Body fat and waist size is a predictor of chronic disease. Centrally located fat distribution is linked to both physical and mental dysfunctions. Both body fat and waist size can be measured at our convenience.
Body fat is superior to the flawed BMI. BMI is an imperfect measurement, and yet it is still useful, at least in a general way. The BMI formula developed in the 19th century by a Belgian statistician and sociologist. Overweight and obesity is an increasingly important health variable which has been shown independently to influence mortality and morbidity in adults and children. The use of BMI as a measure of weight status is widespread. This understandable due to its simplicity, cost and labor effectiveness compared with other body fat assessments.
The validity of BMI is based on the assumption that as BMI increases so does adiposity (fat tissue). However, researchers have begun to question this assumption. Studies are finding that BMI and Body Fat do not follow the same linear track. For example, a thin woman who gains 2.2 lbs. could represent an increase of 2.3% body fat, but for an obese woman only a 0.3% increase in body fat.
This difference is absolute body fat percentage versus BMI would underestimate the thinner woman and overestimate the heavier woman. BMI misrepresents measurements for child and adults, rendering assumptions made about a child’s BMI an invalid projection about that child’s adult BMI status.
Body fat is superior to the flawed BMI
As stated earlier, BMI is not a good diagnostic tool for children. A child may have a high BMI for their age and gender, however determining whether excess fat is a problem requires further assessments (with adults as well). For this reason, a healthy weight range is not possible for most pre-teen and adolescents, as their bodies are changing rapidly throughout these years.
New research shows a normal BMI can hide metabolic abnormalities. Individuals who fit into the “normal” range for height and weight can suffer disorders; scientist understands now that our bodies handle nutrition differently. Researchers have begun documenting the different ways metabolic condition like insulin resistance elevates the risk of heart disease and Alzheimer. One in four people with a “normal” BMI experienced some form of metabolic abnormality, according to a 2008 study.
An elevated BMI does not necessarily equate to poor metabolic health. Fifty percent of all people who are overweight experience zero metabolic abnormalities. In fact, people who are overweight but not obese live longer, than people with normal BMI’s. However, this isn’t the same as saying if you’re overweight all is O’k. Everyone’s body is different, there doesn’t appear to be a one size fits all situation.
There isn’t a universal agreement to define a healthy waist size or guidelines to determine an age specific size. The need for age-specific waist size cannot be known. What is known is both waist size and risk of chronic diseases increase with age.
Waist and Hip Physical Health
Excess fat is a well established risk factor for a variety of chronic diseases and early death. Total fat and fat distribution appear to affect morbidity and mortality. High amounts of visceral body fat measured by waist circumference have been found to be a better predictor of overweight related risk factors than body mass index (BMI). Waist to Hip Ratio has been found to predict health outcomes.
Research has mostly focused on waist circumference as a health predictor due to the accumulation of visceral fat. Waist to Hip ratio could also be ascribed to smaller hip circumference especially in women. Women hip circumference tend to vary more than men over time when adjustments are made for height and weight. Women with smaller hip circumference are associated with increased risk of heart disease, myocardial infarction and diabetes. At this time, no longitudinal studies have examined the effects of chronic diseases over time, as women hip size tend to change with age. Additionally, similar results have not been correlated with men where waist size is a greater health predictor.
Waist and Hip Body Fat
There are substantial differences in body composition in men and women, with women having higher levels of body fat. Fat distribution also differs by gender; men’s fat tend to be centrally located. In both men and women, waist and waist to hip ratio increase with age. Weight gain drives the increases. Waist circumference is seen in aging adult’s absence of weight gain. Younger adult’s waist size increase more than older adults, probably due to greater weight gains during young adulthood. With weight gain, waist size and waist-to-hip ratio increase, but men have larger increases in waist circumference with weight gain than women.
One of the best tools to determine future health outcomes is available to everyone on an ongoing and regular basis. For the price of a simple tape measure, we can regularly check our progress. Of course, this does not eliminate medical or mental health professionals. In an era where patient engagement is high on everyone’s mind, measuring waist and hip circumference is patient centered.
Sense of Smell May make us Fat
New research from the University of California Berkeley discovered that smelling food could turn off our metabolism and signal to the body to store the calories as fat rather than burn them as energy. This research adds to saying once the appetite gets involved in what we are going to eat we lose.
Another study from Stanford University shows that Americans are one of the laziest countries on the planet. The researchers tracked steps taken from 46 nations, what made Americans stand out is the gap between those that walked a lot and those who walked very little. Laziness or inactivity is based on the difference in a country where some people achieved a sizeable amount of activity and others did not. American’s have one of the largest gaps examined. Inactivity is one of the leading causes of obesity.
Overfat better measurement than BMI
Lastly, researchers at Auckland University of Technology in New Zealand has produced what they think is a better way to determine health risk. Obesity and overweightedness are well established culprit of numerous health risk in the U.S. and other developing countries. However, the way in which we determine if a person is overweight or obese may be underestimating the scope of the problem state researchers.
The researchers report that overfat is a better determinant of risk that a simple BMI measurement. Overfat is determined by measuring the circumference around the waist at the navel, then checking if that number is more than half their height. Unfortunately, this measurement would put more of us into the overfat category. This analysis would put between 62% to 76% of the world’s population into the overfat category. In the U.S. that would mean 90% of men and 50% of children would be overfat and 80% of adult women.
This is why BMI is such a flawed measurement in determining risk. A person may have a high BMI while carrying a low level of body fat conversely others may show a healthy weight, but the waist measurement could place them into the overfat category.
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