Field Notes

Body Composition Affects Energy Spent Standing vs Sitting

A person’s body composition could influence the difference between the amount of energy they spend while sitting vs standing, according to new research published in the open-access journal PLOS One. Conducted by Francisco J. Amaro-Gahete, a doctoral student at the University of Granada, Spain, and colleagues, this work adds to mounting evidence that more energy is expended while standing than while sitting or lying down.

Sedentary lifestyles are linked to increased risk of a variety of health conditions, including diabetes, obesity, and cancer. The difference in energy a person expends while standing vs sitting or lying down may be a key factor influencing health risks, but previous studies have found conflicting results about the actual size of these differences. Also, body composition could impact these differences, but its role has been unclear.

To address these issues, Amaro-Gahete and colleagues measured energy expenditure differences between lying, sitting, and standing for 55 young adults aged 18 to 25. In line with previous research, the participants burned significantly more kcal per minute while standing than while sitting or lying, while no difference was seen for sitting vs lying.

Notably, the researchers also examined associations between energy expenditure in different positions and body composition of the participants. They found no significant associations when comparing energy spent lying vs sitting or lying vs standing. However, they did find that participants with a higher lean body mass had a smaller difference in energy spent sitting vs standing.

These findings lend new support to the idea that a simple way for a person to increase their energy expenditure is by increasing their time spent standing. The results could also aid efforts to better understand, monitor, and counteract sedentary lifestyles.

Amaro-Gahete adds, “Increasing the time spent standing could be a simple strategy to increase energy expenditure.”

— Source: PLOS


One-Half of Kids Have Ideal Cholesterol Levels

Cholesterol levels in US youth have improved from 1999 to 2016, but only one-half of children and adolescents are in the ideal range and 25% are in the clinically high range, according to a study published in JAMA led by Amanda Marma Perak, MD, MS, a cardiologist at Ann & Robert H. Lurie Children’s Hospital of Chicago. The study is the first to report estimated prevalence of high cholesterol in youth in recent years, analyzing nationally representative data from more than 26,000 children and adolescents (aged 6–19).

“High cholesterol in childhood is one of the key risk factors for developing heart disease later in life,” says Marma Perak, who is also an assistant professor of pediatric cardiology and preventive medicine at Northwestern University Feinberg School of Medicine. “Although we see favorable trends in all measures of cholesterol in children and adolescents over the years, we still need to work harder to ensure that many more kids have healthy cholesterol levels. We know that high cholesterol is the critical initiator of atherosclerotic plaques in the arteries, and even in childhood it is associated with these changes in the blood vessels that can lead to heart attack in adulthood.”

For children and adolescents, ideal measures include total cholesterol at less than 170 mg/dL, LDL at less than 110 mg/dL, and HDL at greater than 45 mg/dL. These levels are associated with better long-term health. All youth should have their cholesterol checked at ages 9–11 and again at 17–21, according to the latest guidelines from the National Heart, Lung, and Blood Institute.

“If a child is found to have borderline-high or high levels of cholesterol, we can usually improve those levels through lifestyle changes, such as healthier diet and increased physical activity,” Marma Perak says. “Children are rarely placed on cholesterol-lowering medications like statins.”

The improving cholesterol trends observed in the study are surprising given that obesity is one of the factors that drives abnormal cholesterol levels, and childhood obesity continues to increase.

“More research is needed to understand the reasons for the favorable cholesterol trends we found,” Marma Perak says. “Some factors that influence cholesterol may be improving, such as decreased trans fats in the food supply. Although more efforts are needed, the fact that cholesterol levels are moving in the right direction warrants some optimism about the future cardiovascular health of our population, since cholesterol is such an important driver of cardiovascular disease.”

— Source: Ann & Robert H. Lurie Children’s Hospital of Chicago