Influence of Childhood and Adolescent Fat Development on Fat Mass Accrual During Emerging Adulthood: A 20-Year Longitudinal Study

The relationships between emerging adults self-efficacy and motivation levels and physical activity: a cross-sectional study based on the self-determination theory

Objectives

The study aims to examine the associations between exercise self-efficacy, motivation, physical activity, and body composition among emerging adults.

Design

Cross-sectional.

Methods

A convenience sample of 147 emerging adults participated in the Releasing Weight (RELEW) project. The InBody720 analyzer was used to measure body composition, and the International Physical Activity Questionnaire-Short, the Shortened Physical Activity Self-Efficacy Scale, and the Treatment Self-Regulation Questionnaire were used to measure self-reported physical activity, self-efficacy, and motivation. Structural Equation Modeling was used to exam the complex relationships among multiple variables. in this study. The Partial least squares structural equation modeling analysis with bootstrapping in Smart PLS 3 was employed to explore the path coefficients and t-values for the relationships that were thought to exist. Significance was determined using a threshold of p < 0.05.

Results

The mean age of 147 participants was 18.5 ± 1.87, of whom 51.7% were female, recruited for this study. Exercise self-efficacy has a significant positive correlation with exercise motivation (r = 0.220, p = 0.008) and physical activity (r = 0.279, p < 0.001). Exercise motivation does not demonstrate significant associations with physical activity (r = 0.094, p = 0.298). Utilizing SEM, the model explained 9.2% of exercise self-efficacy, 11.8% of physical activity, and 68.3% of body composition variance. Mediation analysis revealed that exercise self-efficacy partially mediated the relationship between exercise motivation and physical activity (β = 0.106, t = 2.538, p < 0.05), and physical activity partially mediated the relationship between exercise self-efficacy and body composition (β = -0.296, t = 4.280, p < 0.001).

Conclusion

This study sheds light on the complex relationships among motivation, self-efficacy, physical activity and body composition during emerging adulthood. Our results highlight the mediating role of self-efficacy and its impact on physical activity behaviors, offering valuable insights for targeted interventions and policy development to improve health outcomes in this demographic.

Puberty timing and relative age as predictors of physical activity discontinuation during adolescence

Among same-age adolescents, those who enter puberty relatively later and those who are relatively younger (e.g., born later in the year) might be at greater risk of physical activity discontinuation. This study aimed to (1) describe gender-specific discontinuation, re-engagement, and uptake rates in various types of physical activities from the age of 11 to 17 years, and (2) assess puberty timing and relative age as predictors of discontinuation from organized, unorganized, individual, and group-based physical activities. Longitudinal data from 781 (56% girls, age 10-13 years at study baseline) Canadian participants who self-reported puberty status, birthdate, and involvement in 36 physical activities every four months from 2011 to 2018 was analyzed. The incidence of discontinuation, re-engagement, and uptake in organized/unorganized and individual/group activities from grade 6 until grade 12 was described and Cox proportional hazard models were used to estimate associations of puberty timing and relative age with organized/unorganized and individual/group activity discontinuation. Results demonstrate that individual and unorganized activities are maintained longer than group-based and organized activities. Girls who started puberty earlier were more likely to discontinue organized activities than girls with average-puberty timing [Hazard ratio (HR) (95% confidence interval (CI)) 1.68 (1.05-2.69)]. Compared to boys born in the 4th quarter of the year, boys born in the 2nd quarter of the year were less likely to discontinue organized [HR (95% CI) 0.41 (0.23-0.74)], unorganized [HR (95% CI) 0.33 (0.16-0.70)], group [HR (95% CI) 0.58 (0.34-0.98)], and individual activities[HR (95% CI) 0.46 (0.23-0.91)], and boys born in the 3rd quarter were less likely to discontinue unorganized activities[HR (95% CI) 0.41 (0.19-0.88)]. This study illustrates the patterns of physical activity participation throughout adolescence. However, the generalizability of findings may be limited due to participant representation.

Twenty-four-hour movement guidelines during adolescence and its association with obesity at adulthood: results from a nationally representative study

To determine the association between adherence to the 24-h movement guidelines during adolescence with obesity at adulthood 14 years later in a nationally representative cohort. We analyzed data from 6984 individuals who participated in Waves I (1994-1995) and IV (2008-2009) of the National Longitudinal Study of Adolescent Health (Add Health) in the USA. Obesity was defined by the International Obesity Task Force cut-off points at Wave I and adult cut-points at Wave IV (body mass index [BMI]≥30 kg/m2 and waist circumference [WC]≥102 cm in male and 88 cm in female). Physical activity, screen time and sleep duration were self-reported. Adolescents who met screen time recommendation alone (β = -1.62 cm, 95%CI -2.68 cm to -0.56), jointly with physical activity (β = -2.25 cm, 95%CI -3.75 cm to -0.75 cm), and those who met all three recommendations (β = -1.92 cm, 95%CI -3.81 cm to -0.02 cm) obtained lower WC at Wave IV than those who did not meet any of these recommendations. Our results also show that meeting with screen time recommendations (IRR [incidence rate ratio] = 0.84, 95%CI 0.76 to 0.92) separately and jointly with physical activity recommendations (IRR = 0.86, 95%CI 0.67 to 0.97) during adolescence is associated with lower risk of abdominal obesity at adulthood. In addition, adolescents who met all 24-h movement recommendations had lower risk of abdominal obesity later in life (IRR = 0.76, 95%CI 0.60 to 0.97).

CONCLUSION

Promoting the adherence to the 24-h movement guidelines from adolescence, especially physical activity and screen time, seems to be related with lower risk of abdominal obesity later in life, but not for BMI.

WHAT IS KNOWN

• Some studies have shown a relationship between adherence to 24-h movement guidelines and adiposity or obesity markers in youth. However, most of these studies have a cross-sectional design or a short follow-up.

WHAT IS NEW

• This is the first study which determined the association between adherence to the 24-h movement guidelines during adolescence with obesity at adulthood 14 years later in a nationally representative US cohort. • Meeting the 24-h movement guidelines from adolescence seems to be related with lower risk of abdominal obesity later in life, but not for body mass index.

A 4-Yr Mixed Longitudinal Study of Health Behaviors and Fat Mass Accrual during Adolescence and Early Adulthood

PURPOSE

Physical activity (PA), sedentary time (SED), and energy intake (EI) are associated with fat mass accrual in children and youth. Previous studies relied primarily on cross-sectional designs and proxy measures of body composition such as body mass index. We aimed to prospectively investigate associations between PA, SED, EI, and total body fat mass accrual using dual-energy x-ray absorptiometry.

METHODS

This analysis of the mixed longitudinal Healthy Bones III Study included data from 312 participants (138 boys age 9 to 21 yr at baseline). For each participant, we acquired a maximum of four annual total body dual-energy x-ray absorptiometry scans from which we determined fat mass (in kilograms; n = 748 observations). We assessed total PA, moderate-to-vigorous PA (MVPA) and SED with accelerometers (ActiGraph GT1M) and measured EI via 24-h dietary recall. We fit sex-specific multilevel models adjusting for maturity (years from age at peak height velocity (APHV)), weight status, ethnicity, total PA, MVPA, SED, and EI.

RESULTS

Boys and girls demonstrated divergent trajectories of fat mass accrual; rate of fat mass accrual in girls was four times greater than boys at APHV and increased across adolescence, whereas boys' fat mass plateaued after APHV. In boys, within-person change in MVPA negatively predicted fat mass independent of SED; each annual increase in MVPA of 6 min·d -1 was associated with a 0.21-kg lower fat mass. In girls, between-person average MVPA negatively predicted fat mass accrual independent of SED; greater MVPA of 4 min·d -1 across adolescence was associated with a 0.31-kg lower fat mass.

CONCLUSIONS

MVPA demonstrates an independent and negative effect on fat mass in boys and girls. Given different trajectories of fat mass accrual and movement behaviors between boys and girls, PA interventions aimed at preventing obesity in youth may benefit from a sex and gendered approach.

Neutral Effect of Increased Dairy Product Intake, as Part of a Lifestyle Modification Program, on Cardiometabolic Health in Adolescent Girls With Overweight/Obesity: A Secondary Analysis From a Randomized Controlled Trial

Background: The presence of obesity and some cardiometabolic disease risk factors in childhood and adolescence track into adulthood. Intake of dairy products has been shown to be inversely related to adiposity and cardiometabolic variables in youth. However, limited research has examined cardiometabolic disease risk factors following increased dairy product consumption as part of a lifestyle modification intervention in youth with overweight/obesity. This secondary analysis aimed to determine whether 12 weeks of increased dairy consumption, as part of a lifestyle modification program, affects cardiometabolic variables in adolescent females (range: 10-18 years) with overweight/obesity (BMI > 85th centile). Methods: Participants were randomized into two groups: higher dairy intake (RDa; four servings/day [to reflect previous Canada's Food Guide recommendations]; n = 23) or low dairy intake (LDa; 0-2 servings/day; n = 23). Both RDa and LDa participated in a 12-week, eucaloric, lifestyle modification intervention consisting of exercise training, and nutritional counseling. Adiposity (percent body fat [%BF]), dietary intake, and measures of cardiometabolic health were measured pre- and post-intervention. Results: There were no significant changes over time within groups or differences over time between groups for triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), TC/HDL ratio, low-density lipoprotein cholesterol (LDL), glucose, insulin, homeostatic model assessment of insulin resistance, adiponectin, and tumor necrosis factor alpha (TNF-α) (main effects of time and interactions, p > 0.05). Leptin decreased over the 12-week lifestyle intervention in both groups (main effect of time, p = 0.02). After combining the groups (n = 46), significant correlations were found between change in %BF and change in some cardiometabolic variables (HDL [r = -0.40], TC/HDL ratio [r = 0.42], LDL [r = 0.36], and TNF-α [r = 0.35], p < 0.05). After controlling for change in dairy product intake, the correlations were unchanged. Conclusion: Our findings demonstrate that increased dairy product consumption, as part of a lifestyle modification, weight management intervention, had a neutral effect on cardiometabolic disease risk factors in adolescent females with overweight/obesity. Change in dairy product intake did not influence the relationships between change in adiposity and change in cardiometabolic variables. Future research designed to primarily assess the effect of increased dairy product consumption on cardiometabolic disease risk factors in this population is warranted. Clinical Trial Registration: Clinicaltrials.gov; NCT#02581813.

Changes in Body Composition, Energy Expenditure, and Energy Intake during Four Years of University-A Follow-Up Study

Purpose: The transition to university is often accompanied by the adoption of negative lifestyle habits, which may result in weight and fat gain. While this has been demonstrated during 1st year, little is known about subsequent years. We investigated changes in body composition, energy expenditure, and dietary/energy intake from 1st to 4th year university. Methods: Thirty-eight students (14 males, 24 females) completed a lifestyle questionnaire and had their body mass, fat mass, lean body mass (LBM), and body fat percentage (%BF) measured three times: at the beginning and end of 1st year, and end of 4th year. Results: During 1st year, body mass, fat mass, LBM, and %BF increased (+3.2 ± 3.8 kg, +2.5 ± 3.0 kg, +0.7 ± 2.1 kg, +2.3 ± 4.9%, respectively; p < 0.01), while daily energy intake and expenditure decreased (-359 ± 1019 kcal·d-1 and -434 ± 786 kcal·d-1, respectively; p < 0.01). Between the end of 1st year and end of 4th year, body mass, LBM, and energy expenditure increased (+3.2 ± 3.8 kg, +1.3 ± 2.9 kg, +209 ± 703 kcal·d-1, respectively; p ≤ 0.05), while %BF, fat mass, and energy intake did not change. Conclusions: Although %BF and fat mass remained stable from the end of 1st year to the end of 4th year in this group of university students, the positive increase in energy expenditure was not enough to reverse the weight and fat gained during 1st year.

Impulsivity as a risk factor for weight gain and body roundness change among college freshmen

BACKGROUND

The college setting is considered an obesogenic environment due to high availability of palatable foods. However, only a minority of freshmen gain weight. Individual-level risk factors, such as impulsivity, may hold utility in predicting weight and adiposity changes. Individuals with an impulsive decision-making style may favor immediately rewarding foods at the expense of long-term health. Individuals who seek rewarding foods during strong emotions may also be at risk. The study tested decisional (delay-discounting; DD) and emotion-driven impulsivity (urgency) as risk factors for 1) weight and 2) body roundness change during freshman year.

METHODS

Freshmen (N = 103) completed questionnaires assessing DD, positive urgency (PU), and negative urgency (NU). Weight and body roundness index (BRI) were collected at the beginning and end of the academic year. Four repeated measures regression models examined impulsivity factors predicting change in 1) weight and 2) BRI. Models included baseline weight and height or BRI, respectively. Covariates included average daily caloric intake, energy expenditure from walking, and sex.

RESULTS

In models examining weight, neither DD nor NU were significantly associated with weight at follow-up (b = 0.008, p = .977; b = 0.280, p = .075) when holding covariates constant. In contrast, PU was significantly associated with weight at follow-up (b = 0.303, p = .033). In models examining BRI, DD (b = -0.039, p = .511) and PU (b = 0.049, p = .072) were not associated with BRI at follow-up. In contrast, NU was significantly associated with BRI at follow-up (b = 0.068, p = .017).

CONCLUSIONS

Emotion-driven impulsivity may be a risk factor for weight gain or change in body roundness during freshman year.

Relationship between abdominal adiposity, cardiovascular fitness, and biomarkers of cardiovascular risk in British adolescents

BACKGROUND

Puberty is a critical time in the development of overweight and obesity. The aim of this study was to examine relationships between measures of adiposity, cardiovascular fitness, and biomarkers of cardiovascular disease risk in adolescents.

METHODS

In a cross-sectional study design, 129 girls and 95 boys aged 12.9-14.4 years at various stages of puberty were included, along with their mothers (n = 217) and fathers (n = 207). Anthropometric assessments of adiposity were made, along with cardiovascular physical fitness, using the 20-m shuttle run test, and biomarkers associated with cardiovascular risk, including glucose, insulin, triglyceride, fibrinogen, and C-reactive protein (CRP) concentrations.

RESULTS

Waist-to-height ratio values were similar in boys and girls and correlated positively with diastolic blood pressure, insulin, triglyceride, fibrinogen, and CRP concentrations, and inversely with cardiovascular fitness scores. Skinfold thickness measurements were higher in girls. High-molecular-weight adiponectin concentrations were lower in boys than girls, particularly in late puberty, and CRP levels were higher. Cardiovascular fitness, maternal body mass index (BMI), and paternal BMI contributed independently to the variance in waist measurements in girls and boys. Gender, triceps skinfold thickness, and weight-to-height ratio, but not parental BMI, contributed independently to the variance in cardiovascular fitness.

CONCLUSION

There is a relationship between measures of adolescent adiposity and parental weight that involves factors other than cardiovascular fitness. Adolescent boys have relatively more abdominal fat than girls and a tendency to have a proinflammatory profile of biomarkers. These observations suggest that family and social environmental interventions are best undertaken earlier in childhood, particularly among boys.

Exploring the relationship between adolescent biological maturation, physical activity, and sedentary behaviour: a systematic review and narrative synthesis

CONTEXT

Across adolescence, there is a notable decline in physical activity in boys and girls. Maturational timing may be a risk factor for disengagement from physical activity and increased sedentary behaviours during adolescence.

OBJECTIVE

This systematic review aimed to summarise literature that examined the relationship between maturational timing, physical activity and sedentary behaviour in adolescents.

METHODS

Six electronic databases were searched for articles that assessed biological maturation and physical activity (including sports participation and active transportation) or sedentary behaviours in adolescents. Two reviewers conducted title, abstract, and full-text screening, reference and forward citation searches. Included articles were evaluated for quality using a standardised tool. A narrative synthesis was used to analyse the findings due to the heterogeneity of the studies.

RESULTS

Searches yielded 78 articles (64 unique studies) that met the inclusion criteria, representing 242,316 participants (153,179 unique). Studies ranged from 30.0% (low) to 91.7% (high) in quality. An inverse relationship between maturational timing and physical activity (in 50 and 60% of studies in boys and girls, respectively) and a positive relationship between maturational timing and sedentary behaviour (in 100% and 53% of studies in boys and girls, respectively) was most commonly reported. Evidence supporting an association between maturational timing, sports participation, and active transportation was inconsistent.

CONCLUSIONS

While this review demonstrates some evidence for early maturational timing as a risk factor for disengagement from physical activity and increase in sedentary behaviours, the reviewed literature also demonstrates that this relationship is complex. Future research that tracks maturity-related variations in physical activity and sedentary behaviours over adolescence is warranted.

Adipose Tissue Development and Expansion from the Womb to Adolescence: An Overview

Prevalence rates of pediatric obesity continue to rise worldwide. Adipose tissue (AT) development and expansion initiate in the fetus and extend throughout the lifespan. This paper presents an overview of the AT developmental trajectories from the intrauterine period to adolescence; factors determining adiposity expansion are also discussed. The greatest fetal increases in AT were observed in the third pregnancy trimester, with growing evidence suggesting that maternal health and nutrition, toxin exposure, and genetic defects impact AT development. From birth up to six months, healthy term newborns experience steep increases in AT; but a subsequent reduction in AT is observed during infancy. Important determinants of AT in infancy identified in this review included feeding practices and factors shaping the gut microbiome. Low AT accrual rates are maintained up to puberty onset, at which time, the pattern of adiposity expansion becomes sex dependent. As girls experience rapid increases and boys experience decreases in AT, sexual dimorphism in hormone secretion can be considered the main contributor for changes. Eating patterns/behaviors and interactions between dietary components, gut microbiome, and immune cells also influence AT expansion. Despite the plasticity of this tissue, substantial evidence supports that adiposity at birth and infancy highly influences its levels across subsequent life stages. Thus, a unique window of opportunity for the prevention and/or slowing down of the predisposition toward obesity, exists from pregnancy through childhood.

Relationship Between Trajectories of Trunk Fat Development in Emerging Adulthood and Cardiometabolic Risk at 36 Years of Age

OBJECTIVE

This study examined trajectories of trunk fat mass (FM) accrual during emerging adulthood of individuals categorized, at 36 years of age, as having higher compared with lower scores of (1) metabolic risk and (2) blood pressure risk.

METHODS

Fifty-five individuals from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2017) were assessed from adolescence (mean [SD], 11.5 [1.8] years) through emerging adulthood (26.2 [2.2] years) and into early adulthood (35.6 [2.2] years) (median 11 visits per individual). Sex-specific median splits of continuous standardized risk scores at 36 years of age were created. Dual-energy x-ray absorptiometry-assessed trunk FM trajectories were analyzed using multilevel random effects models.

RESULTS

Higher risk scores of blood pressure risk and metabolic risk had significantly steeper trajectories of fat development (0.45 [0.11] and 0.44 [0.11] log g, respectively) than the lower risk scores. Dietary fat was not related (P > 0.05). Physical activity was negatively related (-0.04 [0.02] physical activity score) to trunk FM development during emerging adulthood.

CONCLUSIONS

Young adults with higher metabolic risk at 36 years of age had greater trunk FM development during both adolescence and emerging adulthood, supporting the need for intervention at both these critical periods of fat accrual.

Long-term childhood body mass index and adult bone mass are linked through concurrent body mass index and body composition

Body mass plays a crucial role in the bone growth and development, but few studies have examined the association of long-term cumulative impact and trajectory patterns of childhood body mass index (BMI) with adult bone mass, and the mediation effect of adult BMI and body composition on these associations. A total of 397 Chinese adults (54.4%) who had been examined for BMI 4-8 times during childhood (6-19 years) and bone mass in adulthood (29-37 years), were included for analysis. Adult bone mineral content (BMC), areal bone mineral density (aBMD) and body composition were assessed via dual-energy x-ray absorptiometry. Childhood BMI growth curves were constructed using a random-effects mixed model. The area under the curve (AUC) was calculated to represent the long-term impact of childhood BMI. At baseline, 24.4%, 66.2%, 7.6% and 1.8% of the participants were underweight, normal weight, overweight and obese, respectively. Quadratic curve parameters of childhood BMI differed significantly between groups of adult whole body (WB) BMC, lumbar spine (LS) aBMD and femoral neck (FN) aBMD, with low BMC/aBMD groups having lower childhood BMI than the normal groups. AUC of childhood BMI was significantly and positively related to adult WB BMC and aBMD at each site, irrespective of sex. Significant mediation effects of adult BMI were shown on the association of childhood BMI AUC with adult WB BMC in males (52.0%) and FN aBMD in both sexes (males: 65.4%; females: 64.3%). Additionally, mediation effect of fat mass index was only noted on the association of childhood BMI AUC with adult WB BMC (41.3%), with a positive total indirect effect estimated at 0.118. The adult lean mass index, by contrast, mediated the childhood BMI-adult BMC/aBMD association positively at all sites in males (71.5%~89.2%) and at WB BMC in females (45.0%). These findings suggest that the impact of body weight on adult bones originates from childhood, which is mediated by concurrent BMI and body composition.

At what age do normal weight Canadian children become overweight adults? Differences according to sex and metric

BACKGROUND

The prevalence of overweight and obesity doubles between adolescence and young adulthood; however, the exact age, and appropriate metric to use to identify when overweight develops is still debated.

AIM

To examine the age of onset of overweight by sex and four metrics: body mass index (BMI), fat mass (%FM), waist circumference (WC) and waist-to-height ratio (WHtR).

SUBJECTS AND METHODS

Between 1991 and 2017, serial measures of body composition were taken on 237 (108 males) individuals (aged 8-40 years of age). Hierarchical random effects models were used to develop growth curves. Curves were compared to BMI, %FM and WC overweight age- and sex-specific cut-points.

RESULTS

In males, the BMI growth curve crossed the cut-point at 22.0 years, compared to 23.5 and 26.5 years for WHtR and %FM, respectively; WC cut-off was not reached until 36 years. In females, the BMI growth curve crossed the overweight cut-point at 21.5 years, compared to 14.2 years for %FM and 21.9 and 27.5 years for WC and WHtR, respectively.

CONCLUSION

In summary, overweight onset occurs during young adulthood with the exception of WC in males. BMI in males and %FM in females were the metrics identifying overweight the earliest.