However, it is possible that a few extra pounds may not be as harmful to those over age 65 as they are for younger people. In fact, being underweight is something older people should avoid.

This article will discuss healthy weight ranges and BMI for older adults. It will also help you learn how BMI affects older adults and why it’s dangerous for older adults to be underweight.

How BMI Affects Older Adults

BMI is calculated by dividing your weight in kilograms by your height in meters squared. There are also plenty of online calculators and charts that can help you determine your BMI based on inches and pounds if you prefer.

Even though it is a biased measure, BMI is still widely used in the medical community because it’s an inexpensive and quick way to analyze a person’s potential health status and outcomes.

There are certain risks associated with having a high BMI at any age. These include heart disease, high blood pressure, diabetes, and stroke.

But a low BMI is also unhealthy, especially for older adults. This has led some experts—including the National Institutes of Health—to suggest that it may be a good idea for older adults to keep a BMI between 25 and 27.

Dangers of Low Body Weight

One of the largest studies that set out to determine just how much BMI affects the health of older adults was published in 2014 in the American Journal of Clinical Nutrition. Researchers combined BMI data from 32 previous studies. The analysis included 197,940 adult participants (all older than age 65) who were followed for at least five years.

The researchers concluded that there was a higher risk of death when BMI was below 23 or above 33.

Several studies have found that being underweight at age 65 was linked to poor health and shorter life expectancy. Being overweight or obese at 65 was only rarely linked to worse health outcomes or lower life expectancy compared to those who were at a healthy weight at age 65.

Sometimes, in fact, the overweight and obese study participants had better health outcomes.

A Korean study collected data based on interviews with 542 people who had an average age of 74. Scientists discovered that health-related quality of life factors, such as social functioning, emotional health, and pain, are not made worse by a higher BMI in older adults. Additional research suggests that older adults who do not have a low BMI enjoy more independence. In fact, a study published in the Archives of Gerontology and Geriatrics found that older adults with BMIs over 30 did not experience a decline in activities of daily living.

Despite this evidence, it does not mean older adults should become overweight or obese on purpose. Being overweight is linked to serious health problems that require ongoing medical treatment and interfere with independence.

Health Risks and Challenges

Being overweight or being underweight is a risk factor for several health conditions. Often, medical illnesses can lead to weight loss or weight gain—or they can make it harder to reach a healthy BMI.

Risks of Being Overweight

Many of the illnesses that can be caused or worsened due to high BMI develop over years.

Some of the conditions that obesity contributes to include:

Heart disease High blood pressure Diabetes Gallbladder disease Osteoarthritis Stroke Breathing disorders such as sleep apnea

Sometimes a chronic disease can make it harder to have a healthy weight. For example, if your heart disease makes you short of breath when you walk, you may be less active, and you can have a hard time losing weight.

Risks of Being Underweight

Being underweight increases the risk of developing health problems, including nutritional deficiencies that cause medical problems—such as osteoporosis and anemia.

And a low BMI decreases your chances of recovering from illnesses and infections. For example, underweight stroke survivors have worse outcomes than stroke survivors who are overweight or average weight.

You can inadvertently lose weight if you have a chronic disorder that is associated with poor nutrition. Many conditions, such as cancer, gastrointestinal disease, and neurological disease can prevent older adults from eating or absorbing nutrients. This may lead to a low BMI, often for the first time in their lives.

Scientific data doesn’t tell us what the ideal weight patterns are for a long life. But we do know from studying people who live to 100 that being a healthy weight seems to be an important part of living a long life.

Weight Maintenance Goals

When trying to stay healthy, you should work with your doctor to set the right goal for you. Despite what charts and calculators may say, the target BMI is not the same for everyone. You may need to factor in additional considerations.

If you have diabetes, for example, your doctor may recommend that you lose weight. But your doctor may ask you to try to eat more of certain foods if you have anemia.

As you get older, some situations make it more challenging to reach your target BMI.

These factors include:

Health issuesChanges in activity levelMedicationsMetabolism changes

As you face these challenges, you may need the help of a nutritionist. A nutritionist can guide you as you set your calorie goals. Nutritionists can also help you decide whether you need to take vitamin and mineral supplements.

If you lose too many pounds, it may be a sign that you have a health issue that your doctor needs to investigate. It’s important to take early action if you become underweight.

Summary

Your BMI is one of the indicators of your overall health. Doctors recommend most adults keep their BMI between 18 and 24.9. Adults with a BMI over 25 are considered overweight and a BMI over 30 is considered obese.

On the other hand, older adults do better if they have a BMI between 25 and 27. Research shows that adults over 65 who are underweight experience more health issues and shorter life expectancy.

A licensed nutritionist can help you determine the best diet plan for your health. They can also help you select vitamins and mineral supplements to improve your nutrition.

A Word From Verywell

Trying to keep a healthy BMI can be challenging. Some people struggle with being underweight, while others battle against being overweight. If you are an older adult and find that you are having problems keeping a healthy weight, talk to your doctor or nutritionist. They can provide you with the tools you need to eat the diet that’s best for your body and unique situation.