Modifying influence of dietary sugar in the relationship between cortisol and visceral adipose tissue in minority youth

Racial/ethnic differences in dietary intake among a diverse sample of adolescents: An experimental study

BACKGROUND

African-American (AA) and Hispanic/Latina (HL) females have higher obesity prevalence than do non-Hispanic Whites (NHW); this may be due to AA and HL consuming more energy-dense foods in response to stressors.

OBJECTIVES

This study examined racial/ethnic differences in dietary intake under controlled conditions (relaxation and stress) in a diverse sample of adolescent females.

METHODS

Participants included 120 adolescent females (30% AA, 37% HL and 33% NHW) who participated in a laboratory food intake study. Using a randomized cross-over design, ad libitum food consumption was measured following control/relaxation and social-evaluative stress conditions. Food intake was indexed as consumed calories, added sugars and solid fats.

RESULTS

The effect of laboratory conditions on food intake varied by race/ethnicity, such that AA consumed more energy following relaxation than following stress. For NHW and HL, food intake did not differ between conditions.

CONCLUSIONS

To the best of our knowledge, these findings are the first to directly observe racial/ethnic differences in food intake in response to acute stress, which may contribute to obesity-related health disparities.

Sleep, social behaviour and food consumption of schoolchildren of a large Brazilian city

OBJECTIVE

To explore the impact of inadequate sleep and associated factors on the social behaviour and food consumption of children and adolescents.

DESIGN

Cross-sectional study.

SETTING

Sleep information, social behaviour (Strengths and Difficulties Questionnaire), food consumption, demography, nutritional status, lifestyle, and biochemical tests were investigated.

PARTICIPANTS

School children in the 4th grade of the municipal school system of a large Brazilian city.

RESULTS

Of a total of 797 schoolchildren, 50·9 % were female, with a median age of 9·7 (9·5-10·0) years old and an energy consumption of 7613·6 (5982·7-9766·2) kJ. It was determined that 31·6 % were overweight, and 76·8 % reported insufficient weekly practice of physical activity. A median of 9·6 (8·9-10·5) h of sleep (lower values on weekdays: 9·3 v. 10·5 h, P < 0·001) was recorded. In addition, 27 % of the individuals who experienced inadequate sleep (<9 h) engaged in longer screen time daily (≥2 h/d) (P = 0·05), had an inadequate bedtime (> 22 h) or adequate wake-up time (5-7 h), studied in the morning (P < 0·001) and never took a shower before school (P < 0·001). Of the entire sample, 9·9 % had poor or very poor sleep quality and a greater probability of sleep talking regularly, had difficulty falling asleep, and engaged in inadequate social behaviour while experiencing these conditions compared with those with positive sleep quality. There was no association between sleep and the other variables investigated.

CONCLUSIONS

Sleep impairment contributed to changes in sleep and social behaviour in schoolchildren. The findings of this study may reinforce the importance of developing actions to promote adequate sleep and a healthy lifestyle at school age.

Sugar-sweetened beverage consumption is associated with visceral fat in children

Sugar-sweetened beverage (SSB) consumption has been associated with visceral fat partitioning in adults; however, the underlying mechanisms in childhood remain unclear and warrant exploration. This cross-sectional study aimed to investigate the association between SSB consumption and body fat in children aged 9-13 years and the potential modifying effect of children's sex and serum cortisol levels. A sample of 2665 Greek schoolchildren participated in the 'Healthy Growth Study', and anthropometric, body composition, dietary intake and serum cortisol data were assessed. SSB consumption was defined as low (<1 serving/d), medium (1-2 servings/d) or high (>2 servings/d). We used linear regression models to assess the association between SSB consumption and measures of adiposity and to assess effect modification; models were stratified by sex and tertiles of morning serum cortisol. A significant positive association was observed between high SSB consumption and visceral adipose tissue (VAT) (β = 1·4, 95 % CI 0·4, 2·3, P = 0·01) but not BMI or BMI z-score. When stratified by sex, the association was observed in boys (β = 1·8, 95 % CI 0·3, 3·4, P = 0·02) but not in girls. When stratified by cortisol levels, SSB consumption was associated with VAT in children with cortisol levels in the lowest tertile (β = 2·8, 95 % CI 1·0, 4·6, P < 0·01). These results indicate that increased SSB consumption is associated with visceral adiposity in schoolchildren and this association may be modified by sex and morning serum cortisol. To prevent VAT accumulation and concomitant disease risk, dietary interventions should target SSB consumption during childhood.

Short-term changes in added sugar consumption by adolescents reflected in the carbon isotope ratio of fingerstick blood

BACKGROUND

Consumption of added sugars (AS) and sugar-sweetened beverages (SSB) may adversely affect adolescents' weight and cardiovascular disease risk. Reliance on self-reported dietary assessment methods is a common research limitation, which could be overcome by dietary intake biomarkers.

AIM

The investigation was a proof-of-concept study to evaluate the proposed carbon isotope ratio (δ¹³C) biomarker of AS intake in adolescents, using a controlled feeding design.

METHODS

Participants (n = 33, age 15.3 years, 53% female) underwent two seven-day controlled feeding periods in a randomly assigned order. Diets were matched in composition except for AS content (5% or 25% of total energy). Fasting fingerstick blood samples were collected daily during each diet period.

RESULTS

Fingerstick δ¹³C values changed from day 1 to 8 by -0.05 ± 0.071‰ on 5% AS, and +0.03 ± 0.083‰ on 25% AS (p ≤ 0.001). Reliability was demonstrated between day 7 and 8 δ¹³C values on the 5% (ICC = 0.996, p ≤ 0.001) and 25% (ICC = 0.997, p ≤ 0.001) AS diets.

CONCLUSIONS

Larger scale investigations are warranted to determine if this technique could be applied to population-level research in order to help assess the effectiveness of interventions aimed at reducing the consumption of AS or SSB intake.

Reduced brain response to a sweet taste in Hispanic young adults

Hispanics have an increased risk for metabolic disorders, which evidence suggests may be due to interactions between lifespan biological, genetic, and lifestyle factors. Studies show the diet of many U.S. Hispanic groups have high sugar consumption, which has been shown to influence future preference for and consumption of high-sugar foods, and is associated with increased risk for insulin-related disorders and obesity. Taste is a primary determinant of food preference and selection. Differences in neural response to taste have been associated with obesity. Understanding brain response to sweet taste stimuli in healthy Hispanic adults is an important first step in characterizing the potential neural mechanisms for this behavior. We used fMRI to examine brain activation during the hedonic evaluation of sucrose as a function of ethnicity in Hispanic and non-Hispanic young adults. Taste stimuli were administered orally while subjects were scanned at 3T. Data were analyzed with AFNI via 3dROIstats and 3dMEMA, a mixed effects multi-level analysis of whole brain activation. The Hispanic group had significantly lower ROI activation in the left amygdala and significantly lower whole brain activation in regions critical for reward processing, and hedonic evaluation (e.g. frontal, orbitofrontal, and anterior cingulate cortices) than the non-Hispanic group. Differences in processing of sweet tastes have important clinical and public health implications, especially considering increased risk of metabolic syndrome and cognitive decline in Hispanic populations. Future research to better understanding relationships between health risk and brain function in Hispanic populations is warranted to better conceptualize and develop interventions for these populations.

Associations among sugar sweetened beverage intake, visceral fat, and cortisol awakening response in minority youth

CONTEXT

Abdominal adiposity has long been associated with excess caloric intake possibly resulting from increased psychosocial stress and associated cortisol dysfunction. However, the relationship of sugar-sweetened beverage (SSB) intake specifically with cortisol variability and visceral adipose tissue (VAT) is unknown.

OBJECTIVE

To examine the relationships between SSB intake, VAT, and cortisol response in minority youth.

DESIGN

A cross-sectional analysis.

SETTING

The University of Southern California.

PARTICIPANTS

60 overweight/obese Non-Hispanic Black and Hispanic adolescents ages 14-18years.

MAIN OUTCOME MEASURES

VAT via Magnet Resonance Imaging (MRI), cortisol awakening response (CAR) via multiple salivary samples, and SSB intake via multiple 24-hour diet recalls. SSB intake was divided into the following: low SSB consumers (<1 servings per day), medium SSB consumers (≥1-<2 servings per day), high SSB consumers (≥2 servings per day). Analysis of covariance were run with VAT and CAR as dependent variables and SSB intake categories (independent variable) with the following a priori covariates: sex, Tanner stage, ethnicity, caloric intake, and body mass index.

RESULTS

The high SSB intake group exhibited a 7% higher VAT compared to the low SSB intake group (β=0.25, CI:(0.03, 0.33), p=0.02). CAR was associated with VAT (β=0.31, CI:(0.01,0.23), p=0.02). The high SSB intake group exhibited 22% higher CAR compared to the low SSB intake group (β=0.30, CI:(0.02,0.48), p=0.04).

CONCLUSION

This is the first study exploring the relationship between SSB, VAT, and CAR. SSB consumption appears to be independently associated greater abdominal adiposity and higher morning cortisol variability in overweight and obese minority youth. This study highlights potential targets for interventions specifically to reduce SSB intake in a minority youth population.