Overweight and obesity in heart failure

People often describe body weight in different ways—some might say someone looks "slim," "average," or "a bit heavy." But to get a clearer picture of whether someone’s weight is healthy, doctors use a tool called the Body Mass Index (BMI).

BMI is a simple calculation that compares your weight to your height. It helps to show whether you're in a healthy weight range. According to the NHS:

• Underweight: BMI below 18.5
• Healthy weight: BMI between 18.5 and 24.9
• Overweight: BMI between 25 and 29.9
• Obese: BMI between 30 and 39.9
• Severely obese: BMI of 40 or more

While BMI isn’t perfect—it doesn’t account for muscle or body shape—it’s a useful starting point for understanding your weight and health. If you're unsure about your BMI or what it means for you, your GP or nurse can help explain it and guide you on next steps.

Please, replace: We often hear that carrying too much weight is bad for our health—and in most cases, that’s true. But a few years ago, some studies suggested something surprising: people with heart failure who were overweight seemed to live longer than those with a “normal” weight. This idea became known as the “obesity paradox.”

However, more recent research has shown that this effect doesn’t apply to healthy people, and the benefits of being overweight in heart failure are still debated. According to the NHS and NICE guidelines, being overweight or obese is still considered a risk factor for developing heart problems in the first place.

That said, for people who already have chronic heart failure, the picture is more complex. Some studies have found that people with heart failure who are slightly overweight may have better survival rates than those who are underweight or even in the “normal” weight range. But this doesn’t mean gaining weight is a good idea. Instead, it highlights the importance of individualised care—what’s best for one person may not be right for another.

If you have heart failure, it’s important to talk to your doctor about your weight, your symptoms, and your overall health. Together, you can decide on the best approach for you.

Some studies have shown that people with heart failure who carry a bit of extra weight may live longer than those with a “normal” weight. This has led to what’s sometimes called the “obesity paradox.” But experts still don’t fully understand why this might happen—and it doesn’t change the fact that being overweight comes with serious health risks.

According to the NHS, carrying too much weight increases your risk of many long-term health problems, including:

• Type 2 diabetes
• High blood pressure
• Heart disease and stroke
• Fatty liver disease
• Joint problems like osteoarthritis
• Certain cancers, such as breast and bowel cancer
• Sleep apnoea
• And even heart failure itself

In simple terms, maintaining a healthy weight can help prevent heart failure and many of these other conditions. That’s why it’s still important to aim for a healthy weight—especially if you already have conditions like diabetes, high blood pressure, or coronary heart disease.

Even small, steady changes in your weight can make a big difference to your health and how you feel day to day.

Doctors are still learning exactly how different diets affect heart failure, but one eating pattern stands out: the Mediterranean diet. This heart-healthy way of eating is often recommended for people with heart failure because it supports the health of your heart and blood vessels.

The Mediterranean diet includes:

• Plenty of fruit and vegetables
• High-fibre foods like whole grains and legumes
• Less red meat, and more fish
• Healthy fats from olive oil and other vegetable oils, instead of butter or animal fats

If you have heart failure, there’s something else that’s especially important: watching your salt intake. Eating too much salt can cause your body to hold on to extra fluid. This puts more strain on your heart, which may already be struggling to pump properly. The result can be fluid build-up in your lungs or legs, known as oedema.

To help manage your symptoms, your doctor may also recommend limiting how much fluid you drink each day. This can help prevent your heart from becoming overwhelmed.

In short, eating a balanced, low-salt diet like the Mediterranean diet can help you feel better and reduce the risk of complications from heart failure.