Over 75% of US adults may meet criteria for obesity under new definition

Key Concepts

• Body Mass Index (BMI): A calculation using height and weight to estimate body fat.
• Waist Circumference: Measurement around the waist, used as an indicator of abdominal fat.
• Obesity: Defined traditionally by BMI, now being re-evaluated with inclusion of waist circumference measurements.
• Lancet Global Commission: The organization proposing the new obesity definition.
• Chronic Disease: Long-lasting health conditions, often driven by obesity (e.g., cardiovascular disease, diabetes).
• Weight Loss Medications: Pharmaceutical interventions designed to aid in weight reduction.

New Obesity Definition and US Health

The video discusses a new definition of obesity proposed by the Lancet Global Commission, which incorporates both Body Mass Index (BMI) and waist circumference measurements. Traditionally, obesity has been primarily assessed using BMI – a calculation based on height and weight. However, researchers now argue that BMI alone significantly underestimates obesity prevalence in the US because it doesn’t account for fat distribution. Specifically, abdominal fat (measured by waist circumference) is considered more detrimental to health than fat in other areas of the body.

According to new estimates utilizing this revised definition, over 75% of adults in the US may meet the criteria for obesity. This figure is significantly higher than estimates based solely on BMI. Dr. Dmitri Dascalakis, a former top CDC official, explains that “not all fat is built the same,” emphasizing the clinical significance of abdominal fat.

This high prevalence, Dr. Dascalakis states, “reaffirms what we all know, which is that obesity is a big problem in the US and drives a lot of cardiovascular and endocrine disease like diabetes.” He notes that obesity is “probably…one of the most significant drivers of chronic disease.”

Research Methodology and Further Investigation

The estimates are based on analysis of data from the National Health and Nutrition Examination Survey (NHANES) using the new criteria. Dr. Dascalakis cautions that further research is needed, specifically regarding potential stratifications based on age and other factors. He emphasizes the need for a “deeper look” into the implications of this new definition.

The study period also predated the widespread popularity of recent weight loss medications, meaning the data doesn’t fully reflect the impact of these treatments. A key question raised is how this new definition will affect eligibility criteria for these medications. “If you do use this new definition, how does that change people's…qualifi[cation] or not for the use of these…weight loss drugs?” Dr. Dascalakis asks.

Weight Loss Medications and the Broader Context

The video acknowledges the recent success and popularity of weight loss medications. However, the study’s findings, using the new obesity definition, suggest that despite these advancements, obesity remains a substantial problem. The new definition aims to align US obesity assessment with practices in other parts of the world that already consider waist circumference alongside BMI.

Recommendations for Individuals

As the New Year approaches, Dr. Dascalakis recommends a combination of exercise, diet, and close collaboration with a healthcare provider. He suggests that individuals consult with their doctors to determine if they qualify for weight loss medications as part of their weight loss journey.

As Dr. Dascalakis succinctly states, “the bottom line is that we know that the US has an obesity problem. This just affirms that.”