Being a couch potato in your younger years is directly related to childhood obesity, but a new study shows that light exercise may totally undo this chronic disease.

The study was completed as a collaboration between University of Exeter, University of Eastern Finland, University of Bristol, and University of Colorado and recently published in Nature Communications.

The research is one of the biggest and longest follow-up studies to monitor physical activity and fat mass. It utilized the University of Bristol's Children of the 90s data (also known as the Avon Longitudinal Study of Parents and Children. Over 6,050 children (53% girls) aged 11 years that were monitored until they turned 24.

Recent studies suggest that over 80% of teenagers globally don’t meet the World Health Organizations’ (WHO) advised average of one hour per day of moderate to vigorous physical activity.

It’s predicted that being sedentary will have caused 500 million new cases of diabetes, heart disease, obesity or other noncommunicable chronic disease by 2030 which annually costs 21 million.

This scary statistic regarding sedentary lifestyle requires urgent research on the most effective prevention.

However, results of this recent study find that moderate-to-vigorous exercise is up to ten times less effective than light physical activity in reducing overall fat mass gain.

According Dr Andrew Agbaje of the University of Exeter led the study, "These new findings strongly emphasize that light physical activity may be an unsung hero in preventing fat mass obesity from early life. It is about time the world replaced the mantra of 'an average of 60 minutes a day of moderate-to-vigorous physical activity' with 'at least 3 hours a day of light physical activity'. Light physical activity appears to be the antidote to the catastrophic effect of sedentary time in the young population."

Throughout the study, an accelerometer worn on the waist measured sedentary time, light physical activity, and moderate-to-vigorous physical activity among subjects at ages 11, 15, and 24 years.

Dual-energy X-ray absorptiometry-measured fat mass and skeletal muscle mass were also collected at the same ages. Fasting blood samples were repeatedly measured for glucose, insulin, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, and high-sensitivity C-reactive protein.

Blood pressure, heart rate, smoking status, socio-economic status, and family history of heart disease were measured and controlled for in the analyses as well.

Over the 13-year follow-up, sedentary time increased from roughly six hours a day in childhood to nine hours a day in early adulthood.

Moderate-to-vigorous physical activity was fairly stable at 50 minutes per day from childhood to young adulthood while light exercise decreased from six hours per day to three hours daily.

For each minute spent being sedentary, a 1.3 gram increase in total body fat mass was observed. Male and female children both picked up an average of 10 kg of fat mass through growth from childhood to early adulthood.

Yet, sedentary time possibly added 700 grams to 1 kg of fat mass (roughly seven to ten percent) of the total fat mass picked up throughout growth from childhood to early adulthood.

A 1 kg gain in fat has been linked with a 60% higher risk of premature death in individuals in their early 50’s. Just one minute spent doing light physical activity during growth from childhood to early adulthood was linked with a 3.6 gram reduction in total body fat mass.

This suggests that cumulative light physical exercise lowered total body fat mass by 950 grams to 1.5 kg throughout growth from childhood to young adulthood (roughly 9.5 to 15 percent drop if overall fat mass gain throughout the 13-year observation period).

Long walks, household chores, dancing slowly, slow swimming and slow biking are examples of light physical activity.

By comparison, completing the WHO’s recommendation of 60 minutes per day of moderate-to-vigorous physical activity during childhood growth to young adulthood was linked with 70 to 170 grams (roughly .7 to 1.7 percent) drop in total body fat.

Before this study, quantifying the long-term impact of sedentary time to fat mass obesity and the impact of how physical activity may reduce it has not been possible. This research confirmed the analysis from a recent meta-analysis of 140 school-based randomized control trails across the globe that doing moderate-to-vigorous exercise had limited or no impact on reducing childhood obesity.

According to Dr Andrew Agbaje of the University of Exeter, "Our study provides novel information that would be useful in updating future health guidelines and policy statements. Public health experts, health policymakers, health journalists and bloggers, pediatricians, and parents should encourage continued and sustained participation in light physical activity to prevent childhood obesity."

Here are some tips to increase physical activity in children throughout their lifespan:

·         Be a role model. Limit your screen time and participate in walking, jogging, or other light activity

·         Take a tumbling class with your toddler

·         Schedule play time with family. Kick a ball in your yard or go for a family hike.

·         Limit your children’s screen time. Using a screen or watching TV often are sedentary behaviors.

·         Find a family-friendly gym or recreation center in your neighborhood.

·         Encourage children to join a sports team or league so they have regular physical activity built in.

·         Go for a family bike ride when the weather is nice.

·         Join a neighborhood pool in the summer.

·         Use a DVD or YouTube video for indoor exercise in colder months

·         Praise children for being active, but don’t reward them with food.

Lisa Andrews, MEd, RD, LD

Reference:

1.    Andrew O. Agbaje, Wei Perng, Tomi-Pekka Tuomainen. Effects of accelerometer-based sedentary time and physical activity on DEXA-measured fat mass in 6059 children. Nature Communications, 2023; 14 (1) DOI: 10.1038/s41467-023-43316-w