Gestational weight gain in relation to offspring obesity over the life course: a systematic review and bias‐adjusted meta‐analysis

Gestational weight gain (GWG) is considered one of the risk factors for future obesity in the offspring. However, the direction and strength of this association at different periods of offspring life is relatively unknown. This study investigates whether excess or inadequate maternal GWG during pregnancy influences the risk of offspring obesity at different stages in life. A systematic review of published articles was undertaken after a comprehensive search of different databases, and extracted data were meta‐analysed. To quantify offspring obesity estimates in relation to GWG, we stratified obesity estimates within three life stages of the offspring age: <5 years, 5 to <18 years and 18+ years. Our meta‐analysis showed that, compared with offspring of women with adequate GWG, offspring of women who gained inadequate gestational weight were at a decreased risk of obesity (relative risk [RR]: 0.86; 95% confidence interval [CI]: 0.78–0.94), and offspring of women who gained excess weight were at an increased risk of obesity (RR: 1.40; 95% CI: 1.23–1.59). These relationships were similar after stratification by life stage. Findings of this study therefore suggest that excess GWG does influence offspring obesity over the short‐ and long‐term, and should therefore be avoided.     

Healthy Life Trajectories Initiative: Summary of the evidence base for pregnancy‐related interventions to prevent overweight and obesity in children

This overview of systematic reviews (SRs) aimed to identify dietary and lifestyle interventions in pregnant women that reduce the prevalence of overweight, obesity, and/or risk factors thereof, in their children. Following identification of eligible SRs, a matrix of all included studies identified overlap between SRs. The most recent, comprehensive, high‐quality SRs were selected for further dissagregation. We developed a Grading of Recommendations, Assessment, Development and Evaluations (GRADE)‐based effectiveness matrix incorporating effect size and study quality to prioritise interventions as (1) beneficial or harmful, (2) possibly beneficial or possibly harmful, (3) no effect, (4) possibly no effect, or (5) uncertain effect. Of the 27 SRs identified, 16 SRs were excluded due to overlap. From 11 remaining SRs, five discrete interventions were ranked “beneficial” or “possibly beneficial” for reducing risk factors for childhood obesity: (1) balanced energy/protein supplements, (2) dietary counseling alone, (3) low glycemic index dietary advice, (4) diet and exercise counseling, (5) diet counseling and supervised exercise. High protein supplementation was ranked “harmful” as it increased the risk of small‐for‐gestational age (SGA) infants in normal‐weight pregnant women. Evidence of the impact of pregnancy‐related diet or lifestyle interventions, on childhood obesity was limited. Five dietary interventions, alone or in combination with exercise, showed beneficial effects on the risk factors for childhood obesity.     

Optimizing weight gain in pregnancy to prevent obesity in women and children

Pregnancy is now considered to be an important risk factor for new or persistent obesity among women during the childbearing years. High gestational weight gain is the strongest predictor of maternal overweight or obesity following pregnancy. A growing body of evidence also suggests that both high and low gestational weight gains are independently associated with an increased risk of childhood obesity, suggesting that influences occurring very early in life are contributing to obesity onset. In response to these data, the US Institute of Medicine (IOM) revised gestational weight gain guidelines in 2009 for the first time in nearly two decades. However, less than one third of pregnant women achieve guideline-recommended gains, with the majority gaining above IOM recommended levels. To date, interventions to optimize pregnancy weight gains have had mixed success. In this paper, we summarize the evidence from human and animal studies linking over-nutrition and under-nutrition in pregnancy to maternal and child obesity. In addition, we discuss published trials and ongoing interventions to achieve appropriate gestational weight gain as a strategy for obesity prevention in women and their children.     

Mechanisms linking obesity,inflammation and altered metabolism to colon carcinogenesis

Due to its prevalence, obesity is now considered a global epidemic. It is linked to increased risk of colorectal cancer, the third most common cancer and the second leading cause of death among adults in Western countries. Obese adipose tissue differs from lean adipose tissue in its immunogenic profile, body fat distribution and metabolic profile. Obese adipose tissue releases free fatty acids, adipokines and many pro‐inflammatory chemokines. These factors are known to play a key role in regulating malignant transformation and cancer progression. Obese adipose tissue is infiltrated by macrophages that participate in inflammatory pathways activated within the tissue. Adipose tissue macrophages consist of two different phenotypes. M1 macrophages reside in obese adipose tissue and produce pro‐inflammatory cytokines, and M2 macrophages reside in lean adipose tissue and produce anti‐inflammatory cytokines, such as interleukin‐10 (IL‐10). The metabolic networks that confer tumour cells with their oncogenic properties, such as increased proliferation and the ability to avoid apoptosis are still not well understood. We review the interactions between adipocytes and immune cells that may alter the metabolism towards promotion of colorectal cancer.     

Gut microbiota and obesity: An opportunity to alter obesity through faecal microbiota transplant (FMT)

Obesity is a global pandemic with immense health consequences for individuals and societies. Multiple factors, including environmental influences and genetic predispositions, are known to affect the development of obesity. Despite an increasing understanding of the factors driving the obesity epidemic, therapeutic interventions to prevent or reverse obesity are limited in their impact. Manipulation of the human gut microbiome provides a new potential therapeutic approach in the fight against obesity. Specific gut bacteria and their metabolites are known to affect host metabolism and feeding behaviour, and dysbiosis of this biosystem may lead to metabolic syndrome. Potential therapies to alter the gut microbiota to treat obesity include dietary changes, supplementation of the diet with probiotic organisms and prebiotic compounds that influence bacterial growth, and the use of faecal microbiota transplant, in which gut microbiota from healthy individuals are introduced into the gut. In this review, we examine the growing scientific evidence supporting the mechanisms by which the human gut microbiota may influence carbohydrate metabolism and obesity, and the various possible therapies that may utilize the gut microbiota to help correct metabolic dysfunction.     

Effects of childhood abuse on adult obesity: a systematic review and meta‐analysis

Controversy exists surrounding the role of childhood abuse in obesity development. This is a meta‐analysis of observational studies on the role of childhood abuse in adult obesity. Systematic searches of PubMed, PsycInfo, Medline and CINAHL resulted in 23 cohort studies (4 prospective, 19 retrospective) with n = 112,708 participants, containing four abuse types (physical, emotional, sexual, general). Four studies reported dose–response effects. A random effects model was used to quantify effect sizes, meta‐regression/subgroup analysis for identifying potential moderating variables and Egger's test for publication bias. Adults who reported childhood abuse were significantly more likely to be obese (odds ratio [OR]: 1.34, 95% confidence interval [CI]: 1.24–1.45, P < 0.001). All four types of abuse were significantly associated with adult obesity: physical (OR: 1.28, 95% CI: 1.13–1.46), emotional (OR: 1.36, 95% CI: 1.08–1.71), sexual (OR: 1.31, 95% CI: 1.13–1.53) and general abuse (OR: 1.45, 95% CI: 1.25–1.69). Severe abuse (OR: 1.50, 95% CI: 1.27–1.77) was significantly more associated with adult obesity (P = 0.043) compared with light/moderate abuse (OR: 1.13, 95% CI: 0.91–1.41). We found no significant effects of study design (prospective vs. retrospective, P = 0.07), age (P = 0.96) or gender (P = 0.92). Publication bias was evident (Egger's test P = 0.007), but effect sizes remained statistically significant in sensitivity analyses. Childhood abuse was clearly associated with being obese as an adult, including a positive dose–response association. This suggests that adverse life experiences during childhood plays a major role in obesity development, potentially by inducing mental and emotional perturbations, maladaptive coping responses, stress, inflammation and metabolic disturbances.     

Offspring birth weight,gestational age and maternal characteristics in relation to glucose status at age 53 years: evidence from a national birth cohort

Aims We investigated pathways linking offspring birth weight to maternal diabetes risk in later life by taking into account a range of prospective early-life and adult maternal factors. Methods In a national birth cohort study, we examined the relationship between offspring birth weight and maternal glycated haemoglobin (HbA_1c) at age 53 years in 581 mothers who had a first birth between age 19 and 25 years, and had data on potential confounders or mediators. Results Mean age at first birth was 21.5 years. After adjustment for maternal body mass index (BMI), mean percentage change in maternal HbA_1c per kilogram increase in offspring birth weight was −1.8%[95% confidence interval (CI) −3.5, −0.1; P = 0.03]. This relationship was mostly accounted for by gestational age that was inversely related to maternal HbA_1c (−0.9%; 95% CI −1.5, −0.4; P = 0.001). Other risk factors for high HbA_1c were smoking and high BMI at 53 years. There was a significant interaction between offspring birth weight and maternal childhood social class (P = 0.01). Mothers from a manual background with higher birth weight offspring had lower HbA_1c (BMI adjusted: −3.1%; 95% CI −5.0, −1.1); this was not observed for mothers from a non-manual background (BMI adjusted: 1.9%; 95% CI −1.3, 5.0). Conclusions Short gestational age and low offspring birth weight may be part of a pathway linking impaired early maternal growth to diabetes risk in later life. A second possible pathway linking higher offspring birth weight to later maternal glucose status was also identified. These potential pathways require further investigation in cohorts with a wider maternal age range so that the early targeting of public health initiatives can be assessed.     

Fast food consumption and increased caloric intake: a systematic review of a trajectory towards weight gain and obesity risk

Consumption of fast food, which have high energy densities and glycemic loads, and expose customers to excessive portion sizes, may be greatly contributing to and escalating the rates of overweight and obesity in the USA. Whether an association exists between fast food consumption and weight gain is unclear. Sixteen studies (six cross sectional, seven prospective cohort, three experimental) meeting methodological and relevance criteria were selected for inclusion in this systematic review. While more research needs to be conducted specifically in regard to effects of fast food consumption among subpopulations such as children and adolescents, sufficient evidence exists for public health recommendations to limit fast food consumption and facilitate healthier menu selection. As the fast food industry continues to increase both domestically and abroad, the scientific findings and corresponding public health implications of the association between fast food consumption and weight are critical.     

Eating behaviors in relation to gestational weight gain and postpartum weight retention: A systematic review

Preventing obesity is of utmost public health importance. This paper systematically reviews associations between eating behaviors and peripartum weight change. This knowledge is crucial in the development of interventions that reduce long‐term obesity, often triggered and boosted in the peripartum. Through MEDLINE, EMBASE, and Web of Science, we identified 20 studies that fulfilled inclusion criteria: studies on food cravings, disinhibition, restrained, external, emotional, uncontrolled, intuitive, or mindful eating in relation to gestational or postpartum weight among adult women. Higher gestational weight gain was associated with lower intuitive eating (in 3/3 studies) and higher restrained eating (in 4/11 studies), external eating (in 2/2 studies), emotional eating (in 3/4 studies), food cravings (in 3/3 studies), and disinhibition (in 1/3 studies). No association with uncontrolled eating was found (in one study). No studies on mindful eating and gestational weight were identified. Higher postpartum weight loss was associated with higher restrained (in 2/4 studies) and intuitive eating (in 1/1 study). No associations between postpartum weight and food cravings, disinhibition, and mindful eating were found. No studies on external, emotional and uncontrolled eating, and postpartum weight were identified. Concluding, certain eating behaviors might be related to peripartum weight change.     

The role of maternal obesity in infant outcomes in polycystic ovary syndrome—A systematic review,meta‐analysis,and meta‐regression

Polycystic ovary syndrome (PCOS) is associated with worsened pregnancy and infant outcomes, higher body mass index (BMI), and longitudinal weight gain. Despite most of the clinical features of PCOS being risk factors for worsened infant outcomes in the general population, their impact on infant outcomes in PCOS is unknown. We aimed to investigate the association of PCOS with infant outcomes considering maternal adiposity, other known risk factors, and potential confounders. The meta‐analyses included 42 studies in 7041 women with PCOS and 63 722 women without PCOS. PCOS was associated with higher gestational weight gain (GWG) and with higher preterm birth and large for gestational age and with lower birth weight with this association varying by geographic continent, PCOS phenotypes, and study quality. However, PCOS was associated with none of these outcomes on BMI‐matched studies. Gestational diabetes was significantly associated with an increased preterm birth on meta‐regression. We report for the first time that GWG is higher in PCOS. Infant outcomes vary by geographic continent and study quality but are similar in BMI‐matched women with and without PCOS. This suggests that infant outcomes in PCOS may be related to maternal obesity. These novel findings warrant future studies in PCOS investigating screening and management of infant outcomes with consideration of maternal obesity.     

Preterm birth and low birth weight continue to increase the risk of asthma from age 7 to 43

Background: Perinatal events can influence the development of asthma in childhood but current evidence is contradictory concerning the effects on life-time asthma risk. Objective: To assess the relationship between birth characteristics and asthma from childhood to adulthood. Methodology: All available birth records for the Tasmanian Longitudinal Health Study (TAHS) cohort, born in 1961 were obtained from the Tasmanian State Archives and Tasmanian hospitals. Low birth weight (LBW) was defined as less than 2500 grams. Preterm birth was defined as delivery before 37 weeks' gestation. Small for gestational age (SGA) was defined as a birth weight below the 10^th percentile for a given gestational age. Multivariate logistic and cox regression were used to examine associations between birth characteristics and lifetime risk of current and incident asthma, adjusting for confounders. Results: The prevalence of LBW was 5.2%, SGA was 13.8% and preterm was 3.3%. LBW (OR = 1.65, 95%CI 1.12,2.44) and preterm birth (OR = 1.81, 95%CI 0.99, 3.31) were both associated with an increased risk of current asthma between the ages of 7 to 43 years. There was no association between SGA and current asthma risk. However, SGA was associated with incident asthma (HR = 1.32, 95%CI 1.00, 1.74), and there was an interaction with sex (p value = 0.08), with males having a greater risk of incident asthma (HR = 1.70, 95%CI 1.16–2.49) than females (HR = 1.04, 95%CI 0.70–1.54). Conclusions: Preterm birth and LBW were associated with an increased risk of current asthma into middle-age. These findings are the first to demonstrate the continuing impact of these characteristics on asthma risk into middle-age.     

Determining optimal gestational weight gain (GWG) in a northwest Chinese population: A CONSORT

To determine optimal gestational weight gain (GWG) for the Chinese population.Live singleton deliveries at the largest maternal & childcare hospital in northwest China from 2010 to 2012 were analyzed retrospectively. Multivariable logistic regression analysis was conducted to determine the lowest aggregated risk of interested perinatal outcomes based on Chinese adult body mass index (BMI) categories.Eight thousand eight hundred seventy enrolled parturients were divided into 4 groups according to their prepregnancy BMI: underweight (21.31%, BMI < 18.5 kg/m²), normal weight (67.81%, 18.5 kg/m² ≤ BMI < 24 kg/m²), overweight (8.99%, 24 kg/m² ≤ BMI < 28 kg/m² and obese (1.89%, BMI ≥ 28 kg/m²). The optimal GWG values for the above 4 groups were 16.7 kg (GWG range, 12.0–21.5), 14.5 kg (9.5–19.5), 11.5 kg (7.0–16.5), and 8.0 kg (5.0–13.0). The rates of inadequate, optimal and excessive GWG in present study were 6.14% (545), 62.34% (5529), and 31.52% (2796) respectively, which were significantly different from those of the 2009 Institute of Medicine recommendation (χ² = 1416.05, Pinteraction < 0.0001).Wider optimal GWG ranges than those recommended by Institute of Medicine were found in our study, and our proposed criteria seems to be practical to the Chinese population.     

Insulin release in response to oral glucose in obesity: The effect of reduction of body weight

Summary Measurements of plasma levels of immunoreactive insulin, non-esterified fatty acids and glucose have been made in normal subjects and a group of obese non diabetic patients, before and after a period of dietary restriction. Levels of immuno-reactive insulin, both in the fasted state and after an oral glucose load, were abnormally high in the group of obese patients and were significantly lower after dietary restriction and loss of body weight.

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Insulinfreisetzung unter oraler Glucosebelastung bei Fettsucht: Einfluß der Gewichtsabnahme

Zusammenfassung Es wurden Messungen der Plasma spiegel von immunreaktivem Insulin, unveresterten Fett-säuren und Glucose bei normalen Personen und bei einer Gruppe von fettleibigen Nichtdiabetikern vor sowie nach einer Periode der Diätbeschränkung vorgenommen. Die Konzentration des immunreaktiven Insulins lag bei den fettleibigen Patienten sowohl im Nüchternzustand als auch nach einer oralen Glucosebelastung abnorm hoch und ging nach Diätbeschränkung und Gewichtsverlust wesentlich zurück.

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Libération d'insuline en réponse à l'administration orale de glucose dans l'obésité: Effet de la réduction du poids corporel

Résumé La concentration plasmatique d'insuline immuno-réactive, d'acides gras non estérifiés et de glucose a été déterminée chez des sujets normaux et dans un groupe d'obèses non diabétiques avant et après une période de restriction alimentaire. La concentration d'insuline immuno-réactive à jeun et après administration orale de glucose était anormalement élevée dans le groupe des sujets obèses et montra une diminution significative après une période de restriction alimentaire ayant entraîné une perte de poids.

     

Objectively measured physical activity and obesity prevention in children,adolescents and adults: a systematic review of prospective studies

This study aimed at synthesizing the prospective associations between measured physical activity (PA) and change in adiposity in children, adolescents and adults following from two previous reviews. Search terms were adapted and a systematic literature search was conducted (January 2000–September 2008) and later updated (up to October 2009), considering observational and intervention studies of weight gain that measured both PA and body composition. Sixteen observational studies (six comprising adults) and five trials (one comprising adults) were eligible. For consistency, whenever possible either baseline PA energy expenditure or accelerometer output (counts min^?1) and change in per cent body fat were the extracted exposure and outcome measures. Results of observational studies suggest that PA is not strongly prospectively related with adiposity: five studies on children and three on adults reported no association between baseline PA and change in adiposity, one study found a weak positive association and the other studies observed a weak negative association. Negative associations were more frequently observed in studies that analysed the association between change in the exposure and outcome. Intervention studies show generally no effect on either PA or adiposity. In conclusion, despite the well‐established health benefits of PA, it may not be a key determinant of excessive gain in adiposity.     

Relation of maternal blood pressure during pregnancy to birth weight and blood pressure in children. The Hypertension in Pregnancy Offspring Study

Objective . To evaluate the importance of perinatal factors, e.g. low birth weight, reduced gestational period and elevated maternal blood pressure during pregnancy, as well as high maternal blood pressure at follow-up 7–12 years after pregnancy, on blood pressure in children born after normotensive and hypertensive pregnancies. Design . Follow-up study in children from hypertensive pregnancies and a control group of children born after normotensive pregnancies. Setting . University Hospital, Göteborg, Sweden. Subjects . Thirty-six children born after hypertensive pregnancies and a control group of 17 children born after normotensive pregnancies were studied at a mean age of 12.5 years. Main outcome measure . Blood pressure. Results . Systolic blood pressure was higher in children born after hypertensive pregnancies. They also had lower birth weight and a shorter gestational period. There was a negative correlation between the highest recorded maternal blood pressure during pregnancy and birth weight of the child and a positive correlation between maternal blood pressure and blood pressure in their offspring. No correlation was found between birth weight and blood pressure in these children. Conclusions . Children born after hypertensive pregnancies have higher blood pressure compared to children born after normotensive pregnancies. There is a positive relationship between childhood blood pressure and maternal blood pressure during pregnancy.     

Physical activity and obesity: what we know and what we need to know*

Creating a negative energy balance by decreasing caloric consumption and increasing physical activity is a common strategy used to treat obesity. A large number of review and original research papers have considered the role of physical activity in weight loss and maintenance. However, their conclusions are at times conflicting. In this review, we have critically evaluated the findings of systematic reviews and meta‐analyses and supplemented their conclusions with recently published, high‐quality clinical trials. We have eliminated studies that were methodologically flawed in an attempt to reduce the ambiguity in the literature. We further sought, through selective review of these publications, to isolate the effects of various types of exercise, independent of dietary interventions, to further clarify their independent contributions. Thus, our review describes (i) combined calorie restriction with physical activity interventions, (ii) physical activity interventions without calorie restriction and (iii) the role of physical activity on maintenance of weight loss. Through this critical examination of the literature, we have provided conclusions to address certain ambiguities regarding the role of physical activity in obesity treatment that will inform clinical practice. We have also identified several long‐standing gaps in knowledge that will inform future research.