29.AUG.2017 10 MIN READ | 10 MIN READ

We have been told one too many times that being overweight or obese is bad, but did you know the extent of damage obesity has on your health?

Obesity significantly increases your risk of diabetes and high blood pressure, and these conditions are also intimately intertwined with heart disease. For instance, an obese person’s risk of a heart attack is 3 times greater than that of a person who has a healthy weight.

Obesity vs overweight

Although we have been using these two words interchangeably, there is a subtle difference in their medical definitions.

Obesity is a condition where a person has accumulated so much body fat that it might have a negative impact on their health. This is different from being overweight, where the weight may come from muscle, bone, fat or body water.

If you weigh at least 20% more than your ideal weight, you are considered obese. To calculate your ideal weight, health professionals have suggested using your body mass index (BMI) as a rough indicator. If your BMI is 30 or above, you are considered obese.

Do keep in mind that this is a very rough gauge and having a higher than normal BMI does not necessarily mean you are unhealthy. Imagine bodybuilders! They are constantly building muscle, which means they are also putting on weight but it does not mean that their health is at stake.

Obesity can happen for many different reasons, such as consuming too many calories, leading a sedentary lifestyle and getting insufficient sleep. But regardless of the reason, being obese puts one in danger of certain illnesses, such as type 2 diabetes, high blood pressure and heart disease.

How obesity increases your risk for type 2 diabetes

People who are obese have a high risk of developing type 2 diabetes, which is also known as insulin-resistant or adult-onset diabetes. This is a condition where your blood glucose level is persistently high.

In obese persons, cells of fat tissues have to process more nutrients than they can manage. The stress in these cells triggers an inflammation that releases a protein known as cytokines. Cytokines then block the signals of insulin receptors, thus gradually causing the cells to become resistant to insulin.

Insulin allows your cells to use glucose (sugar) for energy. When you are resistant to insulin, your body is unable to convert the glucose into energy and you end up with a persistently high blood glucose level.

Besides suppressing normal responses to insulin, the stress also triggers inflammation in cells that can lead to heart disease.

The link between diabetes and heart disease

Compared to people without diabetes, people who have diabetes are at higher risk for severe heart disease, such as coronary heart disease, heart failure or diabetic cardiomyopathy (heart muscle disorder).

Coronary heart disease (CHD)

In CHD, a fatty substance builds up inside the coronary arteries that supply your heart with oxygen-rich blood. This results in narrowed coronary arteries and reduces blood flow to your heart muscle.

The fatty deposits also increase the likelihood of blood clots forming in your arteries, which either partially or completely block blood flow.

CHD can lead to chest pain, an irregular heartbeat, a heart attack or even death. CHD can also lead to heart failure by weakening the heart muscle over time.

Note that heart failure does not mean that your heart has stopped. It means your heart is unable to pump enough blood to meet your body’s needs, thus requiring medical attention.

Diabetic cardiomyopathy

Diabetic cardiomyopathy is a disease that damages the structure and function of the heart. This disease can lead to heart failure and an irregular heartbeat in people who have diabetes but do not have CHD.

How obesity increases your risk of high blood pressure

In obese individuals, the heart has to work extra hard to pump blood throughout the body, as a result of fatty substances accumulated in the arteries. This condition is called hypertension, where blood pressure on the inner walls of the arteries is very high. Individuals who experience abdominal obesity, where body fat is accumulated at the abdominal area, are likely to develop hypertension.

The link between high blood pressure and heart disease

Various heart disorders may occur when the heart consistently works under increased pressure.

Hypertensive heart disease is the number 1 cause of death associated with high blood pressure. It includes a group of disorders, such as heart failure, ischemic heart disease and left ventricular hypertrophy (excessive thickening of the heart muscle).

Ischemic heart disease

High blood pressure can cause ischemic heart disease, which is usually the result of a hardening of the arteries, otherwise known as coronary heart disease. This means that the heart muscle is unable to get enough blood as the pathway is blocked.

Left ventricular hypertrophy

Left ventricular hypertrophy is the enlargement and thickening of the walls of your heart’s main pumping chamber (left ventricle). The condition may develop due to high blood pressure or a heart condition.

In fact, high blood pressure is the most common cause of left ventricular hypertrophy. More than ⅓ of people show evidence of left ventricular hypertrophy when they are diagnosed with hypertension.

Article reviewed by Dr Ooi Yau Wei, cardiologist at Mount Elizabeth Novena Hospital.


Obesity - Topic Overview. (n.d.). Retrieved August 20, 2017, from http://www.webmd.com/diet/obesity/tc/obesity-overview#1

What is Obesity? (n.d.). Retrieved August 20, 2017, from http://www.medicalnewstoday.com/info/obesity

Obesity: MedlinePlus. (n.d.). Retrieved August 20, 2017, from https://medlineplus.gov/obesity.html

Diabetes and Obesity. (n.d.). Retrieved August 20, 2017, from http://www.diabetes.co.uk/diabetes-and-obesity.html

Mandal, M. D. (2017, August 03). Obesity and Blood Pressure. Retrieved August 20, 2017, from https://www.news-medical.net/health/Obesity-and-Blood-Pressure.aspx

Obesity Action Coalition » Hypertension and Obesity: How Weight-loss Affects Hypertension. (n.d.). Retrieved August 20, 2017, from http://www.obesityaction.org/educational-resources/resource-articles-2/obesity-related-diseases/hypertension-and-obesity-how-weight-loss-affects-hypertension

About The Heart & Heart Disease. (n.d.). Retrieved August 20, 2017, from http://www.myheart.org.sg/resources/about-the-heart-and-heart-disease/1/15

Why Does Obesity Cause Diabetes? (n.d.). Retrieved August 20, 2017, from http://www.medicinenet.com/script/main/art.asp?articlekey=39840

Signs of Insulin Resistance. (2017, August 17). Retrieved August 20, 2017, from http://www.healthline.com/health/diabetes/insulin-resistance-symptoms

High Blood Pressure and Hypertensive Heart Disease. (n.d.). Retrieved August 20, 2017, from http://www.webmd.com/hypertension-high-blood-pressure/guide/hypertensive-heart-disease#1

What Is Diabetic Heart Disease? (2011, September 20). Retrieved August 20, 2017, from https://www.nhlbi.nih.gov/health/health-topics/topics/dhd

Left ventricular hypertrophy: When heart muscle thickens. (2015, June 06). Retrieved August 20, 2017, from http://www.mayoclinic.org/diseases-conditions/left-ventricular-hypertrophy/basics/causes/con-20026690

Ooi Yau Wei
Mount Elizabeth Hospital

Dr Ooi Yau Wei is a cardiologist practising at Mount Elizabeth Novena Hospital, Singapore. He specialises in interventional cardiology and has special interests in complex coronary intervention.

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