The link between obesity, inactivity and heart disease has a lot to do with the conditions that often come with obesity: High blood pressure, high LDL cholesterol and triglycerides, and low HDL cholesterol, sleep apnea and Type 2 diabetes. 

Published: January 25, 2019 | Updated: September 19, 2024

A high body mass index, or BMI, and a sedentary lifestyle increase your risk for heart disease. It’s important to understand how these two factors impact your heart and what you can do to decrease your risk for developing heart disease.

What is BMI?

BMI is a screening tool used to measure body fat. You fall into one of four categories based on your BMI: underweight; normal or healthy weight; overweight; or obese. These categories are used with other health assessments to determine your risk for certain chronic illnesses, including heart disease. BMI is calculated using the following formula:

[Weight / (Height in inches)²]X 703

Here’s how you would calculate your BMI if you weigh 150 pounds and are 5 feet, 5 inches (or 65 inches) tall:

[150 ¸ (65)²] X 703 = 24.96

If you don’t care for math, there are many free BMI calculators online. While the BMI measurement is an accurate screening tool for most people, it may be less accurate for some groups, such as athletes.

What is a healthy BMI?

It’s helpful to use a BMI chart to understand what your BMI number means.

According to a 2018 report from United Health Foundation, over 31 percent of U.S. adults are obese. Obese adults have a higher risk for many diseases, including heart disease, and conditions that increase your risk for heart disease, such as high blood pressure, cholesterol, diabetes and sleep apnea.

How is your activity level related to your BMI?

Maybe you’ve used a fitness or calorie tracker that asked you to choose your activity level. You generally choose from four or more categories to describe activity: sedentary, lightly active, moderately active and extremely active. You may be tempted to choose a higher level of activity, but over one-quarter of U.S. adults are considered sedentary. These categories consider the intensity of your activity, as well as the frequency and types of activities you do on a weekly basis.

An active lifestyle that includes frequent exercise is important for weight loss and weight maintenance. Weight loss lowers your BMI, and remaining active can help keep it within a healthy range. The recommended amount of activity is 150 to 300 minutes per week of moderate-intensity physical activity.

How do high BMI and inactivity put you at risk for heart disease?

The link between obesity, inactivity and heart disease has a lot to do with the conditions that often come with obesity. These include high blood pressure, high low-density lipoprotein (LDL) cholesterol and triglycerides, and low high-density lipoprotein (HDL) cholesterol, sleep apnea and Type 2 diabetes. These conditions also are links to heart disease. Essentially, obesity increases your risk for heart disease and other serious health conditions.

There are other ways obesity affects your heart. Inflammation triggered by obesity can increase the buildup of plaque in artery walls and increase the chance that the plaque will rupture, leading to a heart attack. Obesity also raises your risk for developing atrial fibrillation, a condition that can lead to blood clots, stroke, heart failure or other heart complications. Finally, extra weight from obesity puts added stress on the heart, causing it to weaken over time.

A high BMI and sedentary lifestyle also increase your risk for heart failure.

“Diseases that damage the heart — including coronary artery disease, high blood pressure and diabetes — are common causes of heart failure. Smoking, obesity, eating foods high in fat and sodium, and physical inactivity also increase your risk,” said John S. Harris, M.D., cardiologist with Norton Heart & Vascular Institute Advanced Heart Failure Porgram. “Heart failure becomes more common with age and is one of the most common reasons for admissions to the hospital.”

How can I decrease my risk for heart disease?

High BMI and inactivity have serious and detrimental effects on your heart and overall health. But there’s good news. Obesity and inactivity are reversible, and you can make changes that will reduce your risk for heart disease and other conditions.

These are steps you can take to reduce your risk for developing heart disease:

• Aim to reach a BMI within the healthy/normal range.
• Lose some weight, even if it doesn’t put you in the normal BMI range.
• Strive to get 150 to 300 minutes per week of moderate-intensity physical activity.
• Increase your physical activity by any amount, even if it’s not within the recommended amount. Moderate-intensity activities may include a brisk walk, water aerobics, bicycling, tennis or ballroom dancing.

Research shows that small changes have an impact on your health and risk. Consider these findings from the 2018 Physical Activity Guidelines Advisory Committee:

• A single session of moderate to vigorous exercise reduces blood pressure, improves insulin sensitivity, improves sleep and reduces anxiety symptoms — all conditions that are linked to heart disease.
• Most improvements increase with regular moderate to vigorous exercise sessions.
• Benefits, such as a reduced risk for some diseases, occur within days or weeks of incorporating a physical activity routine.
• Regular moderate to vigorous physical activity reduces the risk of several cancers, including bladder, endometrium, esophagus, kidney, lung and stomach.