How the Body Mass Index (BMI) Affects You

How the Body Mass Index (BMI) Affects You

How the BMI Affects You – Photo by Jason Briscoe on Unsplash

  Written by: Sabrina Sourjah
Date Updated: 4/22/2021
Reviewed by: Patrick D. Randolph, Ph.D.

You may have heard of the Body Mass Index (BMI) during visits to your primary care physician, in weight watchers programs, or in health-conscious communities.

But what exactly is this BMI, and how can it help us?

The BMI measures the body fat of an adult based on one’s height and weight. It’s primarily used to categorize individuals as obese or not.

Why Is the BMI Important?

The obesity rate among American adults was 42.4% in 2020. The national obesity rate has increased by 26% since 2008. Experts consider this as evidence of the impending obesity crisis.

The national medical cost of obesity was $147 billion in 2008. On average, an obese individual spent $1,429 more than someone with a healthy BMI.

BMI Equation

The BMI is calculated by dividing an individual’s weight (in kilograms) by the square of their height (in meters).

You can use this calculator to calculate your BMI. The next step is to check where you fall on the BMI scale.

What BMI Should You Be?

For adults 20 and older, a healthy weight corresponds to a BMI between 18.5 and 24.9. A BMI between 25 and 29.9 denotes an individual who is overweight but not obese. An obese individual will have a BMI between 30 and 40, and a BMI above 40 is a sign of extreme obesity.

How a High BMI Affects You

1. Overall Health

As your BMI rises, it indicates that your body has more fat than required. Because the BMI takes height and age into account, it represents how much fat is healthy for you.

In addition to the BMI’s connection with obesity, it also has a link to heart disease, stroke, diabetes, gallbladder disease, high cholesterol, hypertension, sleep apnea, body pain, and bone and joint problems. A high BMI can also point to cancers like breast cancer, colon cancer, and endometrial cancer.

2. Surgery Outcomes

A study on gastroenterological surgeries found that obesity can lengthen the operative time and increase the risk of short-term post-surgery complications. However, no long-term impact was seen in this study.

For patients with esophageal carcinoma (EC), a high BMI can result in “several surgical complications.” But the risk of postoperative mortality is the same as EC patients with low BMI’s.

3. Mental Health

Obesity has been linked to a 25% increase in the chances of having mood-related disorders and anxiety. Another study also found a connection between obesity and mental illnesses such as depression and bipolar disorder.

When your BMI is high, certain everyday tasks take longer and become more challenging because you have to expend more energy to move. This may keep you from partaking in social activities and hobbies, reducing balance and avenues of stress reduction.

Additionally, obesity can also make one lose their self-esteem because our glossy media generally celebrates model-like figures as the aspiration for all.

4. Longevity

Empirical studies show that every one-unit increase in the BMI can result in a 12% probability reduction of an individual’s healthy survival. For example, obese women’s chance of survival beyond 70 years is 70% lower when compared with lean women with low BMI’s.

5. Life Satisfaction

A BMI vs. life satisfaction study in 27 post-communist countries showed a strong inverse correlation between BMI and life satisfaction. A higher BMI corresponded to lower life satisfaction. However, when economic and political conditions improved, the positive impact of a lower BMI was not as strong.

Another study on a cross-sectional sample of Iranians uncovered a “strong association between the BMI and life satisfaction.” Other factors contributing to life satisfaction were Health-Related Quality of Life (HRQoL) and the existence of chronic diseases.


A high BMI can impact almost all aspects of your life. Tracking the BMI and maintaining it within the healthy range is vital to our well-being.