Purpose: Weight loss in obesity is often achieved by calorie restriction and increased energy expenditure. A gradual return to previous eating habits makes success a challenge. Ghrelin, an orexigenic hormone secreted by the stomach may be elevated among obese individuals. It may play a role in activation of the reward systems of the brain, and influence feelings of hunger to motivate consumption of food. The response of hormones regulating appetite and hunger to different types of nutrients may help to understand this. Thus, the objective of this study is to observe the change in plasma ghrelin to two isocaloric meals with a %fat composition of 30 and 50.

Methods: Twelve male participants with normal BMI, between the ages of 18 and 22 recruited by advertisement, enrolled in this cross-over experiment. Informed consent was obtained before commencement of the experiments. Basic anthropometric measurements were made including height (Seca, Hamburg, Germany), weight and body composition (Tanita, Tokyo, Japan). In the first experiment, one of 2 isocaloric meals containing either 30 or 50% fats was administered in random order determined by a coin toss after an overnight fast. A second experiment was conducted at least 4 days later with the other meal given similarly. A fasting serum ghrelin and ghrelin 1 hour after consumption of each meal was analysed by immunoassay using a commercially available kit (Elabscience, Texas, USA) and measured in ng/ml.

Results/findings: Participants had a BMI of 22±2 kg/m2and % body fat of 18.5 ±5. Ghrelin levels decreased by an average of 34% and 20% after the high fat meal which was statistically significant (p<0.025), and low fat meal respectively, when compared to baseline levels.

Conclusions: Thus within this study group, ghrelin levels measured one hour after consuming a meal decreased significantly with a high fat meal. This finding may help to understand and manipulate fat content of a meal to achieve lower post-meal ghrelin levels. Further investigation into whether this translates to greater satiety levels is needed.

Purpose: High-intensity interval training (HIIT) elicits equal or superior health benefits to moderate intensity continuous training (MICT) in a supervised setting. Self-directed participation in HIIT following supervised training has not been widely examined. Therefore, we aimed to determine the feasibility and efficacy of home-based combined aerobic and resistance HIIT (C-HIIT) compared with combined MICT (C-MICT) after a supervised period in people with type 2 diabetes (T2D).

Methods: Fifty-seven adults with T2D (63% male, age 61±9y, HbA_1c 7.7±1.2%) completed 8weeks of supervised C-HIIT (1x4min HIIT @ 85-95% HR_peak plus 8x1min resistance training, 3times/week) or C-MICT (52.5min @ 55-69% HR_peak, 2times/week; 22.5min @ 55-69% HR_peak plus 30min resistance training, 2times/week), before completing 10months of self-directed, home-based training. Feasibility was assessed via adherence to the exercise prescription and face-to-face interviews. Efficacy was assessed via changes in cardiorespiratory fitness (CRF; ml/kg/min) and leg press 1 repetition maximum (1RM; kg). The quantitative data were analysed using one-way ANCOVA. The qualitative data was analysed using a thematic analysis.

Results: C-HIIT and C-MICT participants completed 48% and 67% of the prescribed sessions respectively during the home-based training period, with 63% and 80% adherence to the prescribed intensities. The key barriers to C-HIIT were identified as lack of access to specialised equipment and lack of supervision. After 8weeks, there were similar improvements in CRF (C-HIIT: mean difference (MD) 0.9ml/kg/min, 95% CI [-0.2, 1.9], p=0.12; C-MICT: MD 1.9ml/kg/min [0.2, 1.8], p=0.02) and 1RM (MD 17.0kg, [-3.9, 37.9], p=0.15) between groups. At 12months, CRF improved further in C-MICT (MD 1.3ml/kg/min [0, 2.6], p=0.04), but the improvement in C-HIIT (MD 1.2ml/kg/min [-0.3, 2.7]) was not significant (p=0.10). There was no between-group difference in 1RM after 12months (MD -15.4kg [-37.1, 6.3], p=0.15).

Conclusions: This is the first study to compare the feasibility and efficacy of high- and moderate intensity combined aerobic and resistance training in people with T2D. It highlights the need for strategies to enhance long-term HIIT participation in people with T2D, with focus around equipment access and supervision.

Purpose: Birth weight has been linked to infant morbidity and mortality, childhood development and health status in adulthood. Past studies indicate the link between pre-pregnancy body mass index (BMI) and infant birth weight. Maternal nutrition is also recognised as one of the key determinants of fetal growth. This study examined whether mother’s weight status before pregnancy and their dietary habits during third trimester predict infant’s birth weight.

Methods: This study used baseline data from a randomised controlled trial of Communicating Healthy Beginnings Advice by Telephone, conducted in four local health districts in New South Wales, Australia. Women in their third trimester of pregnancy were included. Telephone survey was used to collect baseline data such as the women’s demographic background, pre-pregnancy BMI, dietary habits including fruits, vegetables, processed meat, chips, fast foods, soft drinks, and juice consumption, gestational diabetes and smoking status. Infant birth weight data were collected using a second telephone survey while the baby was 6 months of age. Multivariate regression modelling was used to determine the factors predicting low (<2,500g) and high (≥4,000g) birth weight.

Results/findings: Data were available for 1,154 participants. The majority of the infants (86%) were within normal birthweight, 4% were classified as low birth weight while 10% were classified as high birth weight. Findings indicate high consumption of soft drinks (ARR= 2.30, p<0.05), chips (ARR= 0.30 p<0.05), and fast food (ARR= 1.54, p<0.05) during pregnancy were associated with infant’s low birth weight. Mothers who were obese before their pregnancy (pre-pregnancy BMI ≥30) (ARR= 2.01, p<0.05) were associated with infant’s high birth weight.

Conclusions: The study findings revealed that mother’s weight status and certain dietary behaviours during pregnancy could play significant role in infant birth weight. These findings support the need of intervention to promote healthy weight status among women who plan for pregnancy as well as to promote less junk food consumption during pregnancy in order to reduce the risk of unhealthy infant birth weight.

Purpose: Waist circumference is an ideal anthropometric measure for abdominal obesity and a predictor of insulin resistance, independent of body mass index (BMI) in youth. The objective of this study is to develop optimal age- and sex-specific waist circumference cut-points for identifying risk of Acanthosis nigricans among 2 – 8-year-old US Affiliated Pacific (USAP) children.

Methods: A cross-sectional secondary analysis examined 4023 children from data collected in 2012 – 2013 from the Children’s Healthy Living Program. Height, weight, and waist circumference measurements and the observation of Acanthosis nigricans were assessed by trained staff. Receiver-operating characteristic (ROC) analysis was used to estimate the age- and sex-specific waist circumference sensitivity and specificity to detect Acanthosis nigricans. Youden’s Index (J) determined the optimal waist circumference cut- off points by sensitivity + specificity - 1 with a range from 0 and 1. These cut-points are compared to the 90^thpercentile, which is the International Diabetes Federation criteria for children 6 years and older.

Results: Overall, waist circumference increased with age among boys and girls. The 90^th percentile for boys ages 2 – 5 years (58.15 cm) and 6 – 8 years (71.63 cm) were slightly higher than girls for both age groups (girls: 2 – 5 years: 57.97 cm and 6 – 8 years: 70.37 cm). In a model including both sexes, the highest sensitivity and specificity for identifying Acanthosis nigricans had a value of 60.0 cm, equivalent to the 85^th percentile. The optimal cut-points for identifying Acanthosis nigricans for boys, 2 – 5 years (53.25 cm) was at the 75^th percentile and 6 – 8 years (63.63 cm) at the 80^th percentile. For girls he cut-point for ages 2 – 5 years (58.24 cm) was at the 90^th percentile and 6 – 8 years (63.60 cm) was at the 80^th percentile.  

Conclusions: In USAP children, waist circumference was shown to be a predictor for identifying Acanthosis nigricans. Further longitudinal analysis is warranted to confirm Acanthosis nigricans at lower waist circumference percentiles than expected. These cut-points provide an estimate for epidemiological and possibly clinical applications for early detection and prevention of Type 2 Diabetes. 

Purpose: Anxiety, characterized by excessive uncontrolled worry or concern, is associated with increased risk of disordered eating; however little is known about how anxiety is related to specific weight-related concerns (eating concern, shape concern, weight concern) and behaviors (restraint eating, inappropriate weight-management behaviors). Thus, this study examined links between anxiety, weight-related concerns and behaviors, and overall disordered eating risk.

Methods: Young adults (n=1792, 65% female, age=20.36±1.32SD years) completing an online survey comprised of all Eating Disorder Exam Questionnaire (EDE-Q) assessments (eating, shape, and weight concerns; restraint and binge eating; inappropriate weight-management behaviors) were divided into 3 groups based on Generalized Anxiety Disorder-7 (GAD-7, alpha=0.93) scale score (7-item, 4-point Likert; possible score 0-21): low (score <7; n=991), moderate (score ≥7 to <14; n=625), or high (score ≥14; n=286) anxiety.

Results: ANOVA with Tukey post hoc tests revealed the low anxiety group had significantly (p<0.01) less concerns about eating, shape, and weight and were less likely to engage in restraint eating, binge eating, or use inappropriate weight-management behaviors (i.e., vomiting, laxative use, excessive exercise) than both the moderate and high anxiety groups. Similarly, the moderate anxiety group had significantly less eating, shape, and weight concerns and restraint and binge eating behaviors than the high anxiety group. Use of inappropriate weight-management behaviors did not differ between moderate and high anxiety groups. Overall disordered eating risk scores increase with anxiety, with all groups differing significantly from each other.

Conclusion: Anxiety is associated with every concern and behavior assessed by the EDE-Q, as well as overall EDE-Q score. The prevalence of moderate to high anxiety in young adults (48% of this sample), the links elucidated between weight-related concerns and behaviors, and the risks these concerns and behaviors pose to immediate and long-term health all suggest that nutrition interventions targeting young adults should consider incorporating anxiety reduction tools and evaluating the potential for these accessory tools to improve overall health.

Purpose: Sedentary behavior (SB) may be detrimental to the health of different populations, but in children and adolescents it is unclear whether young people with high SB would have lower bone mineral density (BMD) and whether such results would be independent of confounding factors such as somatic maturation and physical activity (PA). 

Objectives: To compare the BMD of different sites according to the level of different types of SB in children and adolescents. 

Methods: The sample consisted of 88 students (54 males) aged 9.5 ± 1.5 years of Presidente Prudente-SP, Brazil. SB was evaluated by the number of hours of TV, computer, video game and smartphone use. The total SB was evaluated by the sum of the number of hours in the different screen devices. Children were divided into tertiles according to each SB. The BMD on each site and the entire body has been evaluated by DEXA. Somatic maturation was calculated using the Maturity Offset estimation formula, in which values of weight, height, trunk and leg length were used. PA was assessed using the questionnaire developed by Baecke et al. The comparison of the different types of BMD sites according to the SB levels by each screen device and the total SB were analyzed by ANCOVA adjusted for sex, age, somatic maturation, lean mass and PA. .

Results: Children and adolescents classified with low video game use had higher BMD-legs compared with high video game use peers (P= 0.013; F= 4.567). Young people as well as to those with moderate use of this device (P= 0.035; F= 3,496). Children and adolescents with low total SB had higher BMD-legs than young people with high total SB, but this relationship is mitigated after adjustment for PA (P= 0.068; F= 2.775). Whole body BMD was higher in young people with low total SB than in those with moderate and high SB (P=0.011; F=8.333). 

Conclusions: Adolescents with high SB tend to have lower whole body BMD compared to those with low sedentary behavior.