Recent research demonstrates that comparing waist circumference to height could provide a more accurate picture than the body mass index (BMI), which has been in use for decades. This method would allow for better identification of where fat is stored, an important factor for cardiovascular health.
This study, published in
The Lancet Regional Health—Americas, shows that current approaches for estimating cardiac danger might overlook many people. Indeed, those not classified as obese according to traditional standards could nevertheless present an increased risk for their heart if their waist circumference is large relative to their height.
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To reach these findings, the scientists examined health data from 2,721 Brazilian adults participating in a longitudinal study. None of these participants suffered from cardiovascular disease at the start of the follow-up, which lasted over five years. The objective was to see how certain initial body measurements were linked to the later onset of heart problems.
The results highlighted that the waist-to-height ratio remained a significant predictor even after accounting for other factors like age or smoking. In contrast, the association between BMI and cardiac risk became less clear once these elements were considered. This underscores the particular interest of this measurement for individuals whose BMI is below 30, the usual threshold for obesity.
The advantage of the waist-to-height ratio lies in its ability to reflect abdominal obesity, linked to visceral fat. Unlike BMI, which does not distinguish between types of fat, this simple measure directly captures the distribution of fat reserves around internal organs. Thus, a person with a normal BMI but a high ratio could see their risk of developing coronary artery calcification increase.
The study's authors, such as Thiago Bosco Mendes, observed that this ratio could serve as a practical screening tool. Marcio Bittencourt, a cardiologist, added that it allows for early identification of at-risk patients, even when their weight, cholesterol, and blood pressure appear normal. This simplified approach could therefore complement classical assessments.
Implementing this measure in routine medical practice could help detect warning signs earlier. It is an accessible avenue for improving the prevention of cardiovascular diseases, particularly for individuals with conventionally acceptable weight. Its calculation requires only a tape measure and knowledge of one's own height.
The waist-to-height ratio: how does it work?
The waist-to-height ratio, often abbreviated WHtR, is obtained by dividing your waist circumference (in centimeters or inches) by your height (in the same unit). For example, if your waist is 31.5 inches (80 cm) and you are 63 inches (160 cm) tall, the ratio is 0.5. This figure allows you to judge the proportion of fat accumulated around the abdomen relative to your overall stature.
A value greater than 0.5 is generally considered a warning signal for cardiovascular health. This means that abdominal fat is significant, even if your total weight seems normal. This threshold is easy to remember and apply, making this measurement practical for regular self-checking at home.
Unlike BMI, which only considers weight and height, WHtR incorporates the location of fat reserves. It is therefore more specific for assessing the risk related to central obesity. Many studies have shown that a high ratio is associated with a greater danger of developing problems like diabetes or hypertension.
To calculate your own ratio, use a soft tape measure and measure your waist at the level of the navel, without tightening. Note this value and your height in centimeters or inches, then perform the division. Interpreting the result with a healthcare professional can help adapt your lifestyle if necessary.
Abdominal fat and its effects on the body
The fat that accumulates around the waist is not just simple energy storage. It consists mainly of visceral fat, located inside the abdomen, around organs like the liver, pancreas, and intestines. This type of fat is metabolically active and can release substances that influence the body's functioning.
Unlike subcutaneous fat, found just under the skin and which is less harmful, visceral fat is associated with chronic low-grade inflammation. This inflammation can disrupt the regulation of blood sugar and blood pressure, thereby increasing the risk of cardiovascular diseases and insulin resistance.
The presence of excess visceral fat is also linked to changes in the lipid profile, with an increase in bad cholesterol (LDL) and a decrease in good cholesterol (HDL). These changes contribute to the formation of plaques in the arteries, a process that can lead to heart attacks or strokes over time.
Measuring waist circumference allows for an indirect estimation of this visceral fat, as a high circumference is often its reflection. Adopting habits like a balanced diet and regular physical activity can help reduce this abdominal fat, thus improving overall health without necessarily focusing on total weight loss.