BMI, or body mass index, has been one of the most popular measurements for weight management. This helps to assess a person’s body fat percentage in relation to their weight and height. The higher the BMI, the greater the risk of heart disease and type 2 diabetes.

However, a new study found that BMI has its own challenges as the only way to obesity.

The study presented in European Congress on European Congress (Eco 2025) in Malaga, Spain, run by experts from Italy and Lebanon, suggests that as people are of age, their body composition changes a lot, even if their BMI is equal.

BMI alone cannot tell the full story

BMI is widely used to classify individuals as normal weight, overweight or obesity. However, the study found that people with similar BMIs may have very different fat and muscle distribution depending on their age.

Researchers noticed that as people are of age, fat accumulates in the middle areas of the body, while muscles and legs decrease in muscles.

One of the authors of the study of Modena University and Razigio Emilia, Professor Marwan L. Ghoch said that these changes make BMI a less reliable equipment. “We cannot only rely on BMI, without considering how the body fat and muscles are distributed,” he explained.

Conclusion from study

The study analyzed 2,844 adults aged 20 to 79, with all 25 or more BMI. Participants were divided into three groups: Yuva-Ayu (20–39 years), middle age (40–59 years), and old-age (60–79 years).

Their body compositions were measured using dual-energy X-ray absestiometry (DXA), a technique that provides detailed analysis of fat and muscle distribution.

Major findings include:

• Men increased the total body fat and decreased muscles as they agreed.
• Women had relatively total body fat and mass mass in various age groups.
• Middle -aged and older adults had less adult mass in the abdomen and stomach (from 1.23% to 4.21%) and their arms and legs less muscles (from 0.81 kg to 2.63 kg) less adult mass than less adults.

These changes in the body structure can have serious health consequences, including:

• The risk of insulin resistance and cardiometabolic diseases increased
• High level of chronic inflammation
• Low muscle strength and mobility

Professor El Ghoch has warned that fully relying on BMI can be misleading. He said, “Obesity related risks can be underestimated if we do not eat for fat distribution and muscle damage,” he said.

Given these findings, researchers suggest transfer to alternative methods to assess the structure of the body. Professor L. Ghoche recommends the equipment:

• Back-to-back ratio
• Handgrip strength test to measure muscle and strength

While more research is required to confirm these findings, the study highlights the importance of moving from BMI to obtain a clear picture of obesity and its risks.