Impact of COVID-19 lockdown on adolescents in treatment for obesity.

OBJECTIVE: The aim of this study was to evaluate the impact of coronavirus disease 2019 (COVID-19) lockdown on body mass index (BMI) z-score of adolescents treated for obesity, and to assess the correlation between BMI z-score changes and lifestyle variables. METHODS: This cross-sectional study recruited 66 participants aged 11-18 years with overweight or obesity who attended our obesity clinics before and after the lockdown. We assessed demographic and anthropometric characteristics as well as lifestyle variables. RESULTS: The mean BMI z-score of the participants was stable during this period (p = 0.233). Balanced diet, snacking, and sweet beverage consumption improved in about half of the participants. Having at least one parent at home was associated with a significantly more balanced diet (p = 0.008) and an increase in family activities (p = 0.015). Physical activities decreased (51.5%) and screen time increased for most of the adolescents (86.4%). The BMI z-score decreased significantly when three or more lifestyle habits improved (p<0.001). CONCLUSIONS: This study showed that BMI z-scores were stable for a majority of adolescents treated for obesity during the COVID19 lockdown, along with positive and negative changes on weight-related lifestyle habits. This extraordinary period may have created opportunities for lifestyle modification and has emphasized the importance of family support in the management of obesity in adolescents.

Biomass active fraction evaluated by a direct method and respirometric techniques.

The knowledge of the active biomass amount and its characterisation is of primary importance for the management and for the design of wastewater treatment plants on the basis of the recently developed models. OUR curves obtained in aerobic exponential growth tests are proposed by several authors as an indirect method to estimate the active fraction. The aim of this work is the application of a direct method to measure the viable biomass based on flow cytometry techniques and the comparison with the active fraction obtained from respirometric tests. To assess the viable fraction of a biomass expressed in terms of COD concentration it is necessary to estimate the biovolume of viable bacteria and to know the specific carbon content per cell. For the investigated activated sludge samples, the bacterial biomass measured by FCM was 588 mgCOD L(-1) on average in a two-months period. This value of active fraction corresponds to 14% of particulate COD. Active biomass values measured with the respirometric approach were consistent but generally higher than those obtained by FCM.