Self-Esteem and Change in Body Mass Index over 3 Years in a Cohort of Adolescents

Self-esteem has been hypothesized to be lower in obese adolescents relative to their normal weight peers and to be an important factor in preventing or reversing obesity. The present study examined the relationship between obesity and self-esteem cross-sectionally and prospectively over three years in a cohort of 1278 adolescents in grades 7 to 9 at baseline. Cross-sectional analyses revealed an inverse association between physical appearance self-esteem and body mass index in both males and females. In females, body mass index was inversely associated with global self-esteem, close friendship, and behavioral conduct self-esteem. In males, body mass index was inversely associated with athletic and romantic appeal self-esteem. Prospectively, in females, physical appearance and social acceptance self-esteem at baseline were inversely related to body mass index three years later. Baseline self-esteem was unrelated prospectively to change in body mass index in males. All associations were modest in magnitude. These results suggest that in a middle class white sample of adolescents, self-esteem specific to physical appearance is modestly associated with body mass index. Low self-esteem does not appear to predict the development of obesity over time.     

Asthma and Maternal Body Mass Index Are Related to Pediatric Body Mass Index and Obesity: Results from the Third National Health and Nutrition Examination Survey

Objective: Clinical research has shown an increased prevalence of obesity in children with asthma. This study was designed to assess the relationship between asthma and pediatric body mass index (BMI) in a national database and to examine factors that may modify this relationship. Design: The cross‐sectional relationship between asthma and pediatric BMI and obesity (BMI ≥ 85th percentile) was studied. Variables that may influence the relationship between asthma and pediatric BMI, such as race/ethnicity and television watching were included in the model for the total sample. A smaller sample of 3009 white and African American youth were studied in regression models including maternal BMI. Study Population: A nationally representative crosssectional sample of 5154 children and adolescents of 6 to 16 years of age from the Third National Health And Nutrition Examination Survey. Results: In the full sample, asthma and television watching were related to BMI, accounting for 3% of the variance in BMI. When maternal BMI was included in the nonHispanic sample, television watching, maternal BMI, and the interaction of maternal BMI and asthma were related to youth BMI, accounting for 15% of the variance. The standardized BMI z‐score for those youth without asthma and no maternal obesity was 0.06, which increased to 0.33 if the youth had asthma, to 0.70 if the youth did not have asthma but the mother was obese, and to 1.71 if the youth had asthma and the mother was obese. Asthma, television watching, and maternal BMI were independent predictors of youth obesity. Conclusions: BMI and prevalence of obesity is higher in youth with asthma. Pediatric BMI, but not obesity, is also related to the interaction of asthma and maternal BMI in white and African American youth. Comorbidity of asthma and obesity may complicate treatment of either condition, and prevention of obesity should be encouraged for asthmatic children.     

Body Mass Index and Coronary Artery Disease in African-Americans

There are limited data available concerning the influence of obesity, a major cardiovascular disease risk factor, in relationship to coronary artery disease (CAD). This is of considerable importance to African-Americans since African-Americans have one of the world's highest CAD mortality rates coupled with the fact that obesity is extremely prevalent in this population. The present study assessed the relationship between body mass index and CAD in African-Americans undergoing coronary angiography. Eight hundred sixty-six available cardiac catheterization reports between the years 1983 through 1990 were retrospectively reviewed at Howard University Hospital in Washington, D.C. CAD was prevalent in 59.6% and 41.2%, males and females, respectively. Among the males overweight and obesity were found in 22.4% and 20.9%, respectively, compared to 39.6% and 30.6% for females. An upside-down U-shaped relationship between BMI and CAD was found. The interpretation of this finding is that being overweight is associated with increased risk of CAD compared to the lean and obese.     

The Relationship Between Body Image Discrepancy and Body Mass Index Across Ethnic Groups

Objective: This study sought to examine at what body mass index (BMI) body image discrepancy (BD) was reported in a community sample of 389 white, Hispanic, and black women. In addition, we assessed the trajectory of the BMI–BD relationship as BMI increases by ethnic group. Research Methods and Procedures: All participants were assessed on height and weight and completed the Figure Rating Scale. Results: We found no difference in the proportion of women in each ethnic group reporting BD. However, white women experienced BD at a lower BMI level (BMI = 24.6), and below the criterion for overweight (BMI = 25). In contrast, black and Hispanic women did not report BD until they were overweight (BMIs of 29.2 and 28.5, respectively). Compared with black and white women, Hispanic women registered increases in BD at smaller increases in BMI. Discussion: These findings could have unhealthful implications for weight control behavior. The results encourage a closer look at ethnicity and BD, and their relationship to obesity and weight control.     

Body Mass Index and the Prevalence of Hypertension and Dyslipidemia

Objective: To describe and evaluate relationships between body mass index (BMI) and blood pressure, cholesterol, high‐density lipoprotein‐cholesterol (HDL‐C), and hypertension and dyslipidemia. Research Methods and Procedures: A national survey of adults in the United States that included measurement of height, weight, blood pressure, and lipids (National Health and Nutrition Examination Survey III 1988–1994). Crude age‐adjusted, age‐specific means and proportions, and multivariate odds ratios that quantify the association between hypertension or dyslipidemia and BMI, controlling for race/ethnicity, education, and smoking habits are presented. Results: More than one‐half of the adult population is overweight (BMI of 25 to 29.9) or obese (BMI of ≥30). The prevalence of high blood pressure and mean levels of systolic and diastolic blood pressure increased as BMI increased at ages younger than 60 years. The prevalence of high blood cholesterol and mean levels of cholesterol were higher at BMI levels over 25 rather than below 25 but did not increase consistently with increasing BMI above 25. Rates of low HDL‐C increased and mean levels of HDL‐C decreased as levels of BMI increased. The associations of BMI with high blood pressure and abnormal lipids were statistically significant after controlling for age, race or ethnicity, education, and smoking; odds ratios were highest at ages 20 to 39 but most trends were apparent at older ages. Within BMI categories, hypertension was more prevalent and HDL‐C levels were higher in black than white or Mexican American men and women. Discussion: These data quantify the strong associations of BMI with hypertension and abnormal lipids. They are consistent with the national emphasis on prevention and control of overweight and obesity and indicate that blood pressure and cholesterol measurement and control are especially important for overweight and obese people.     

Associations of Body Mass and Body Fat Distribution with Parity Among African-American and Caucasian Women: The CARDIA Study

Associations of parity with body fat and its distribution are poorly understood; therefore, we examined the relationships between parity and obesity in young adult women. Body mass index (BMI), skin folds, and waist-hip ratio were compared in 1452 African-American and 1268 Caucasian nonpregnant women aged 18 to 30, adjusting for age (where no age-parity interactions were present), education, physical activity (assessed by questionnaire) and fitness (assessed by graded exercise test), dietary fat intake, alcohol and smoking. Adjusted mean BMI was significantly higher in African-American women aged 25–30 years with three or more children (28.5 kg/m²) than in those with two (27.0 kg/m²), one (26.2 kg/m²), or no children (26.3 kg/m²). Similar trends were found in Caucasians (BMI = 23.3, 23.4, 23.7, 25.0 kg/m² for parity = 0,1, 2, ≥ 3, respectively), but the mean BMI was significantly higher in African Americans in each parity group. The association between BMI and parity was not present among women 18–24 years of age. Skinfolds were directly associated with parity in African Americans only. Waist-hip ratios were generally lower among nulliparous than parous women in both ethnic groups; race differences were present only among nulliparas. In conclusion, parity was associated with BMI in women aged 25 to 30 years but did not explain ethnicity-related differences in body mass.     

驻某地武警机关干部体质指数与代谢性疾病的关系

目的:探讨健康体检的驻某地武警机关干部体质指数(BMI)与代谢性疾病的关系。方法:采用横断面调查方法对健康体检的1920名驻某地武警机关干部和270名地方机关干部的体质指数情况进行比较分析,探讨超重肥胖与代谢性疾病的关系。结果:1.军人组超重率及肥胖率均低于地方组(P<0.01)。2.<50岁人群组随年龄增加,超重及肥胖检出率有增高趋势(P<0.01),40~49岁人群超重率和肥胖率最高;50~65岁人群超重与肥胖率最低。3.两组机关干部随BMI升高,高总胆固醇、高甘油三酯、高尿酸血症、脂肪肝检出率增高(P<0.01);军人组高尿酸血症发病率明显高于地方组(P<0.05);高血压、高血脂发病率明显降低(P<0.05);与地方超重组比较,军人超重组脂肪肝发病率明显升高(P<0.05)。4.在30~50岁的军人中,随着年龄升高,高血压、高血糖、高血脂、高尿酸,脂肪肝发病率明显升高(P<0.01)。结论:健康体检人群超重、肥胖率较高,控制体重对高血压、高血糖、高血脂及脂肪肝等慢性病的防治具有重要意义。军人组超重与肥胖率均低于地方,但高尿酸血症和高脂肪肝发病率升高,故建议有代谢性疾病的军人限制饮酒可能会受益。     

Black and White Females' Perceptions of Ideal Body Size and Social Norms

Different cultural norms and standards for appropriate female body size might contribute to the disparity in obesity rates between black and white adult females (46.0% and 24.6% respectively). The purpose of this study was to measure adolescents' perceptions of ideal size and social norms regarding female body size as well as adolescents' perceptions of significant others' evaluation and expectations of the adolescents' body size. Subjects included 437 adolescent girls (247 white and 190 black) aged 13 to 19 (x=44.9, SD=.979) from six randomly selected public schools. The subjects, heights and weights were measured. Responses to a body image questionnaire and a series of nine female body drawings (arranged ordinally, 1 to 9, from thinnest to heaviest) were analyzed using the General Linear Model and Logistic Regression. The female body size considered ideal by black females was significantly larger than the size selected as ideal by white females (x= 3.47 and x= 3.13 respectively, p< 0.001). Black females were two times more likely than white females to describe themselves as thinner than other girls their age (O.R. = 2.01, 95% C.I.1.34, 3.01) and seven times as likely to say that they were not overweight (O.R. = 7.08, 95% C.I. 3.72, 13.45). White females wanted to be a smaller size than they currently were and felt encouraged by significant others to lose weight or reduce their size. Black females did not indicate as great a desire as whites to be smaller and they tended to feel that their size was considered satisfactory by significant others. Only subjects from the low SES group perceived that significant others wanted them to gain weight. The differences between black and white subjects' beliefs and perceptions about body size norms may explain, in part, why heavier body weights persist in some cultural groups.     

Relationship between Body Mass Index and the Use of Healthcare Services in Australia

Objective: To examine the relationship between body mass index (BMI) and the use of medical and preventive health services. Research Methods and Procedures: This study involved secondary analysis of weighted data from the Australian 1995 National Health Survey. The study was a population survey designed to obtain national benchmark information about a range of health‐related issues. Data were available from 17,033 men and 17,174 women, ≥20 years or age. BMI, based on self‐reported weight and height, was analyzed in relation to the use of medical services and preventive health services. Results: A positive relationship was found between BMI and medical service use, such as medication use, visits to hospital accident and emergency departments (for women only); doctor visits, visits to a hospital outpatient clinics; and visits to other health professionals (for women only). A negative relationship was found in women between BMI and preventive health services. Underweight women were found to be significantly less likely to have Papanicolaou smear tests, breast examinations, and mammograms. Discussion: This research shows that people who fall outside the healthy weight range are more likely to use a range of medical services. Given that the BMI of industrialized populations appears to be increasing, this has important ramifications for health service planning and reinforces the need for obesity prevention strategies at a population level.     

Association Between Prolactinoma and Body Mass Index

ObjectiveObesity is increasing worldwide, and certain endocrine disorders may contribute to weight gain. While several studies have examined the association between weight gain and prolactinomas, the results are conflicting. Therefore, this study aimed to determine if body mass index (BMI) is higher among those with prolactinomas than those without.MethodsWe identified patients ≥18 years of age referred to an endocrine clinic between 2008 and 2018 with newly diagnosed prolactinomas. We extracted the relevant information, and comparative data was obtained from the 2015-2016 National Health and Nutrition Examination Survey.ResultsIn total, 34 cases met the inclusion criteria. One third of the patients described weight gain at presentation. Those with prolactinomas had a significantly higher BMI than the National Health and Nutrition Examination Survey population (median BMI, 29.8 kg/m² vs 28.3 kg/m², P = .0048). When stratified by sex, only men with prolactinomas had an increased BMI compared with the controls. Moreover, those with prolactinomas had a higher prevalence of class II obesity (BMI ≥ 35 kg/m²) than the survey population (35% vs 18%, P = .01). Among the prolactinoma patients, a correlation was observed between BMI and log-transformed prolactin levels (R² = 0.4, P = .0002).ConclusionWeight gain can be a presenting symptom for patients with newly diagnosed prolactinomas. Those with prolactinomas have a higher BMI and an increased prevalence of class II obesity. These findings suggest that patients should be counseled regarding weight issues related to prolactinomas at presentation and should be a consideration in the investigative and treatment algorithm of prolactinomas.     

Maternal Gestational Diabetes Mellitus and Offspring Body Mass Index from 1 to 4 Years

ObjectiveUsing the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria to diagnose gestational diabetes mellitus (GDM), the association between GDM and offspring body mass index (BMI) gains in early childhood in China remains unclear. We aimed to assess the association between GDM diagnosed by the IADPSG criteria and BMI gain and the risk for overweight/obesity in offspring from 1 to 4 years.MethodsThis prospective cohort study was based on the healthcare records data from the Medical Birth Registry in Xiamen, China. We included 10,412 mother-child pairs tested for GDM using IADPSG criteria.ResultsA total of 1,786 (17.2%) offspring were exposed to GDM. The offspring exposed to GDM had higher mean BMI Z-score (difference, 0.07; 95% confidence interval [CI], 0.02 to 0.12) and risk for overweight/obesity (odds ratio [OR], 1.22; 95% CI, 1.06 to 1.40) compared to those unexposed to GDM from 1 to 4 years of age. However, after adjustment for maternal pre-pregnancy BMI (Model 2), these associations attenuated towards the null (difference in BMI Z-score, 0.02; 95% CI, -0.03 to 0.07; OR for overweight/obesity, 1.09; 95% CI, 0.95 to 1.25).ConclusionThe associations between GDM diagnosed using IADPSG criteria and BMI Z-score and the risk for overweight/obesity in offspring at the age of 1 to 4 years were largely explained by maternal pre-pregnancy BMI. Reducing the prevalence of childhood overweight and obesity in China should focus on maternal weight status before pregnancy, in addition to glycemia during pregnancy.     

Resemblance for Body Mass Index in Families of Obese African American and European American Women

Objective: We determined the levels of resemblance in body mass index (BMI) in large samples of families selected through obese African American and European American women. Research Methods and Procedures: We examined correlations among relatives in 1185 European American and African American families ascertained through age-matched obese women (BMI ≥ 30 kg/m²). A subset of 801 families were ascertained through extremely obese women (BMI ≥ 40 kg/m²). Results: Parent-offspring and sibling correlations ranged from 0.19 to 0.15, suggesting a moderate level of heritability in both groups. Mean BMI values for female relatives were lower for European Americans than for African Americans even though probands were matched, perhaps because the European American relatives regress to a lower population mean. We found significantly higher family correlations for height in European Americans, suggesting greater environmental variability among African Americans for factors affecting growth and physical development. Discussion: Our results suggest a similar level of heritability of BMI in families of obese African American and European American women. Other genetic studies will be needed to determine the extent to which the same or different genes and environmental conditions contribute to an overall similar heritability in the two racial groups.     

Body Size Perceptions and Eating Attitudes in Elderly Men

The majority of studies on eating attitudes, dieting and body size perceptions have focused on young adults and women. This study examined these attitudes in 334 black and white men, ages 55 to 98 years, who were members of the Charleston Heart Study cohort. Associations of the eating attitude variable with race, education and weight status were examined. Eighty-two percent of the overweight white men studied had dieted to lose weight, whereas only 49% of slimmer white men had dieted. In contrast, overweight black men did not diet more than slimmer black men. Overall black men dieted less than white men (37% reported dieting). Black men who were high school graduates were 1.3 times more likely to have dieted than were less educated black men. Overweight white men were over twice as likely as slimmer white men to feel guilty after overeating. This difference was not found in overweight versus slimmer black men. Education was not associated with measured body mass index (BMI) or perceived or ideal body size. However, there were some racial differences in these variables. White men preferred to be slightly thinner than black men (ideal BMI 25.6 vs. 26.1 kg/m²), and the difference between actual and desired BMI was 0.6 kg/m² greater in white than in black men. These results indicate that effects of race and weight status on eating restraint and body size perceptions seen in younger subjects and in women are also present, at least to some degree, in elderly men.     

Waist-to-Height Ratio Is More Predictive of Years of Life Lost than Body Mass Index

Objective

Our aim was to compare the effect of central obesity (measured by waist-to-height ratio, WHtR) and total obesity (measured by body mass index, BMI) on life expectancy expressed as years of life lost (YLL), using data on British adults.

Methods

A Cox proportional hazards model was applied to data from the prospective Health and Lifestyle Survey (HALS) and the cross sectional Health Survey for England (HSE). The number of years of life lost (YLL) at three ages (30, 50, 70 years) was found by comparing the life expectancies of obese lives with those of lives at optimum levels of BMI and WHtR.

Results

Mortality risk associated with BMI in the British HALS survey was similar to that found in US studies. However, WHtR was a better predictor of mortality risk. For the first time, YLL have been quantified for different values of WHtR. This has been done for both sexes separately and for three representative ages.

Conclusion

This study supports the simple message “Keep your waist circumference to less than half your height”. The use of WHtR in public health screening, with appropriate action, could help add years to life.     

Relationships Between the Body Mass Index and Body Composition

The aims of this study were to evaluate the Body Mass Index (BMI) (weight/stature²) as a proxy for percent body fat (%BF) and to determine its association with fat-free mass (FFM). Multivariate analysis of variance and partial correlations were used to examine relationships between BMI and %BF and FFM from densitometry for 504 men and 511 women, aged 20 to 45 years. Sensitivity/specificity analyses used cut offs of 28 kg/m² in men and 26 kg/m² in women for BMI, and 25% in men and 33% in women for %BF. Significantly higher associations existed in each gender between BMI and %BF in the upper BMI tertile than in the lower BMI tertiles. In the lower BMI tertiles, correlations between BMI and FFM were approximately twice as large as those between BMI and %BF. The BMI correctly identified about 44% of obese men, and 52% of obese women when obesity was determined from %BF. BMI is an uncertain diagnostic index of obesity. Results of Receiver Operator Characteristic (ROC) analyses using %BF and total body fat, both provided a BMI of 25 kg/m² in men and 23 kg/m² in women as diagnostic screening cut offs for obesity.     

Genetic Influences on Changes in Body Mass Index: A Longitudinal Analysis of Women Twins

AUSTIN, MELISSA A, YECHIEL FRIEDLANDER, BETH NEWMAN, KAREN EDWARDS, ELIZABETH J MAYER-DAVIS, MARY-CLAIRE KING. Genetic influences on changes in body mass index: a longitudinal analysis of women twins. Numerous studies have demonstrated genetic influences on body fat, but there also may be genetic effects on its intraindividual variation over time. This study examined changes in body mass index (BMI) using longitudinal data from two examinations of the Kaiser Permanente Women Twins Study, performed a decade apart. The analysis included 630 women, 185 monozygotic and 130 dizygotic twin pairs, with average ages of 41 years and 51 years at the two examinations, respectively. Age adjusted heritability estimates for the change in BMI over the decade ranged from 0.57 to 0.86 (all ρ≤0.001) using three different statistical analysis approaches, indicating that at least half, and possibly as much as 85%, of the variance in the change in BMI is attributable to genetic influences under a polygenic model. These estimates remained statistically significant after adjusting for environmental factors (ranging from 0.57 to 0.78) and with additional adjustment for BMI at baseline (ranging from 0.41 to 0.79), although dizygotic intraclass correlations were low after these adjustments. Thus, in addition to known environmental and behavioral influences, these results provide evidence for genetic influences on changes in BMI over a decade in women.     

The Relationship of Body Mass Index to Reproductive Factors in Pre- and Postmenopausal African-American Women With and Without Breast Cancer

To date, there are virtually no existing data on the relationship between obesity, menopausal status, and breast cancer in African-Americans. Therefore, the present study was designed to test the following hypotheses in an African-American population: (1) there exists a positive association between BMI and breast cancer among postmenopausal women; (2) there exists an inverse association between BMI and breast cancer among premenopausal women; and (3) similar associations between BMI and reproductive factors exist for both pre- and postmenopausal breast cancer cases. The study population comprised 357 African-American women (n=193 breast cancer cases; n=164 controls). No significant differences were observed between premenopausal cases and controls for BMI, obesity categories, and reproductive factors. Among the postmenopausal women, the cases had significantly lower weight and BMI levels than the controls. Age at first pregnancy and parity were significantly lower among postmenopausal cases than their controls. No significant associations were revealed between body mass index and breast cancer for pre- and postmenopausal women. In the present study, early age at menarche was the only reproductive factor that was an independent predictor of BMI for both pre- and postmenopausal women, irrespective of breast cancer status. Also, these findings strongly suggest the need to consider reproductive factors, particularly age at menarche, as a covariate of BMI and other obesity-related diseases.     

Meta-Analysis of the Effect of Excluding Early Deaths on the Estimated Relationship between Body Mass Index and Mortality

ALLISON, DAVID B., MYLES S. FAITH, MOONSEONG HEO, DIANA TOWNSEND-BUTTERWORTH, AND DAVID F. WILLIAMSON. Meta-analysis of the effect of excluding early deaths on the estimated relationship between body mass index and mortality. Obes Res. Objectives: Prospective cohort studies typically observe U-or J-shaped relationships between body mass index (BMI) (kg/m²) and mortality. However, some studies suggest that the elevated mortality at lower BMIs is due to confounding by pre-existing occult disease and recommend eliminating subjects who die during the first several (k) years of follow-up. This meta-analysis tests the effects of such early death exclusion on the BMI-mortality association. Research Methods and Procedures: Studies identified from MEDLINE, review articles, ancestry analyses, and the “invisible college.” Included studies: 1) measured relative body weight at baseline; 2) inchded at least 1000 subjects; 3) reported results with and without early-death exclusion, or relevant data; and 4) did not study exclusively diseased populations. Blank tables were mailed to 131 investigators covering 59 databases. Completed tables (n = 16 databases), electronic raw data (n = 7 databases), and original articles (n = 6 databases) provided final data. Meta-analytic regressions compared the BMI-mortality association with and without early death exclusion. The sample included 29 studies and 1,954,345 subjects. Results: The effect of eliminating early deaths was statistically significant but minuscule in magnitude. Implementation of early death exclusion was estimated to shift the BMI associated with minimum mortality only 0. 4 units for men and 0. 6 units for women at age 50. Even at a BMI 16, the estimated relative risk (compared to BMI 25) decreased only 0. 008 units for men and 0. 076 units for women at age 50. Discussion: Results indicate that either pre-existing disease does not confound the BMI—mortality association or eliminating early deaths is inefficient for reducing that confounding.     

Body Mass Index and Decline of Cognitive Function

Background

The association between body mass index (BMI) and cognitive function is a public health issue. This study investigated the relationship between obesity and cognitive impairment which was assessed by the Korean version of the Mini-mental state examination (K-MMSE) among mid- and old-aged people in South Korea.

Methods

A cohort of 5,125 adults, age 45 or older with normal cognitive function (K-MMSE≥24) at baseline (2006), was derived from the Korean Longitudinal Study of Aging (KLoSA) 2006~2012. The association between baseline BMI and risk of cognitive impairment was assessed using multiple logistic regression models. We also assessed baseline BMI and change of cognitive function over the 6-year follow-up using multiple linear regressions.

Results

During the follow-up, 358 cases of severe cognitive impairment were identified. Those with baseline BMI≥25 kg/m² than normal-weight (18.5≤BMI<23 kg/m²) were marginally less likely to experience the development of severe cognitive impairment (adjusted odds ratio [aOR] = 0.73, 95% CI = 0.52 to 1.03; P_trend = 0.03). This relationship was stronger among female (aOR = 0.63, 95% CI = 0.40 to 1.00; P_trend = 0.01) and participants with low-normal K-MMSE score (MMSE: 24–26) at baseline (aOR = 0.59, 95% CI = 0.35 to 0.98; P_trend<0.01). In addition, a slower decline of cognitive function was observed in obese individuals than those with normal weight, especially among women and those with low-normal K-MMSE score at baseline.

Conclusion

In this nationally representative study, we found that obesity was associated with lower risk of cognitive decline among mid- and old-age population.     

Association of a Body Mass Index Genetic Risk Score with Growth throughout Childhood and Adolescence

Background

While the number of established genetic variants associated with adult body mass index (BMI) is growing, the relationships between these variants and growth during childhood are yet to be fully characterised. We examined the association between validated adult BMI associated single nucleotide polymorphisms (SNPs) and growth trajectories across childhood. We investigated the timing of onset of the genetic effect and whether it was sex specific.

Methods

Children from the ALSPAC and Raine birth cohorts were used for analysis (n = 9,328). Genotype data from 32 adult BMI associated SNPs were investigated individually and as an allelic score. Linear mixed effects models with smoothing splines were used for longitudinal modelling of the growth parameters and measures of adiposity peak and rebound were derived.

Results

The allelic score was associated with BMI growth throughout childhood, explaining 0.58% of the total variance in BMI in females and 0.44% in males. The allelic score was associated with higher BMI at the adiposity peak (females  =  0.0163 kg/m² per allele, males  =  0.0123 kg/m² per allele) and earlier age (-0.0362 years per allele in males and females) and higher BMI (0.0332 kg/m² per allele in females and 0.0364 kg/m² per allele in males) at the adiposity rebound. No gene:sex interactions were detected for BMI growth.

Conclusions

This study suggests that known adult genetic determinants of BMI have observable effects on growth from early childhood, and is consistent with the hypothesis that genetic determinants of adult susceptibility to obesity act from early childhood and develop over the life course.