BMI – One factor for determining metabolic risk

Body Mass Index (BMI) is a straightforward and useful tool for assessing metabolic health. While it’s widely recognised to be a simplified and blunt measure, BMI provides a solid starting point for understanding potential health risks.

We often receive feedback from Advisers relating to the underwriting of BMI. As underwriters, we use BMI as a starting point to identify if we need more information for further analysis, rather than the be all, end all.

BMI is a quick and simple tool to estimate whether someone is broadly underweight, a healthy weight, overweight or obese. It’s calculated as weight (in kilograms), divided by height (in metres), squared. 

BMI calculators are available online and can be accessed via a simple Google search.  According to the World Health Organisation (WHO), the general BMI categories are: 

• Underweight: <18.5
• Normal weight:  18.5 – 24.9 
• Overweight: 25 - 29.9 
• Obesity (class 1): 30 – 34.9 
• Obesity (class II): 35 – 39.9 
• Obesity (class III): ≥ 40 

Metabolic risk describes the risk associated with an applicant’s metabolism (ie how a person’s body processes and stores energy).

Metabolic risk is a key indicator of cardiovascular health, diabetes risk and associated complications such as kidney disease, neuropathy and retinopathy. It can also act as an indicator of conditions like fatty liver disease as well as some cancers. It’s closely associated with morbidity (risk of associated illness, disease or disability) and mortality (risk of associated death).

As underwriters it’s vital to understand all key indicators of metabolic risk to create a holistic profile of an applicant’s health.

BMI is just one indicator of metabolic risk, alongside high blood pressure (hypertension) and blood sugar/insulin resistance (diabetes or pre-diabetes).

If a customer’s BMI is over a certain threshold they may be required to undertake additional tests to help us accurately assess their metabolic risk. This can include:

• a blood test to determine their lipids, diabetes risk and liver function.
• a medical exam to assess body weight distribution. Weight centralised around the stomach (known as “abdominal obesity”) can be an indicator of ongoing conditions such as cardiovascular complications, liver disease, sleep apnoea, and increased cancer risk. 
   

These extra assessments provide us with a more accurate view of metabolic risk. For example, if an applicant has a high BMI but very well controlled blood pressure and blood results, we can apply the appropriate credits.

Our team work to tailor the underwriting assessment to each individual. A high BMI indicates that we need to request additional tests to help us understand whether an applicant’s metabolic risk falls into the “standard” risk category for their age and sex, or if it requires additional terms.