Obese Children & Very Low Calorie Diet, Exercise, And Behavior Modification - Brief Article

Nutrition Research Newsletter, Jan, 2001

Programs to treat obesity in childhood are not commonly available, and when available, are usually unsuccessful in maintaining weight loss. This lack of success may be due to the fact that lifestyles that contribute to the development of obesity are not effectively altered during weight reduction. Because growth velocity may be negatively impacted by a restricted caloric intake, growth velocity must be followed carefully during and after weight loss, especially in children with short stature.

This recently published study describes a structured diet and exercise program, in combination with behavior modification and lifestyle alterations, developed to treat obesity in children. The 1-year program consists of three components: a very low-calorie diet (VLCD) followed by a less restrictive balanced hypocaloric diet (BHD), a moderate-intensity progressive exercise program (MPEP), and behavior modification.

Children between the ages of 7-17 years were evaluated for enrollment into the study. Subjects who met enrollment criteria were entered in one of four cohorts. A new cohort of subjects was started every 3 months. Cohorts 1 through 4 consisted of 11, 18, 11, and 16 subjects, respectively. The mean ages for the four cohorts were 12.9, 10.8, 12.5, and 11.3 years, respectively. Subjects were not enrolled if their weights were [is less than] 130% ideal body weight (IBW). Subjects were classified as mildly obese (130-149% IBW), moderately obese (150-199% IBW) or severely obese ([is greater than or equal to] 200% IBW). The 1-year program began with an intensive 10-20 week intervention period that focused on acute weight loss. The VLCD consisted of 1.5-2.0 g protein/kg IBW/d and supplied approximately 800 kcal/d. The prescribed protein accounted for [is less than] 50% of the total calories, and consisted of lean meat, fish, or chicken. To induce ketosis, carbohydrate was limited to a maximum of 20-25g/day. Fat from lean protein sources contributed [is less than] 40g lipid/d. All subjects were supplemented with a daily multivitamin, calcium carbonate, potassium chloride and subjects were encouraged to drink at least 2 liters of water each day. Subjects checked their urine for ketones each morning.

The moderate-intensity exercise program included aerobics, as well as strength and flexibility exercises. The exercise program was specific to the class of obesity. Aerobic activity was performed at home and was selected from an extensive list of activities. Each child kept an exercise report card. At least one parent attended each weekly session as part of the behavior modification component. Family behavior modification consisted of both individual and group sessions.

Fifty-two of the original 56 subjects completed the weight reduction phase, and 35 of the 52 subjects completed the 1-year program. The mean attendance for all cohorts was 91% during the acute intervention phase, and 57% during the weight maintenance phase. Sixteen patients who reached a goal of [is less than or equal to] 120% IBW did not complete the entire program. There was a significant average weight loss of 9.4 kg during the weight reduction phase. The average height increased significantly during the weight reduction phase as well. The mean % IBW decreased significantly as well, from 176.2 [ or -] 33.9% to 150.6 [ or -] 30.4%. At the end of the 1-year period, the average BMI for the entire group (n=35) was 28.8 [ or -] 5.7. Prior to the VLDC, the mean BMI was 32.7 [ or -] 7.0, and after the VLCD mean BMI was 28.4 [ or -] 6.6. The reduction in BMI during the 1-year period was statistically significant.

The linear growth and growth velocity data in this study suggest that most male and female subjects are able to sustain growth at a normal rate for their chronological age, height age, or both. A program of this nature should be carefully monitored by a physician because the safety of VLCDs in obese children enrolled in an outpatient program is still under investigation. Medical professionals should only prescribe VLCDs in patients with severe obesity or other serious medical concerns that require weight loss. The use of VLCDs in patients with short stature should be delayed until they reach their full growth potential unless the excess weight presents a life-threatening situation.

M. Sothern, J. Udall, R. Suskind, A. Vargas, U. Blecke, Weight loss and growth velocity in obese children after very low calorie diet, exercise, and behavior modification. Acta Paediatr 89:1036-1043 (2000) [Correspondence: U Blecker, Division of Gastroenterology and Nutrition, Alfred I. DuPont Hospital for Children, 1600 Rockland Rd., Wilmington, DE 19803. E-mail: ublecker@nemours.org].