Relationship between summer vacation weight gain and lack of success in a pediatric weight control program.

The purpose was to measure the effect of holidays or season on changes in body weight to determine if this was the reason for the low success rate of weight control program participants. Changes in percent ideal body weight were gathered on 73 overweight youth (average age: 10.5+/-2.8 years; percent ideal body weight: 150+/-28%) over 2-month intervals in a 1-year time span. There was a statistically significant gain in percentage of body weight during July-August compared to January-February at p<0.004, March-April at p<0.04, May-June at p<0.001 and September-October at p<0.04. Sixty-six percent of subjects gained weight during the summer months. When the subjects who lost weight in the summer period were removed from the analysis, the average weight gain was 2.8% of ideal body weight. For a weight control program for children and adolescents to be effective, strategies need to be developed to deal with the summer vacation period as this can affect the overall success in the program.