Changes in abdominal obesity and age-related macular degeneration: the atherosclerosis risk in communities study

OBJECTIVE: To examine the association between changes in waist-hip ratio (WHR), a measure of abdominal obesity, and age-related macular degeneration (AMD). METHODS: A total of 12 515 persons from a population-based cohort study, aged 45 to 64 years in 1987 to 1989, were followed up over 6 years. The percentage change in WHR during follow-up was ranked into sex-specific deciles; an increase in WHR was defined as the top 10% of change and a decrease in WHR as the bottom 10%. The association of increased or decreased WHR and presence of AMD at follow-up was determined using logistic regression adjusting for potential confounders. RESULTS: The average change in WHR was an increase of 2%, ranging from a decrease of 44% to an increase of 102%. A decrease in WHR of 3% or more was associated with 29% lower odds of any AMD (odds ratio = 0.71; 95% confidence interval, 0.52-0.97). This effect was most pronounced among obese participants at baseline, where a decrease in WHR was associated with 59% lower odds of AMD (odds ratio = 0.41; 95% confidence interval, 0.20-0.82). CONCLUSIONS: Middle-aged persons who had a 3% or greater reduction in WHR over time were less likely to have AMD, particularly among those who were initially obese.

The magnitude of association between overweight and obesity and the risk of diabetes: a meta-analysis of prospective cohort studies

The objectives of this meta-analysis were to examine the magnitude of the relative risk (RR) of developing type 2 diabetes for overweight and obese populations, compared to those with normal weight, and to determine causes of the variation in RR between various cohort studies. The magnitude of the RR was analyzed by combining 18 prospective cohort studies that matched defined criteria. The variance in RR between studies was explored. The overall RR of diabetes for obese persons compared to those with normal weight was 7.19, 95% CI: 5.74, 9.00 and for overweight was 2.99, 95% CI: 2.42, 3.72. The variation in RR among studies was explored and it was found that the effect of heterogeneity was highly related with sample size, method of assessment of body mass index (BMI) and method of ascertainment of type 2 diabetes. By combining only cohort studies with more than 400 cases of incident diabetes (>median), adjusted by at least three main confounding variables (age, family history of type 2 diabetes, physical activity), measured BMI, and diabetes determined by clinical diagnosis, the RR was 7.28, 95% CI: 6.47, 8.28 for obesity and 2.92, 95% CI: 2.57, 3.32 for overweight.

Conceptos y prácticas de la actividad física que se reproducen en las clases sociales: aproximación desde el enfoque determinantes/ determinación social de la salud

El concepto de actividad física es concebido de diferentes formas. Mostrando que existen varios factores que afectan de manera directa e indirecta la percepción que los sujetos construyen entorno a él, generando así una aproximación a diferentes definiciones de la actividad física desde varias perspectivas y dimensiones, donde predomina una noción netamente biológica. Este estudio pretende analizar, como desde las clases sociales se concibe la actividad física en sus conceptos y prácticas considerando los modelos de determinantes y determinación social para la salud. Con fin de comprender como los autores de la literatura científica conciben la actividad física y la relación con las clases sociales, desde una perspectiva teórica de los determinantes sociales de la salud y la teoría de la determinación social, se realizó una revisión documental y análisis de contenido de los conceptos y prácticas de la actividad física que se han considerado en los últimos 10 años. Para ello se seleccionaron las bases de datos PubMed y BVS (Biblioteca Virtual de Salud) por sus énfasis en publicaciones de salud mundialmente. Mostrando que la actividad física es concebida dominantemente desde una perspectiva biológica que ejerce una mirada reduccionista. Las relaciones entre actividad física y las clases sociales están claramente establecidas, sin embargo, estas relaciones pueden discrepar teniendo en cuenta el concepto de clase social, el contexto y la orientación de los autores y las poblaciones objetos de estudio. Obteniendo como resultado que los estudios documentados, revisados y analizados muestran una clara tendencia al modelo de determinantes; no obstante, algunos estudios en sus análisis se orientan hacia el modelo de determinación social. En cuanto al concepto de clases sociales los autores consideran una combinación de factores culturales y económicos sin atreverse a adoptar un concepto específico.

Trabajo nocturno e índice de masa corporal en los trabajadores de la salud : una revisión de la literatura

Introducción: Se considera el trabajo rotativo nocturno como aquel que se lleva a cabo fuera de las horas laborales diurnas. Se ha planteado que el trabajo en horas nocturnas podría estar relacionado con diversos desordenes, dentro de ellos un incremento en el índice de masa corporal con el consecuente desarrollo de sobrepeso y obesidad. El objetivo de este estudio es realizar una revisión de la literatura existente, acerca del trabajo rotativo nocturno y su relación con el índice de masa corporal (IMC) en trabajadores de la salud. Métodos: Se realizó una revisión sistemática de información publicada en los últimos 10 años en la base de datos PUBMED y se seleccionaron únicamente los artículos de texto completo relacionados con este tema en los idiomas inglés, español e italiano. Resultados: A través de la búsqueda se encontraron 10 artículos que cumplieron los criterios de inclusión definidos. Predominantemente se obtuvieron estudios de diseño transversal. Tres de estos estudios encontraron una asociación entre trabajo rotativo nocturno actual e incremento en el IMC y por el contrario dos estudios no hallaron esta asociación. Por otro lado, seis estudios coinciden en una asociación positiva entre mayor tiempo acumulado en trabajo rotativo nocturno y un incremento en el IMC. Conclusiones: Los hallazgos encontrados en los estudios analizados apuntan a la existencia de una estrecha relación entre el aumento del Índice de Masa Corporal (IMC) con los turnos nocturnos (o rotativos que incluyen este horario) llevados a cabo de manera prolongada, en los trabajadores de la salud, en comparación con los trabajadores que realizan turnos diurnos regulares.

Effect of a Web-Based Behavior Change Program on Weight Loss and Cardiovascular Risk Factors in Overweight and Obese Adults at High Risk of Developing Cardiovascular Disease:Randomized Controlled Trial

BACKGROUND: Web-based programs are a potential medium for supporting weight loss because of their accessibility and wide reach. Research is warranted to determine the shorter- and longer-term effects of these programs in relation to weight loss and other health outcomes.

OBJECTIVE: The aim was to evaluate the effects of a Web-based component of a weight loss service (Imperative Health) in an overweight/obese population at risk of cardiovascular disease (CVD) using a randomized controlled design and a true control group.

METHODS: A total of 65 overweight/obese adults at high risk of CVD were randomly allocated to 1 of 2 groups. Group 1 (n=32) was provided with the Web-based program, which supported positive dietary and physical activity changes and assisted in managing weight. Group 2 continued with their usual self-care (n=33). Assessments were conducted face-to-face. The primary outcome was between-group change in weight at 3 months. Secondary outcomes included between-group change in anthropometric measurements, blood pressure, lipid measurements, physical activity, and energy intake at 3, 6, and 12 months. Interviews were conducted to explore participants' views of the Web-based program.

RESULTS: Retention rates for the intervention and control groups at 3 months were 78% (25/32) vs 97% (32/33), at 6 months were 66% (21/32) vs 94% (31/33), and at 12 months were 53% (17/32) vs 88% (29/33). Intention-to-treat analysis, using baseline observation carried forward imputation method, revealed that the intervention group lost more weight relative to the control group at 3 months (mean -3.41, 95% CI -4.70 to -2.13 kg vs mean -0.52, 95% CI -1.55 to 0.52 kg, P<.001), at 6 months (mean -3.47, 95% CI -4.95 to -1.98 kg vs mean -0.81, 95% CI -2.23 to 0.61 kg, P=.02), but not at 12 months (mean -2.38, 95% CI -3.48 to -0.97 kg vs mean -1.80, 95% CI -3.15 to -0.44 kg, P=.77). More intervention group participants lost ≥5% of their baseline body weight at 3 months (34%, 11/32 vs 3%, 1/33, P<.001) and 6 months (41%, 13/32 vs 18%, 6/33, P=.047), but not at 12 months (22%, 7/32 vs 21%, 7/33, P=.95) versus control group. The intervention group showed improvements in total cholesterol, triglycerides, and adopted more positive dietary and physical activity behaviors for up to 3 months verus control; however, these improvements were not sustained.

CONCLUSIONS: Although the intervention group had high attrition levels, this study provides evidence that this Web-based program can be used to initiate clinically relevant weight loss and lower CVD risk up to 3-6 months based on the proportion of intervention group participants losing ≥5% of their body weight versus control group. It also highlights a need for augmenting Web-based programs with further interventions, such as in-person support to enhance engagement and maintain these changes.

Body image, strategies to change muscles and weight, and puberty. Do they impact on positive and negative affect among adolescent boys and girls?

The purpose of this study was to examine the impact of strategies to both decrease weight and increase muscle tone on negative (depression, anxiety) and positive affect among adolescent males and females. The respondents were 1185 adolescents (587 males, 598 females) who were enrolled in grades 7 and 9 (mean age for MALES=13.22 years; mean age for FEMALES=13.21 years). Respondents completed the Body Image and Body Change Inventory that assessed body image satisfaction, body image importance, body change strategies to decrease weight, body change strategies to increase muscle tone, and food supplements. Respondents also completed the Pubertal Development Scale, the depression and anxiety scales of the Depression Anxiety and Stress Scale, and the positive affect items from the Positive and Negative Affect Scale. Structural equation modelling was used to determine how body satisfaction and importance, body change strategies, and puberty impacted on depression, anxiety, and positive affect. The results demonstrated that for both boys and girls, there was a strong association between body change strategies and negative affect. For boys, body dissatisfaction did not predict negative affect, although this was a strong predictor for girls. Body change strategies did not strongly predict positive affect for either boys or girls, although body image satisfaction was a strong predictor for both genders. The implications of these findings for obtaining a better understanding of the role of pubertal development, body image, and body change strategies in predicting positive and negative affect among adolescent males and females are discussed.

Blood pressure change with weight loss is affected by diet type in men

Background: Weight loss reduces blood pressure, and the Dietary Approaches to Stop Hypertension (DASH) diet has also been shown to lower blood pressure.

Objective: Our goal was to assess the effect on blood pressure of 2 weight-reduction diets: a low-fat diet (LF diet) and a moderate-sodium, high-potassium, high-calcium, low-fat DASH diet (WELL diet).

Design: After baseline measurements, 63 men were randomly assigned to either the WELL or the LF diet for 12 wk, and both diet groups undertook 0.5 h of moderate physical activity on most days of the week.

Results: Fifty-four men completed the study. Their mean (±SD) age was 47.9 ± 9.3 y (WELL diet, n = 27; LF diet, n = 27), and their mean baseline home systolic and diastolic blood pressures were 129.4 ± 11.3 and 80.6 ± 8.6 mm Hg, respectively. Body weight decreased by 4.9 ± 0.6 kg (±SEM) in the WELL group and by 4.6 ± 0.6 kg in the LF group (P < 0.001 for both). There was a greater decrease in blood pressure in the WELL group than in the LF group [between-group difference (week 12 –baseline) in both SBP (5.5 ± 1.9 mm Hg; P = 0.006) and DBP (4.4 ± 1.2 mm Hg; P = 0.001)].

Conclusions: For a comparable 5-kg weight loss, a diet high in low-fat dairy products, vegetables, and fruit (the WELL diet) resulted in a greater decrease in blood pressure than did the LF diet. This dietary approach to achieving weight reduction may confer an additional benefit in reducing blood pressure in those who are overweight.

A longitudinal study to explain stratiges to change weight and muscles among normal weight and overweight children

Previous research has indicated that both boys and girls strive for a slim body, with boys having an additional focus on a muscular body build. The current study was designed to evaluate the utility of a biopsychosocial model to explain body image and body change strategies among children. The study evaluated changes over time in body image and strategies to lose weight and increase muscles among 132 normal weight and 67 overweight boys (mean age=9.23 years) and 158 normal weight and 55 overweight girls (mean age=9.33 years). The predictive role of BMI, positive and negative affect, self-esteem and perceived sociocultural pressures to lose weight or increase muscle on body image and body change strategies over a 16 month period was evaluated. All participants completed the questionnaire on both occasions. The results demonstrated that both overweight boys and girls were more likely to be dissatisfied with their weight, place more importance on their weight, engage in more strategies to lose weight as well as perceive more pressure to lose weight. Overweight boys and girls were also more likely to report lower levels of self-esteem and positive affect, and higher levels of negative affect, and reported a reduction in their self-esteem over time. Regression analyses demonstrated that among overweight boys, low self-esteem and high levels of perceived pressure to lose weight predicted weight dissatisfaction; for overweight girls, weight dissatisfaction was also predicted by low levels of self-esteem. The implication of these findings in terms of factors contributing to the adoption of health risk behaviors among children is discussed.

Weight, physical activity and dietary behavior change in young mothers : short term results of the HeLP-her cluster randomized controlled trial

Background
Preventing weight gain rather than treating established obesity is an important economic and public health response to the rapidly increasing rates of obesity worldwide. Treatment of established obesity is complex and costly requiring multiple resources. Preventing weight gain potentially requires fewer resources to reach broad population groups, yet there is little evidence for successful interventions to prevent weight gain in the community. Women with children are an important target group because of high rates of weight gain and the potential to influence the health behaviors in family members.

Methods
The aim of this cluster randomized controlled trial was to evaluate the short term effect of a community-based self-management intervention to prevent weight gain. Two hundred and fifty mothers of young children (mean age 40 years ± 4.5, BMI 27.9 kg/m2 ± 5.6) were recruited from the community in Melbourne, Australia. The intervention group (n = 127) attended four interactive group sessions over 4 months, held in 12 local primary schools in 2006, and was compared to a group (n = 123) receiving a single, non-interactive, health education session. Data collection included self-reported weight (both groups), measured weight (intervention only), self-efficacy, dietary intake and physical activity.

Results
Mean measured weight decreased significantly in the intervention group (-0.78 kg 95% CI; -1.22 to -0.34, p < 0.001). Comparing groups using self-reported weight, both the intervention and comparison groups decreased weight, -0.75 kg (95% CI; -1.57 to 0.07, p = 0.07) and -0.72 kg (95% CI; -1.59 to 0.14 p = 0.10) respectively with no significant difference between groups (-0.03 kg, 95% CI; -1.32 to 1.26, p = 0.95). More women lost or maintained weight in the intervention group. The intervention group tended to have the greatest effect in those who were overweight at baseline and in those who weighed themselves regularly. Intervention women who rarely self-weighed gained weight (+0.07 kg) and regular self-weighers lost weight (-1.66 kg) a difference of -1.73 kg (95% CI; -3.35 to -0.11 p = 0.04). The intervention reported increased physical activity although the difference between groups did not reach significance. Both groups reported replacing high fat foods with low fat alternatives and self-efficacy deteriorated in the comparison group only.

Conclusion
Both a single health education session and interactive behavioral intervention will result in a similar weight loss in the short term, although more participants in the interactive intervention lost or maintained weight. There were small non-significant changes to physical activity and changes to fat intake specifically replacing high fat foods with low fat alternatives such as fruit and vegetables. Self-monitoring appears to enhance weight loss when part of an intervention.

Motivation, readiness to change, and weight loss following adjustable gastric band surgery

High levels of readiness to change (RTC) are considered critical to the long-term success of weight management programs including bariatric surgery. However, there are no data to support this assertion. We hypothesize that RTC level will not influence weight outcomes following surgery. In 227 consecutive patients undergoing adjustable gastric banding surgery, we recorded reasons for seeking surgery, and RTC measured with the University of Rhode Island Change Assessment. Scores were blinded until study completion. The primary outcome measure was percentage of excess BMI loss at 2 years (%EBMIL-2); others included compliance and surgical complications. Of 227 subjects, 204 (90%) had weight measurement at 2 years. There was no significant correlation between RTC score and %EBMIL-2 (r = 0.047, P = 0.5). Using the median split for RTC score the lowest 102 subjects mean %EBMIL-2 was 52.9 ± 26.9% and the highest 52.2 ± 28.3%, P = 0.869. There was no weight loss difference between highest and lowest quartiles, or a nonlinear relationship between weight loss and RTC score. There was no significant relationship between RCT score and compliance, or likelihood of complications. Those motivated by appearance were more likely to be younger women who lost more weight at 2 years. Poor attendance at follow-up visits was associated with less weight loss, especially in men. Measures of RTC did not predict weight loss, compliance, or surgical complications. Caution is advised when using assessments of RTC to predict outcomes of bariatric surgery.

Excessive gestational weight gain: a psychosocial and behaviour change approach

Briony’s findings indicate that gaining excess weight during pregnancy can be influenced by depressive symptoms, body image, confidence, and motivation. Prevention of excessive pregnancy weight gain needs to be addressed by identifying women at risk and incorporating psychological and behaviour change intervention into broader health system and prevention programs.

Weight perception in overweight adolescents: Associations with body change intentions, diet and physical activity

This study examined the association of weight perception and weight satisfaction with body change intentions and weight-related behaviours in 928 overweight adolescents (aged 11-18 years, 44% female). Accurate perception of weight was associated with trying to lose weight and inaccurate perception was associated with trying to gain muscle. Weight dissatisfaction was associated with trying to lose weight and gain muscle. Accurate weight perception and weight dissatisfaction were not associated with healthy weight-related behaviours. Awareness of overweight and body dissatisfaction may be detrimental to the adoption of healthy weight-control behaviours. Interventions with overweight adolescents should encourage body satisfaction, rather than promoting awareness of overweight.

A path model of psychosocial and health behaviour change predictors of excessive gestational weight gain

This study aimed to evaluate a conceptual model of psychosocial, behaviour change, and behavioural predictors of excessive gestational weight gain (GWG). Background: Excessive GWG can place women and their babies at risk of poor health outcomes, including obesity. Models of psychosocial and behaviour change predictors of excessive GWG have not been extensively explored; understanding the mechanisms leading to excess GWG will provide crucial evidence towards the development of effective interventions. Method: Two hundred and eighty-eight pregnant women (≤18 weeks gestation) were recruited to a prospective study. Demographic, psychosocial, health behaviour change, and behavioural factors were assessed at 17 (Time 1, T1) and 33 weeks (Time 2, T2) gestation. Pre-pregnancy and final pregnancy weight were obtained and women were classified with/without excessive GWG. Logistic regressions refined the list of predictors of excessive GWG; variables with p < .1 were included in a path analysis. Results: Age, family income, T2 depression, T2 pregnancy-specific coping, T1 buttocks dissatisfaction, T2 GWG-specific self-efficacy, T1 dietary readiness, T1 dietary importance, and T1 vegetable intake predicted excessive GWG in the logistic regressions and were included in the path model. The baseline path model demonstrated poor fit. Once statistically and theoretically plausible paths were added, adequate model fit was achieved (χ² = 21.61(9), p < .05; RMSEA = .07; CFI = .93); this revised model explained 19.5% of the variance in excessive GWG. Women with high T1 buttocks dissatisfaction were more likely to exhibit low levels of dietary readiness. Women with low dietary readiness were more likely to have a lower vegetable intake, which predicted excessive GWG. Women with higher T2 depressive symptoms were more likely to report lower GWG self-efficacy and gain excessively. Conclusion: Future behavioural GWG trials should consider combining psychosocial and health behaviour change factors to optimise GWG.