There is an epidemic of obesity in the United States. As of 2018, more than 2 in 5 (42.4%) adults were obese. Obesity doubles the risk of developing atrial fibrillation (AFib). The epidemic of obesity is projected to worsen over the coming decades. As more people experience weight gain and become obese, we can expect the prevalence of atrial fibrillation to increase as well. But, can losing weight stop heart palpitations?
A recent weight loss study investigating weight loss amongst obese participants and its effect on their atrial fibrillation found that losing just 10% of body weight could help reverse AFib. Does this mean weight loss can cure atrial fibrillation? Not precisely. There is no actual cure for the abnormal heart rhythm (arrhythmia) that is atrial fibrillation but weight loss can significantly decrease AFib burden and prevent progression from intermittent (paroxysmal) AFib to continuous (persistent) or permanent AFib. The opposite is also true and AFib usually worsens and progresses in the setting of weight gain.
A person is considered to be overweight or obese when the body weight is greater than what is considered normal for the given height. Overweight and obesity are measured using body mass index (BMI). The BMI is calculated using a person’s weight in kilograms divided by height in meters squared. Below are the BMI and weight classifications for adults over the age of 20 years.
|18.5-24.9||Normal, or healthy, weight|
|40+||Severe, or morbid, obesity|
You can use this BMI calculator available through the Center for Disease Control & Prevention (CDC) to determine your BMI.
BMI is an indicator of the amount of fat in the body. Typically a higher BMI means a higher percent body fat. A notable exception to this is someone with a lot of muscle mass, like a body-builder. Muscle weighs more than fat so a body-builder may have a misleadingly high BMI. For the rest of us non-bodybuilders, a higher BMI indicates a higher amount of body fat which is known to contribute to a variety of health problems.
Being overweight or having obesity increases the risk of atrial fibrillation. In fact, research has shown that people who are overweight have a 40% increased risk of developing AFib compared to their normal weight counterparts. The risk of AFib is even greater in the setting of obesity and the same study showed that people who are obese are 87% more likley to develop atrial fibrillation compared to people with normal weight.
Weight gain incrementally increases the risk of atrial fibrillation. Research on the effect of weight gain and increasing BMI on AFib has shown that for every 5 point increase in BMI the risk of developing atrial fibrillation increases by 20-30%.
People with obesity are twice as likely to develop atrial fibrillation (AFib) as those with a healthy body weight.
Obesity is an independent risk factor for atrial fibrillation. This means that obesity not only increases AFib risk by increasing AFib risk factors, like high blood pressure, diabetes and obstructive sleep apnea, but obesity, in and of itself, increases the risk of developing atrial fibrillation. The exact mechanisms by which obesity contributes to AFib are not entirely understood but are thought to include:
Atrial fibrillation does not cause weight gain. It can however indirectly contribute to weight gain. For example, beta-blockers are a common type of medication used to treat atrial fibrillation. Some people experience weight gain on beta-blockers. The amount of weight gain is fairly minimal and averages 2.6 pounds. Not all beta-blockers have the same effect on weight. Older beta-blockers like atenolol or metoprolol can lead to weight gain while newer beta-blockers, like carvedilol, do not affect weight. If you have noted weight gain after starting a beta-blocker, you can talk to your provider about trying a different beta-blocker. Note, if you abruptly gain weight after starting a new atrial fibrillation medication and develop swelling in feet/legs or new shortness of breath speak to your healthcare provider right away as this can be a sign of another heart problem, like heart failure.
Another indirect way that AFib can cause weight gain is by decreasing exercise capacity. Not everyone with atrial fibrillation experiences symptoms but amongst those who do, fatigue, decreased exercise capacity and shortness of breath are very common. Often, these symptoms cause people to become less active and to decrease exercise because they feel poorly when they try to exercise. If a person’s activity level decreases significantly but there is not a corresponding decrease in calories, weight gain will occur. Unfortunately, weight gain often worsens AFib risk factors and makes atrial fibrillation treatments less effective.
Sustained weight loss can help reverse the AFib arrhythmia and prevent AFib progression. The Reverse-AF study followed patients with obesity and atrial fibrillation over the course of 4 years. During that time, study participants took part in a weight loss program that used a motivational, goal-directed weight loss approach. They received specific dietary guidance, engaged in low-intensity exercise, maintained a daily dietary and exercise journal and received support counseling at frequent clinic visits. At the end of the 4 year study period, the participants who had lost at least 10% of their body weight were 6 times more likely to be AFib free without the need for AFib medications or procedures. Study participants who lost less than 10% of their body weight showed less improvement in their atrial fibrillation with only 22% of participants who lost 3-9% of their body weight and 13% of people in the less than 3% weight loss category experiencing freedom from AFib at the end of the study period.
Atrial fibrillation does not cause weight loss. However, AFib can sometimes be seen in conjunction with other conditions that cause weight loss. The two most common causes of this are extreme weight loss and an overactive thyroid.
Extreme weight loss such as that seen with starvation diets or anorexia nervosa can lead to atrial fibrillation. The dehydration, ketosis, and electrolyte imbalances which occur as a result of starvation can upset the delicate balance needed to maintain a normal heart rhythm and may lead to atrial fibrillation.
Hyperthyroidism is a disease in which the thyroid produces too much thyroid hormone. There are a number of consequences of having an overactive thyroid, two of which are weight loss and atrial fibrillation. If you develop symptoms of unintentional weight loss and heart palpitations you should see your healthcare provider. If hyperthyroidism is causing atrial fibrillation, treating the overactive thyroid can reverse the AFib.
Advanced heart disease, like severe heart failure, can cause unintentional weight loss. This is called cardiac cachexia. When heart function is severely limited the heart is unable to effectively pump blood through the heart chambers and out to the rest of the body. Therefore, the system gets backed up and fluid accumulates in the legs, abdomen, and lungs. Excess fluid in the abdomen can decrease appetite and make it harder for the body to absorb nutrients from food. With severe heart failure the body has to work very hard to function. For example, as fluid builds in the lungs, a person has to work harder to breathe which burns more calories. Heart failure can also increase the body temperature which also burns more calories.
Cardiac cachexia cannot be fixed just by eating more calories. If you have developed severe heart failure as a result of atrial fibrillation and have developed signs of cardiac cachexia, you will work closely with your healthcare team to treat the atrial fibrillation and heart failure. Treatment recommendations may include:
For some people, atrial fibrillation can be reversed with diet and exercise. The Reverse-AF study described above demonstrated the benefits of weight loss on atrial fibrillation. This study focused primarily on the effect of diet and weight loss on AFib. The Cardio-FIT study investigated the benefits of exercise and weight loss on atrial fibrillation amongst people with obesity and AFIb.
This study followed participants for 4 years and found that baseline fitness and subsequent improvements in cardiorespiratory fitness impacted atrial fibrillation occurence. During this study, people with obesity and atrial fibrillation participated in a physician-led exercise program. This program was designed to improve exercise capacity and lead to weight-loss. Almost 90% of participants who had minimal improvement in their exercise capacity experienced AFib recurrence. This is contrasted with AFib recurrence in only 40% of participants who had greater gains in fitness level.
Sustained weight loss is the best way to reverse the negative health effects of obesity. The goal of weight loss is actually weight management because losing weight is a journey not a one time destination.
The Reverse-AF study demonstrated that weight fluctuations decreased the benefits of weight loss on AFib. In the study, participants who experienced a 5% weight fluctuation (i.e. losing and then regaining weight) were twice as likely to have recurrence of atrial fibrillation when compared to their study counterparts whose weight remained stable.
People are most likely to achieve weight loss if they adopt sustainable lifestyle changes. Fad diets are rarely effective at maintaining weight loss over the long term because they are difficult to adhere to over time. They tend to contribute to what is referred to as yo-yo dieting in which a person repeatedly loses and gains weight and ultimately ends up weighing more than they did to begin with.
Maintaining an ideal body weight is not about starvation and deprivation. There is so much conflicting dietary advice available which can make it confusing to know what to eat. A healthy diet does not need to be complex or difficult. Studies that compare various diets have repeatedly found that the best diet is the one that you can stick to over time. The Mediterranean diet often gets top marks because it is sustainable. This makes sense because it is based on the diet of a food-loving culture that values eating a variety of food that is fresh and flavorful.
It takes additional time and preparation to eat a healthy, well-balanced diet but eating well does not mean that you need to spend the whole day in the kitchen. Here are some tips for making eating a healthy diet a realistic part of your life:
In addition to eating healthy food, being physically active is an important part of a healthy lifestyle. The American Heart Association recommends that adults get at least 150 minutes of moderate-intensity exercise per week. It is preferable for the exercise to be spread out over the course of the week which would translate to 20-30 minutes of exercise on most days. Getting 75 minutes of vigorous physical activity per week is an alternative to the 150 minutes of moderate-intensity exercise. In addition the AHA recommends that adults:
There are a number of risk factors for atrial fibrillation including age, gender, ethnicity, and family history that are not influenced by weight loss. However, weight loss does have a significant positive impact on modifiable AFib risk factors and can help decrease atrial fibrillation by multiple mechanisms:
Obesity is not the only cause of heart palpitations and atrial fibrillation. Therefore, losing weight is not guaranteed to reverse AFib. However, losing weight with the goal of maintaining an ideal body weight can help reduce AFib burden, improve the effectiveness of atrial fibrillation treatments and improve overall quality of life.