How Do We Judge the Health of Weight?
Obesity statistics often take estimates of body fat using body mass index (BMI). Although BMI isn’t perfectly correlated with body fat percentage, it’s a quick and easy method for collecting data using just the person’s height and weight. If the BMI is higher than 25, a person is considered overweight. If it’s above 30, they’re considered obese. But BMI doesn’t tell us how healthy someone is on the inside.If You’re Not Overweight, Does a Healthy Lifestyle Matter?
Many people think if they’re able to stay lean while eating poorly and not exercising, then that’s OK. But though you might appear healthy on the outside, you could have the same health concerns as overweight and obese individuals on the inside.So even if you don’t smoke and you’re not overweight, being inactive and eating poorly increase your risk of developing heart disease.
Unhealthy Diets Are Bad for Your Body, But What About Your Brain?
Recent research has also shown overconsumption of high-fat and high-sugar foods may have negative effects on your brain, causing learning and memory deficits. Studies have found obesity is associated with impairments in cognitive functioning, as assessed by a range of learning and memory tests, such as the ability to remember a list of words previously presented some minutes or hours earlier.Notably, this relationship between body weight and cognitive functioning was present even after controlling for a range of factors including education level and existing medical conditions.
Body weight was not hugely different between the groups eating a healthy diet and those on high fat and sugar diets. So this shows negative consequences of poor dietary intake can occur even when body weight has not noticeably changed. These studies show body weight is not always the best predictor of internal health.
We still don’t know much about the mechanisms through which these high-fat and high-sugar foods impair cognitive functioning over such short periods. One possible mechanism is the changes to blood glucose levels from eating high-fat and high-sugar foods. Fluctuations in blood glucose levels may impair glucose metabolism and insulin signaling in the brain.
Many people use low body weight to excuse unhealthy eating and physical inactivity. But body weight is not the best indicator of internal well-being. A much better indicator is your diet. When it comes to your health, it’s what’s on the inside that counts and you really are what you eat.