A handful of studies show that school-based programs can help children lose weight, or at least avoid putting it on. Results were presented at the North American Association for the Study of Obesity’s (NAASO) Annual Scientific Meeting this week in Las Vegas.

In the first year of a three-year study, a school-based fitness program, the FitKid Project at the Medical College of Georgia, showed that with 80 minutes of physical activity (based on acquiring motor skills through sports and 40 minutes of vigorous exercise with heart rates above 150 beats per minute) and 40 minutes of academic help, including homework help, students can increase their bone density, improve their cardiovascular fitness, have a smaller increase in their waist circumference and decrease their body fat percentage.

Over the course of a school year, third-graders in Augusta-Richmond County who participated in at least 40 percent of the daily, after-school classes saw a 0.7 percent decrease in their body fat, compared to a 0.1 increase in body fat by other kids who did not participate. Those who were there for 80 percent of classes saw a 1.1 percent drop.

Another study presented calculated the potential calorie-saving effect of decreasing middle school snack-bar portion sizes to ‘pre-supersize’ levels. By using sales data from 23 Texas middle school snack bars, researchers found that students could have consumed an average of 45 fewer calories a day if snack bars sold 1-ounce bags of chips instead of 3.75-ounce bags, and 12-ounce cans of sweetened drinks rather than 20-ounce bottles. This simple switch could prevent up to two pounds of excess weight gain per child.

The final study focused on the dreaded “freshman 15” for university students. Researchers in Quebec found that enrolling first-time students in a group seminar about improving and maintaining healthy lifestyles helped them to lose about a half of a pound over a year, while students not in the seminar gained an average of 4 pounds.

Seminars taught students about obesity and its consequences, good food habits, food caloric density concepts, and the benefits of physical activity. It also included information about local fitness centers and tips to maintaining weight through midterms and other stressful times.

The NAASO’s Annual Scientific Meeting is a joint effort with the American Diabetes Association to increase awareness of the rising problem of obesity and its related health problems in the United States, according to a release about the meeting.