The Link Between Obesity And Hypertension

Cases of obesity are rising in the US and the rest of the world, causing chronic diseases like stroke, type 2 diabetes, osteoarthritis, heart disease, and hypertension (high blood pressure). With over 40%¹ of American adults considered obese, the disease is now referred to as an epidemic² with far-reaching health consequences.

High blood pressure itself can lead to heart attacks and strokes, making obesity one of the leading risk factors for illness and death.

Understanding obesity and hypertension and how they are linked is the first step to lowering your risk and protecting your health.

What is hypertension?

Hypertension is the medical term for high blood pressure. Blood pressure is the amount of force the blood exerts against the walls of the arteries. It is normal for blood pressure to rise and fall slightly throughout the day, but blood pressure is considered high when it stays elevated for too long.

Blood pressure is measured by looking at systolic pressure and diastolic pressure. Systolic pressure is the amount of pressure in the arteries that occurs when the heart contracts, while diastolic pressure is the arterial blood pressure measured between beats when the heart relaxes to refill with blood. Normal blood pressure is 120/80mm³Hg.

Hypertension complications

Hypertension increases the pressure on your arteries which can damage them and your organs. If your blood pressure is out of control for a long time, it can cause the following conditions:⁴

Stroke

High blood pressure leads to atherosclerosis (hardened, thickened, and narrowed arteries), a condition that causes complications such as stroke and a heart attack.

Heart failure

Since the heart has to put in more work to pump blood at high pressure through your blood vessels, hypertension can cause left ventricular hypertrophy (thickened muscles in the heart’s main pumping chamber). These thickened muscles may eventually struggle to pump enough blood to the body’s organs, which could cause heart failure.

Hypertensive retinopathy 

High blood pressure can damage the blood vessels in your eyes, which can cause blindness.

Dementia

Due to its impact on small blood vessels in the brain, chronic hypertension is associated with an increased risk of cognitive impairment and dementia in older people.⁵

What is the link between obesity and hypertension?

The relationship between obesity and high blood pressure is undeniably strong. Studies⁶ report that around 15% of people with normal weight in the US have hypertension, but that figure rises to 25% for overweight people and 40% for people with obesity.

A study⁷ found that obesity counted for 65% of the risk of developing high blood pressure in women and 78% for men. 

Overall, estimates suggest that at least 75%⁸ of high blood pressure cases are somehow linked to obesity.

How does obesity cause hypertension?

The exact nature of the link between obesity and high blood pressure is complicated and there are many factors. Obesity can cause hypertension⁹ in the following ways:

Sympathetic nervous system

Eating a high-calorie diet (particularly one containing lots of fat and carbohydrates), stimulates receptors in the nervous system that elevate sympathetic nervous activity (your involuntary responses). Increased fat around the abdomen and trunk area also activates the sympathetic nervous system. When this happens, blood vessels constrict and blood pressure rises as a result.

Free fatty acids

People with obesity have more free fatty acids, causing the blood vessels to become more sensitive which leads to elevated blood pressure.

Leptin

Leptin is known as a satiety hormone. It regulates your energy levels, tells you if you should feel hungry or full, and increases sympathetic nervous system activity. Increased fat tissue in the body elevates the amount of leptin released into the bloodstream. This decreases the blood vessels’ ability to dilate, causing blood pressure to rise.

Adipose tissues

A high volume of adipose tissue (body fat) raises the amount of glucocorticoids (a type of steroid) acting in your body. When this happens, the renin-angiotensin-aldosterone system (a hormone system that regulates blood pressure) becomes more active, which raises blood pressure.

Insulin resistance

Obesity creates a chronic state of systemic inflammation and insulin resistance, which stops the artery walls from working properly. This makes the arteries narrow, causing high blood pressure.

Insulin resistance and metabolic syndrome (a combination of obesity, high blood pressure, and diabetes) are common in obese people and increase the activation of the sympathetic nervous system, causing high blood pressure.

When the body becomes resistant or less sensitive to insulin, a large amount of insulin is secreted into the bloodstream to compensate. High blood pressure occurs because the body still can’t use that insulin, resulting in a state of hyperinsulinemia in obese people. High insulin levels reduce the kidney’s ability to reabsorb salt, causing high sodium and water volume to be retained in the body, which leads to high blood pressure.

Obstructive sleep apnea

Obesity raises your risk of experiencing obstructive sleep apnea, which stimulates the sympathetic nervous system and leads to high blood pressure.

Other risk factors for high blood pressure

In addition to obesity, the following are additional risk factors for high blood pressure:

1. Age — your risk of developing high blood pressure increases as you grow older

2. Racial background — hypertension is more prevalent in African-American people than it is in white people

3. Family history — having one or more close family members diagnosed with hypertension before the age of 60  is a risk factor for developing  hypertension

4. High salt intake — consuming lots of salt leads to water retention and high blood pressure

5. Smoking —this not only raises your blood pressure temporarily, but the chemicals in tobacco can damage the inner lining of your arteries causing them to narrow and increasing your risk of high blood pressure and heart disease

6. Alcohol —heavy drinking (regularly consuming more than the recommended daily amount of one drink a day for women and two for men) can damage your heart

7. High-stress levels — stress and anxiety can cause your blood pressure to spike

8. Chronic conditions — specific chronic conditions such as kidney disease, sleep apnea, and diabetes can increase your risk of developing high blood pressure

How to avoid obesity and high blood pressure

There are steps you can take to reduce your risk of becoming obese and developing high blood pressure, including:

1. Make small changes that are easy to stick to

Your goal should be to make lifestyle changes that are easy to stick to for life — but remember that there’s a big difference between making lifestyle changes and going on a diet. Extreme diets give you quick results but are impossible to maintain and can damage your body.

Here are some of the risks of crash-dieting:

• New health problems

• Vitamin deficiency

• Losing muscle mass

• Regaining weight

Making small changes that are easy to stick to is recommended.

2. Eat healthily

To avoid obesity and high blood pressure, be mindful about what you eat. Consume a healthy, balanced, and nutrient-dense diet containing foods from each of the following groups:

• Fruits

• Vegetables

• Grains

• Lean proteins

• Nuts

Try to limit or avoid foods that contain lots of fat, sugar, and salt.

Consuming more calories than you burn causes excess fat to accumulate in your body. Research your ideal calorie intake for your age, sex, and lifestyle, and make healthier choices with simple swaps. 

For example, instead of drinking carbonated, sugary drinks, choose naturally flavored water or swap regular pantry essentials for low-salt options.

Most people don't consume enough fiber, but if you want to lose weight or prevent obesity, you should try to adopt a high-fiber diet with vegetables, fruits, and wholemeal foods. 

High-fiber foods also help you stay feeling fuller for longer because they release energy slowly, making you less likely to snack on unhealthy foods.

You might want to speak to your doctor or a nutritionist for specialist dietary advice that will help you improve your health and lose weight.

3. Exercise regularly

Getting 150 minutes of exercise a week¹⁰ is recommended to help prevent obesity and high blood pressure. You don’t need to exercise for 150 minutes on one day; you can break it down into manageable chunks.

Find simple and enjoyable ways to keep active, like taking a brisk walk, practicing yoga, or joining a dance class.

You don’t need to join the gym or get a personal trainer to get your body moving and improve your health and fitness.

Talk to your doctor before you start any new exercise regimen to check it’s safe for you.

4. Consider weight-loss surgery

Your doctor might recommend weight-loss (bariatric) surgery if other lifestyle strategies for losing weight haven't worked and you are at risk of serious health problems, including hypertension.

There are different types of weight-loss surgery, including sleeve gastrectomy and gastric bypass, but the surgery generally involves making changes to the stomach and small intestines so you consume less food.

Speak to your doctor and carefully review and discuss all your options if you are considering weight-loss surgery. This type of surgery comes with many possible complications and not everyone qualifies for it.

It’s also important to bear in mind that weight-loss surgery isn’t a magic solution to weight loss; you are more likely to see positive results if you maintain a healthy lifestyle before and after your surgery, otherwise, you might regain the weight you initially lose.

The lowdown

Obesity is a growing health concern in the US and around the world, and it is linked to primary hypertension. While the link between excess fat and high blood pressure is well-established, the mechanisms through which obesity leads to hypertension are many and complex.

Making healthy lifestyle choices to prevent weight gain or lose weight is the most effective treatment for obesity-related hypertension.

Extreme diets are dangerous as they not only deprive the body of essential nutrients and minerals but are also unsustainable in the long run. 

If you are concerned that your weight may be causing your blood pressure levels to rise, talk to your doctor so that you can both work on the most effective lifestyle changes for you.