According to the Centers for Disease Control and Prevention, 25 percent of Americans have inactive lifestyles (they take fewer than 5,000 steps a day) and 75 percent do not meet the weekly exercise recommendations (150 minutes of moderate activity each week and muscle-strengthening activity twice a week) to maintain good health. After reviewing recent literature, University of Missouri researchers contend that physical inactivity is the primary cause of chronic diseases such as diabetes, obesity and fatty liver disease and that even people who set aside time for exercise regularly but are otherwise sedentary, may not be active enough to combat these diseases. Inactivity, in addition to the availability of high-caloric food has led to an increased rate of metabolic dysfunction in Americans.

In a recent study, John Thyfault, assistant professor in the departments of Nutrition and Exercise Physiology and Internal Medicine, found that negative physiological changes associated with a higher risk for type 2 diabetes, occur in people who transition from high amounts of activity (greater than 10,000 steps a day) to inactivity (fewer than 5,000 steps each day).

"If people spend the majority of their time sitting, even with regular periods of exercise, they are still at greater risk for chronic diseases," Thyfault said. "If people can add some regular movement into their routines throughout the day, they will feel better and be less susceptible to health problems. In the long term, they may not see big changes in the mirror, but they will prevent further weight gain."

According to Scott Rector, assistant professor in the departments of Nutrition and Exercise Physiology and Internal Medicine, nonalcoholic fatty liver disease (NAFLD) is a relatively new epidemic related to the recent increase in obesity and physical inactivity rates. The disease, which is the most common chronic liver condition among U.S. adults, occurs when excess fat accumulates in the liver. This change disrupts glucose regulation and contributes to insulin resistance and type 2 diabetes. NAFLD progresses more rapidly in young people than in adults and has become more common in children.

"Everyone should try to take at least 10,000 steps a day," Rector said. "It doesn't have to happen all at once, but 500 to 1,000 steps every few hours is a good goal. Small changes can increase the number of steps people take in their daily routines. Changes might include taking the stairs instead of the elevator, walking to a coworker's office rather than calling, or planning time for short walks throughout the day."

Rector said research shows that more active kids are less likely to have fatty liver disease. If doctors and parents intervene and compel children to exercise and lose weight, it will lower their body fat and provide long-term health benefits if they sustain those lifestyle changes.

Thyfault is researching inactivity as it relates to type 2 diabetes and obesity. Rector is examining the relationship between inactivity and NAFLD. Their review articles will be published in the Journal of Applied Physiology. The Department of Nutrition and Exercise Physiology is jointly administered by MU's College of Agriculture, Food and Natural Resources, College of Human Environmental Sciences and School of Medicine. Both researchers have joint appointments in the Department of Internal Medicine in the School of Medicine.