Beyond BMI: The Role of Weight in Health Outcomes

Shanthi Appelö

| 4 min read

Shanthi Appelö is a registered dietitian and health ...

One of the most common components of a preventive care screening is being weighed on a scale. This measurement is used by health care providers to calculate a person’s body mass index, a standardized way to quickly evaluate a person’s health status and risk for chronic conditions.
The body mass index (BMI) is a value based on how a person’s weight relates to their height:
  • Below 18.5 is underweight
  • 18.5–24.9 is a healthy range for most adults
  • 25–29.9 is an overweight range
  • 30 or above is considered obese
Nearly one in three adults (30.7%) are considered overweight and more than two in five adults (42.4%) are considered obese by BMI standards. However, these statistics do not take into account the other factors that affect how healthy a person truly is.

Limitations to BMI

The BMI system has been criticized for its limitations. It does not consider a person’s body composition, which includes the ratio of excess fat, muscle or bone mass on a person, or how fat is distributed on a person’s body. This is why some experts recommend also taking a measurement of the circumference of a person’s waist as an additional screening tool.
BMI also doesn’t account for factors including:
  • Age
  • Ethnicity
  • Eating habits
  • Gender
  • Physical activity
  • Race

Health is more than BMI

The factors that determine a person’s health can vary – which means BMI is only one variable to consider. Other factors include:
  • Blood pressure: The higher a person’s blood pressure is, the more at risk they are for additional health problems, including heart disease, heart attack and stroke.
  • Cholesterol: While some cholesterol is needed for the body to be healthy, too much LDL cholesterol can cause fatty deposits to build up in blood vessels. This makes it difficult for blood to flow through arteries. These deposits can also break off suddenly, forming a clot that could contribute to a heart attack or a stroke. 
  • Family history and genes: How a person stores fat on their body – and how much fat they store on their body – may be strongly connected to their genes. They also may determine appetite.
  • Lifestyle habits: Getting enough physical activity, eating a balanced, nutritious diet and taking care of mental health are all significant health factors.
  • Mobility: The ability of a person to move freely and easily is a key consideration for healthy aging. It covers many aspects of daily life – getting out of bed, walking around the house, sitting in a chair, walking for exercise and completing daily chores; as well as the ability to work, play, drive a car or use another form of transportation. Reduced mobility is connected to negative health outcomes.
  • Sleep habits: Getting seven to eight hours of sleep each night is recommended for adults. Not enough sleep is connected to poorer diet choices and may make health conditions worse.
  • Social determinants of health: More than 80% of what goes into how healthy people are, isn’t driven by the medical care they receive but by social determinants of health, which include where you live, access to healthy food, housing instability, income, education, food insecurity, access to health care, health literacy, crime and violence and environmental conditions of your home and neighborhood.

Small changes can affect health

Weight is not the only factor affecting a person’s overall health and wellness. However, small changes in weight can positively affect other health factors.
A recent study found that if individuals lose 5% of their overall body weight, they see improvement in other factors that affect overall health and well-being:
  • Better sleep
  • Improved mood
  • Less strain on joints
  • Lower cholesterol 
  • Lower blood pressure
  • Decreased body fat
  • Improved insulin sensitivity, lowering risk for Type 2 diabetes
Individuals can talk with their health care provider about the factors in their lives – like how active they are, family history, where they live or work, their sleep habits and their blood pressure – to get a more complete picture of their overall health in comparison to their height and weight. 
Shanthi Appelö is a registered dietitian and health and wellness spokesperson at Blue Cross Blue Shield of Michigan.
MI Blues Perspectives is sponsored by Blue Cross Blue Shield of Michigan, a nonprofit, independent licensee of the Blue Cross Blue Shield Association