In almost any article about healthy living, it will mention that managing your weight is critical for your overall health. That is because extra weight impacts your heart.

The link between weight and heart health

The heart has a big job: to pump blood throughout the body. The larger the body, the harder the heart must work to pump and circulate the blood. Extra weight also gives the body volume, which creates more resistance for the heart to overcome as it pumps. The larger volume and increased resistance can result in the heart having to work much harder almost all the time.

Because the heart is primarily made of muscle, all that extra work takes its toll. It causes the muscle to enlarge. This can result in a condition called left ventricular hypertrophy (LVH), which means an enlargement of the left side of the heart. LVH is also associated with other cardiac issues that affect your health, including:

  • Hypertension. Hypertension, or high blood pressure, is a common condition that can exacerbate LVH.
  • Arrhythmias.  When the heart beats in abnormal or irregular patterns, it is called an arrhythmia. With LVH, arrhythmias can be dangerous and even life threatening.
  • Cardiomyopathy. Another condition called cardiomyopathy involves a weakened heart muscle that cannot pump as efficiently as it should. This is sometimes seen with LVH and can affect quality of life by causing congestive heart failure. This results in significant shortness of breath and fluid build-up (edema). It can also be associated with sudden death.

The right side of the heart may also enlarge because of obesity, and this is known as right ventricular hypertrophy. This condition is associated with other medical problems, including obstructive sleep apnea, pulmonary hypertension and right-sided congestive heart failure.

Determining a healthy weight

In order to maintain a healthy weight, you must first determine what that healthy weight is. Normal weight is often determined by a measure called body mass index, or BMI. This calculation is determined by an algebraic calculation which is weight in kilograms divided by height in meters squared. But there are many calculators like this one from the CDC readily available to do it for you.

In general, a BMI of 21 to 25 is normal weight, between 25 and 30 is overweight; more than 30 is obese. There are also specific categories of obesity defined by BMI, including “extreme obesity” at 40 or greater.

There is something to keep in mind about BMI. The formula does not account for other variables, such as gender, age or muscle mass. That means every person who is the same height and weight has the same BMI. As BMI does not always present an accurate representation of a healthy weight for each individual, it may not be the best way to determine healthy weight.

While BMI can be used as a starting place, other methods may be more appropriate and practical for determining a healthy weight for each individual. Working with a registered dietitian or cardiovascular health program can help determine a healthy weight goal that is more accurate and more appropriate for an individuals height, gender, age and other variables.

Obesity and heart disease

Obesity, a condition marked by excessive body fat and a BMI of greater than 30, is associated with increased frequency of coronary artery disease. Other conditions that contribute to heart disease include high cholesterol, high blood pressure, and diabetes. All of these conditions are seen more frequently with obesity and result in more heart attacks and congestive heart failure, as well as shorter life expectancy.

Prior to 1997, the presence of these illnesses in the obese population was blamed for the increase in heart disease. But in 1997, the American Heart Association declared obesity itself an independent risk factor for heart disease. Simply put, this means obesity alone puts you at greater risk for heart disease even if those other illnesses are not present.

A 2014 National Institutes of Health study demonstrated that in high level obesity, a BMI of greater than 40, there is a significant increase in early mortality from heart disease, stroke, diabetes, liver disease, kidney disease and certain cancers. The National Institute on Aging reports that individuals suffering from obesity on average have a life expectancy of five years less than people who are in the “normal” weight category. Another study published in Lancet concludes that life expectancy decreases from one year in low level obese individuals to 10 years in those with severe obesity, with a three times greater risk in men.

Losing weight for heart health

To lose weight and improve heart health, you must do three things:

  • Adjust your caloric intake.
  • Change your diet.
  • Be more physically active

Successful weight loss is not just a matter of cutting calories—nutrition is the key. A professional nutritionist is your best guide for adjusting your caloric intake and can help you develop a nutrition protocol that’s right for your individual needs.

A nutrition protocol, or healthy eating plan, allows you to lose weight while also providing all of your recommended nutritional needs. If you are trying to improve your weight and cardiac health, the nutrition protocol must also be adjusted to typically lower triglycerides and cholesterol. Increasing activity is also beneficial in improving heart health.

Before beginning any physical activity, be sure to discuss it with your doctor or health care professional. If your provider approves you to start a new exercise program, working with a professional trainer or exercise physiologist can be helpful.

Wen-Chih "Hank" Wu, MD

Dr. Wen-Chih Wu, MPH, is director of the Lifespan Cardiovascular Wellness and Prevention Center at the Lifespan Cardiovascular institute and specializes in the prevention of cardiovascular diseases and diabetes.