What is the Link Between Obesity and Hypertension

What is Obesity?

Obesity is a medical condition that is characterised by the accumulation of excess fat in your body. It is defined as having a Body Mass Index (BMI) of 30 kg/m2 and above. You can calculate your BMI by using the following formula.

Body Mass Index = Weight in kilograms ÷ Height in meters2

It is a complex disorder that can adversely affect your metabolism and increase your risk of developing other health complications like heart disease, Type 2 Diabetes, high blood pressure, stroke, sleep disorders, mental health disorders, etc.

What is the Relationship Between Obesity and Hypertension?

When you are overweight or obese, your heart has to work harder to pump blood throughout your body. This extra effort puts strain on your arteries. In turn, your arteries resist the blood flow, causing your blood pressure to rise.

Being overweight or obese also raises your chances of having too much low-density lipoprotein (LDL or “bad”) cholesterol in your blood. This raises your chances of cardiovascular diseases, as excess cholesterol can stick to the walls of your arteries that are damaged by hypertension. This is known as plaque formation, which can make your arteries clogged, stiff, and narrow. 

When blood flows through narrowed and clogged arteries, it exerts more pressure on your artery walls, thus elevating your blood pressure levels.

What is Obesity-Induced Hypertension?

High blood pressure that is primarily caused by an increase in your body weight is known as obesity-induced hypertension. 

Why Does Obesity Cause Hypertension?

Obesity can alter the functions of several organ systems in your body. Some of these changes can lead to an elevation in your blood pressure levels. Obesity-induced hypertension is thought to be caused by the following mechanisms.

• Sympathetic nervous system activation

Your Sympathetic nervous system (SANS) is responsible for the “fight or flight” reaction you experience when you are under physical or mental stress. Studies have shown that obesity can lead to the continuous activation and overstimulation of SANS When activated, your SANS releases stress hormones like cortisol, epinephrine (adrenaline), norepinephrine, etc. to deal with the stressor.

Stress hormones can increase your blood pressure in the short term by causing your heart to beat faster and contracting your blood vessels. Long-term stress and SANS activation can lead to poor mental health and bad coping mechanisms like binge eating, lack of exercise, smoking, alcohol consumption etc., which can contribute to raised BP levels.

• RAAS activation

Obesity and SANS activation can lead to increased production of the hormone renin. Renin is a hormone that causes a chain reaction called the Renin-Angiotensin-Aldosterone System (RAAS) cascade, which can elevate your blood pressure levels. The RAAS cascade can increase the amount of sodium and water reabsorbed from your urine, which can increase your blood volume and thus your blood pressure. The RAAS cascade also triggers the release of hormones that can constrict your blood vessels, leading to increased blood pressure levels.

• Sodium retention

Obesity can result in increased sodium retention in your body. This can be caused by several factors like the physical compression of your kidneys by fat tissue or the activation of the SANS and RAAS cascade. These factors can impair the normal functioning of your kidneys. This results in your kidneys retaining the sodium that should be excreted through your urine. Your body retains more water and fluid in order to balance out the excess sodium in your blood, leading to increased blood volume and blood pressure.

Can Weight Loss Improve Your Blood Pressure Levels?

Weight management is an important aspect of hypertension treatment. Several studies conducted over the years suggest that losing even one kilogram (2.2 pounds approx.) of weight can help lower your blood pressure to some measure. The more weight you lose, the bigger improvement you can see in your blood pressure levels. 

The US National Institutes of Health (NIH) recommends maintaining a BMI between 18 to 25 kg/m2, and ensuring your waist measurement is below 35 inches if you are a woman, or below 40 inches if you are a man with hypertension.

How Can You Prevent or Manage Obesity?

• Eat balanced and healthy meals

Diet is one of the, if not the most important component of weight management. The key to losing weight is to burn more calories than you eat. So no matter how much you exercise, you cannot lose weight without having a healthy diet plan and watching what you eat. If you have hypertension, following a modified, low-calorie version of the DASH diet can help you tackle both hypertension and obesity.

Cutting out processed foods, junk food, food products with added sugar, etc. can help you lower your calorie intake. Replacing these foods with fresh fruits and vegetables, whole grains, nuts, seeds, lean meat and other healthy foods can help you lose weight sustainably.

Click here to learn how to lose weight faster and in a healthy way.

• Be physically active

Most health advisory boards like the CDC and NHS UK recommend at least 45 to 60 minutes of moderate-intensity exercise every day, at least 5 times a week to lose weight and prevent obesity. If you are a beginner who is not used to being physically active, start with 30 minutes of low-intensity activities like walking or home work-outs a day. Slowly switch to more intense activities like running, swimming, skipping, aerobics, cycling, etc. in order to burn more calories. 

Include resistance or strength training in your exercise regimen to improve bone strength and muscle function. Exercise can not only help you lose weight, but it can also improve your blood pressure control.

• Get good sleep

Getting at least 7 to 9 hours of sleep every night is crucial for good health. Sleep deprivation (getting less than 6 hours of sleep) for even one night can lead to an increase in your stress hormone (cortisol) levels, which can negatively affect your blood pressure.

Loss of sleep and high cortisol levels can also trigger the release of the hunger hormone, ghrelin, which can cause you to overeat. This can result in weight gain.

• Manage stress

Stress is a significant contributor to obesity. Long-term stress can lead to unhealthy coping mechanisms like binge-eating and stress-eating, which can lead to obesity. Stress also triggers cortisol production, which can slow down your metabolism, leading to fewer calories being burned.

Stress and increased cortisol levels can also directly affect your blood pressure levels and lead to the worsening of your condition.

Hence, it is important to manage your stress in a healthy way by relaxing, meditating, and practising mindfulness. If you are feeling overwhelmed, consider reaching out to a mental health professional.

• Quit smoking

Though light smoking can reduce your appetite and cause you to burn more calories, heavy smoking is associated with metabolism disruption and an increased risk of obesity. 

The nicotine and carbon monoxide in cigarettes can harden your blood vessels and lead to plaque formation. Thus smoking can have a detrimental effect on your blood pressure.