Body Mass Index (BMI) in Grand Rapids, Michigan

Body mass index (BMI) is a simple way to estimate whether your weight is in a range that is generally healthy for your height. In Grand Rapids, where residents experience long, cold winters and less outdoor activity during part of the year, understanding BMI and body fat can be especially important for preventing chronic disease.

Local healthcare systems such as Corewell Health (formerly Spectrum Health), Trinity Health Grand Rapids, Metro Health – University of Michigan Health, and Mercy Health regularly use BMI and waist measurements as part of routine care to assess health risks.

What Is Body Fat and Why It Matters

It is normal and healthy for your body to store some energy as fat. However:

  • Too much body fat can increase your risk of conditions like heart disease, type 2 diabetes, and certain cancers.
  • Too little body fat can lead to malnutrition, weakened immunity, and other health problems.

The location of your body fat matters as much as the amount. Fat stored around your abdomen (belly fat) is more strongly linked to disease than fat stored around your hips and thighs.

In medical settings in Grand Rapids, body fat can be measured accurately with a dual-energy X-ray absorptiometry (DXA) scan, available through major hospital systems. For everyday use, BMI is a practical and low-cost way to estimate body fat and health risk.

BMI: An Approximate Measure of Your Best Weight for Health

How BMI Is Calculated

BMI is calculated using your height and weight:

  • Formula (metric):
    BMI = weight (kg) ÷ [height (m)]²
  • Formula (US units):
    BMI = [weight (lb) ÷ height (in)²] × 703

You can use many online BMI calculators, including tools from local health systems like Corewell Health or national resources such as the CDC.

BMI Categories for Adults

For adults who have stopped growing, the World Health Organization (WHO) defines BMI categories as:

  • Underweight: BMI under 18.5 kg/m²
  • Healthy weight: BMI 18.5–24.9 kg/m²
  • Overweight: BMI 25.0–29.9 kg/m²
  • Obese: BMI 30.0 kg/m² or higher

For most adults, an increase in BMI is usually due to an increase in body fat.

In older adults (around age 70 and above), overall health, strength, and function may be more important than being strictly within the “healthy” BMI range. Some research suggests a BMI of about 22–26 kg/m² may be reasonable for older adults, but this should be individualized with a healthcare provider.

How BMI Is Used in Grand Rapids Healthcare

On a population level, BMI is used to:

  • Estimate the risk of disease (morbidity)
  • Estimate the risk of death (mortality)
  • Track obesity trends in communities, including Kent County and the Grand Rapids metro area

Local organizations like the Kent County Health Department and Grand Rapids Public Health may use BMI data to plan community programs focusing on healthy eating, physical activity, and chronic disease prevention.

Why BMI Is Not Always the Best Measure of Health

BMI is a helpful screening tool, but it has important limitations:

BMI Cannot Distinguish Fat from Muscle

  • Bodybuilders and athletes with a lot of muscle may have a high BMI but low body fat. They are not necessarily overweight or unhealthy.
  • People with physical disabilities who cannot walk may have muscle wasting. Their BMI may be lower, but this does not always mean they are underweight.

BMI and Height

BMI is not entirely independent of height:

  • It may overestimate obesity in very short adults (under 150 cm / about 4'11").
  • It may underestimate obesity in very tall adults (over 190 cm / about 6'3").

In these situations, BMI should be interpreted carefully.

BMI and Ethnicity

Different ethnic groups can have different health risks at the same BMI:

  • Asian and South Asian populations often have more body fat at a given BMI compared with people of European descent.
    • Health risks like type 2 diabetes and cardiovascular disease can start at a BMI as low as 23 kg/m².
  • Some groups (for example, certain Pacific Islander populations) may have similar risks at a higher BMI.

In a diverse city like Grand Rapids, it’s important that BMI is interpreted in the context of your ethnic background, lifestyle, and other risk factors. Local clinicians at Spectrum Health, Trinity Health Grand Rapids, Metro Health, and Mercy Health are trained to consider these differences.

Who Should Be Cautious Using BMI Alone?

BMI is not a fully accurate indicator for:

  • Bodybuilders and some high-performance athletes
  • People with eating disorders (such as anorexia nervosa)
  • People with extreme obesity (additional measures are needed)
  • Older adults with significant muscle loss
  • People with significant physical disabilities

If you fall into one of these groups, consider meeting with a registered dietitian or your Grand Rapids primary care provider for a more complete assessment.

BMI and Children in Grand Rapids

Why Adult BMI Cutoffs Don’t Work for Kids

Children and teens are constantly growing, so adult BMI ranges are not appropriate. For young people, BMI must be interpreted using age- and sex-specific growth charts.

How BMI Is Used in Children

For children and adolescents (ages 2–19), BMI is compared to percentile charts developed by the U.S. Centers for Disease Control and Prevention (CDC). These charts show how a child’s BMI compares with other children of the same age and sex.

BMI for children is usually described as:

  • Underweight: BMI < 5th percentile
  • Healthy weight: 5th to < 85th percentile
  • Overweight: 85th to < 95th percentile
  • Obese: ≥ 95th percentile

In Grand Rapids, pediatricians, school-based health centers, and maternal and child health nurses use these charts to:

  • Identify children at risk for overweight, obesity, or undernutrition
  • Recommend small lifestyle changes (like more physical activity or healthier snacks)
  • Decide when to refer families to a dietitian or pediatric specialist

BMI charts for children are guides, not diagnoses. If you are concerned about your child’s weight, talk to your child’s doctor or a pediatric clinic at a local system such as Corewell Health or Metro Health.

Health Risks of High BMI (Overweight and Obesity)

Being overweight or obese does not guarantee you will become ill, but it raises your risk of many health problems. Research shows:

  • As BMI rises from 25 to 27 kg/m², the risk of death increases by 20–30%.
  • At higher BMIs, the risk can rise even more sharply.

If you are overweight (BMI over 25 kg/m²) and physically inactive, you have a higher risk of:

  • Cardiovascular disease (heart disease and stroke)
  • High blood pressure (hypertension)
  • High cholesterol
  • Type 2 diabetes (a major concern in Michigan)
  • Gallbladder disease
  • Osteoarthritis (joint wear and tear, especially in knees and hips)
  • Certain cancers, such as colon and breast cancer
  • Depression and other mental health disorders

Cold, snowy winters in Grand Rapids can make it harder to stay active outdoors, which may contribute to weight gain and higher BMI if indoor activity is limited. Local gyms, community centers, and indoor walking tracks (such as those offered at some hospital wellness centers) can help residents stay active year-round.

Health Risks of Low BMI (Underweight)

If your BMI is less than 18.5 kg/m², you may be underweight and at risk of:

  • Malnutrition
  • Weakened immune function
  • Higher risk of respiratory infections
  • Digestive diseases
  • Certain types of cancer
  • Osteoporosis (weak, fragile bones)

Underweight can be as serious as overweight. If you are underweight or losing weight without trying, contact your Grand Rapids primary care provider or a registered dietitian for evaluation.

Waist Circumference: A Better Predictor of Disease Risk

While BMI estimates total body fat, waist circumference is often a better predictor of disease risk because it reflects abdominal (belly) fat, also called abdominal obesity.

Why Belly Fat Is Risky

Having a “pot belly” or carrying most of your weight around the middle increases your risk of:

  • Type 2 diabetes
  • High blood pressure
  • High cholesterol
  • Cardiovascular disease (heart attack, stroke)

Fat around the hips and buttocks does not appear to carry the same level of risk.

Men, in particular, tend to gain weight around the waist, which increases their risk of obesity-related diseases. Studies have shown that people with more abdominal fat have higher rates of:

  • Diabetes
  • Hypertension
  • Heart disease

Waist Circumference and Health Risk

For adults, waist circumference can help identify risk for chronic diseases:

For men:

  • 94 cm (about 37 inches) or more: Increased risk
  • 102 cm (about 40 inches) or more: Substantially increased risk

For women:

  • 80 cm (about 31.5 inches) or more: Increased risk
  • 88 cm (about 35 inches) or more: Substantially increased risk

Combined BMI and Waist Risk Levels

When combining BMI with waist circumference, the general pattern is:

  • Least risk: Slim, with evenly distributed body fat
  • Moderate risk: Overweight, but no pot belly
  • Moderate to high risk: Slim, but with a pot belly
  • High risk: Overweight or obese with excess belly fat

Even if your BMI is in the “healthy” range, a large waist circumference can still put you at higher risk.

Genetics, Lifestyle, and Abdominal Obesity

Your tendency to store fat around your middle is influenced by genetics, but lifestyle still plays a major role. You can lower your risk of abdominal obesity and related diseases by:

  • Being physically active (indoor options are important during Grand Rapids winters)
  • Avoiding smoking
  • Eating more unsaturated fats (olive oil, nuts, fish) instead of saturated fats (fatty meats, full-fat dairy)
  • Limiting sugary drinks and highly processed foods
  • Getting regular check-ups and screenings

Local wellness and nutrition programs offered by Corewell Health, Trinity Health Grand Rapids, Metro Health, and the Kent County Health Department can support these lifestyle changes.

About Abdominal Obesity

Abdominal obesity refers to excess fat stored around your waist and internal organs. It is strongly associated with:

  • Insulin resistance and type 2 diabetes
  • High blood pressure
  • Abnormal cholesterol levels
  • Non-alcoholic fatty liver disease
  • Increased risk of heart attack and stroke

In Michigan and the Great Lakes region, where rates of obesity and diabetes are higher than national averages in some communities, addressing abdominal obesity is a key public health priority.

Taking Action in Grand Rapids

If you are concerned about your BMI, waist circumference, or overall weight-related health risks, local resources can help.

Where to Get Help

  • Your Grand Rapids GP / primary care provider
    For BMI assessment, physical exams, lab tests, and personalized advice.
  • Maternal and child health nurses
    For support with infant, child, and family nutrition and growth.
  • Registered dietitians and nutritionists
    Available through:
    • Corewell Health (Spectrum Health)
    • Trinity Health Grand Rapids
    • Metro Health – University of Michigan Health
    • Mercy Health and affiliated clinics
  • Kent County Health Department & Grand Rapids Public Health programs
    For community nutrition classes, weight management support, and physical activity programs.
  • Behavioral health providers
    For support with emotional eating, depression, anxiety, or eating disorders.

Key Points About BMI and Health in Grand Rapids

  • The distribution of body fat (especially around your waist) is more important than total fat when assessing disease risk.
  • Waist circumference is often a better predictor of health risk than BMI alone.
  • Increased abdominal obesity is linked to a higher risk of cardiovascular disease, type 2 diabetes, and certain cancers.
  • In adults who have stopped growing, an increase in BMI is usually caused by an increase in body fat.
  • At the population level, BMI is used to estimate risk of disease and death and to guide public health efforts in communities like Grand Rapids.
  • Because of cold winters and seasonal lifestyle changes in West Michigan, paying attention to BMI, waist circumference, and year-round physical activity is especially important for long-term health.

If you are unsure how to interpret your BMI or waist measurement, schedule an appointment with a local healthcare provider in Grand Rapids to discuss your results and next steps.