AFib: Why Weight Loss Helps

Medically Reviewed by James Beckerman, MD, FACC on September 04, 2023
4 min read

More people than ever have an abnormal heart rhythm, or what doctors call atrial fibrillation (AFib). While family history and getting older can play a part, you can control something that can make you more likely to have AFib: your weight.

Whether you’re at risk for AFib or just want to improve your health, here’s what you should know.

About 5.6 million Americans have AFib. If you’re one of them, your heart isn’t getting the right electric signals to tell it when to contract or relax. As a result, the upper chambers can’t beat in a normal pattern and your heart can’t pump blood as well as it should.

AFib can cause weakness, shortness of breath and heart palpitations, when you feel like your heart has skipped a beat. It might feel fluttery, or like it’s racing or pounding. AFib also raises your odds of more severe health problems, like stroke, kidney disease, and heart failure.

If you’re obese -- meaning you have a body mass index (BMI) of 30 or higher -- you’re twice as likely to have AFib.

But you can turn things around. Losing extra weight can make a difference. In one study, obese people who shed at least 10% of their body weight were 6 times less likely to have this abnormal heartbeat again.

Extra fat, especially around your waist, has a direct effect on your heart. Over time, it can build up in your arteries and damage your heart’s left ventricle (its main pumping chamber.) This prevents it from filling up as much as it needs to between beats.

Excess weight also causes electrical and chemical changes to your heart. It can raise the amount of inflammation in your body. Plus, when you’re obese, you’re more likely to have other health issues, such as hypertension, coronary artery disease (CAD), sleep apnea, and diabetes. Each of these is linked to increased AFib risk, too.

The higher your BMI, the more likely you are to have AFib.

Sometimes, doctors can treat AFib with drugs that reset your heart’s rhythm. If you can’t take medicine or it doesn’t work, surgery is an option.

Cardiac ablation is a common AFib treatment. During this surgery, the doctor threads a long tube called a catheter through your blood vessels and up to your heart. Then they use radio waves, heat, or extreme cold to destroy the damaged tissue that’s causing your AFib.

Although ablation takes away the need for long-term medicine or a surgical implant to correct your heartbeat, it’s less likely to be a good option if you’re obese. The odds that your AFib will come back after this treatment are higher than for someone with a normal BMI. Even small increases in BMI can raise the odds. And if your BMI’s over 40, you’re also more likely to have side effects from a cardiac ablation.

So what’s the best thing to do if you’re obese and likely to have AFib? Experts believe the answer is weight loss.

Getting to a healthy weight will also help manage other health problems like blood pressure, sleep apnea, diabetes, and hyperlipidemia (high cholesterol). Once those are under control, your heart should work better, too.

Eat less, move more. Lower the amount of calories you eat and drink. Raise your exercise. Your doctor can tell you how to do this safely.

Focus on healthy foods. Fresh, whole foods like fruits, vegetables, and whole grains give your body the nutrients it needs without extra calories.

Start small. Choose goals that are clear and easy to reach -- you’re more likely to stick to them. Here’s a good one: Say you’ll cook a healthy dinner and skip fast food two nights this week.

Track your progress. Log your food, count your steps, and check in often with a friend or counselor.

Be patient. Weight loss takes months and sometimes years, not days. Aim for a lifestyle change you can sustain for the long run, rather than a crash diet that leaves you feeling deprived.

Talk to your doctor. If you’re obese, you may need more than diet and exercise to shed your extra pounds. Bariatric surgery (which makes your stomach smaller or makes changes to your small intestine) can help your heart, too. Your doctor will let you know if that’s an option for you.