope with withdrawal syndromes after quitting smoking by replacing it with something else, which is often food. Binge eating or eating more than required leads to weight gain and, subsequently, fatness.
  • Lack of adequate sleep: Not getting enough sleep or even sleeping more than necessary can cause hormonal changes that increase appetite. This may cause cravings for foods high in calories and carbohydrates, which can contribute to weight gain.
  • Stress: People coping with stress may often seek comfort in consuming foods which are high in calories. This may lead to weight gain and obesity if not managed promptly.
  • Microbiome: The composition of your gut bacteria is affected by what you eat and may contribute to weight gain or even cause problems in losing weight.

Having one or more of these risk factors doesn’t imply that you are bound to become obese. You can counteract most risk factors through a balanced diet and adequate physical activity and exercise. Behavioural changes, medicines, and certain procedures for overweight can also help.

Complications Associated with Obesity

People with obesity are likely to develop a number of potentially serious health problems, including the following:

  • Heart diseases and stroke: overweight makes an individual more susceptible to high blood pressure and unhealthy cholesterol levels, which are risk factors for heart disease and strokes.
  • Type 2 diabetes: Obesity can impact the way that the body utilises insulin to control blood sugar levels. This increases the risk of insulin resistance and diabetes.
  • Digestive problems: Obesity increases the likelihood of developing heartburn and other problems associated with the hepatopancreatobiliary system, such as gallbladder disease and liver problems.
  • Osteoarthritis: overweight increases the stress on the weight-bearing joints. This may lead to the wearing away of the joints along with inflammation, swelling, and pain, among other symptoms that may eventually lead to osteoarthritis. 
  • Sleep apnea: People with overweight are more at risk of sleep apnea, which is a severe disorder in which breathing pauses abruptly during sleep.
  • Fatty liver disease: Fatness increases the risk of fatty liver disease. It is a condition of the liver in which there is excessive fat deposit on the liver. This may lead to severe liver damage, known as liver cirrhosis.
  • Certain cancers: Being obese has been associated with an increased risk of cancer of the uterus, cervix, endometrium, ovary, breast, colon, rectum, oesophagus, liver, gallbladder, pancreas, kidney and prostate.


Obesity is a chronic health condition caused by excessive fat deposits, particularly around the waist and other parts of the body. It may increase the risk of developing various other health conditions, including heart diseases, diabetes, and even certain cancers. It is possible to prevent or improve obesity by making lifestyle modifications and medication. In some cases, surgical treatment may also help manage overweight in addition to making lifestyle changes.