The Impact of Nutrition on the Autonomic Nervous System

Autonomic imbalance measured by 24 hour HRV (heart rate variability) analysis is described for overweight children as well as for patients with anorexia nervosa. Autonomic imbalance is a predictor of possible metabolic syndrome, cardiovascular disease and impaired neurodevelopment. In our cross-sectional study we compared HRV parameters for a healthy control group and constitutional thinness with patients with anorexia nervosa and overweight children. We had found that, children with anorexia nervosa had had significantly lower heart rates at night whilst in overweight children significantly higher heart rates. Concomitant anorexia nervosa patients - children with constitutional thinness and the same body mass index (BMI) had a significantly higher SDNN (standard deviation of all RR-intervals) while overweight children had a significantly lower SDNN. Within all groups we had found a strong and significant correlation between SDNN and heart rate at night. The obesity education program KIDS and the in hospital refeeding in anorexia nervosa patients significantly improved heart rate variability. Chi square test show a highly significant interrelationship between changes in BMI and changes in 24 hour heart rate. Micro nutrition and the role of omega- 3-fatty supplementation was measured and discussed. Our data were compared with data of undernourished and stunted children from the literature. We concluded that not current BMI but rather metabolic rate predominantly determines intrinsic heart rate. We propose a comprehensive model to explain the impact of nutrition on the autonomic nervous system and discuss the therapeutic consequences.