Background: Physical activity is associated with reduced risks of many chronic diseases. Data collected on physical activity in large epidemiological studies is often based on paper questionnaires. The validity of these questionnaires is debated, and more effective methods are needed. Objective: This study evaluates repeated measures of physical activity level (PAL) and the feasibility of using a Java-based questionnaire downloaded onto cell phones for collection of such data. The data obtained were compared with reference estimates based on the doubly labeled water method and indirect calorimetry (PAL(ref)). Method: Using a Java-based cell phone application, 22 women reported their physical activity based on two short questions answered daily over a 14-day period (PAL(cell)). Results were compared with reference data obtained from the doubly labeled water method and indirect calorimetry (PAL(ref)). Results were also compared against physical activity levels assessed by two regular paper questionnaires completed by women at the end of the 14-day period (PAL(quest1) and PAL(quest2)). PAL(cell), PAL(quest1), and PAL(quest2) were compared with PAL(ref) using the Bland and Altman procedure. Results: The mean difference between PAL(cell), and PAL(ref) was small (0.014) with narrow limits of agreement (2SD = 0.30) Compared with PAL(ref) the mean difference was also small for PAL(quest1) and PAL(quest2) (0.004 and 0.07, respectively); however, the limits of agreement were wider (PAL(quest), 2SD = 0.50 and PAL(quest2), 2SD = 0.90). The test for trend was statistically significant for PAL(quest1) (slope of regression line = 0.79, P = .04) as well as for PAL(quest2) (slope of regression line = 1.58, P andlt; .001) when compared with PAL(ref). Conclusion: A Java-based physical activity questionnaire administered daily using cell phones produced PAL estimates that agreed well with PAL reference values. Furthermore, the limits of agreement between PAL obtained using cell phones, and reference values were narrower than for corresponding estimates obtained using paper questionnaires. Java-based questionnaires downloaded onto cell phones may be a feasible and cost-effective method of data collection for large-scale prospective studies of physical activity.

Background: Physical activity promotes health and longevity. Further elaboration of the role of physical activity for human health in epidemiological studies on large samples requires accurate methods that are easy to use, cheap, and possible to repeat. The use of telecommunication technologies such as cell phones is highly interesting in this respect. In an earlier report, we showed that physical activity level (PAL) assessed using a cell phone procedure agreed well with corresponding estimates obtained using the doubly labeled water method. However, our earlier study indicated high within-subject variation in relation to between-subject variations in PAL using cell phones, but we could not assess if this was a true variation of PAL or an artifact of the cell phone technique. less thanbrgreater than less thanbrgreater thanObjective: Our objective was to compare within-and between-subject variations in PAL by means of cell phones with corresponding estimates using an accelerometer. In addition, we compared the agreement of daily PAL values obtained using the cell phone questionnaire with corresponding data obtained using an accelerometer. less thanbrgreater than less thanbrgreater thanMethods: PAL was measured both with the cell phone questionnaire and with a triaxial accelerometer daily during a 2-week study period in 21 healthy Swedish women (20 to 45 years of age and BMI from 17.7 kg/m(2) to 33.6 kg/m(2)). The results were evaluated by fitting linear mixed effect models and descriptive statistics and graphs. less thanbrgreater than less thanbrgreater thanResults: With the accelerometer, 57% (95% confidence interval [CI] 40%-66%) of the variation was within subjects, while with the cell phone, within-subject variation was 76% (95% CI 59%-83%). The day-to-day variations in PAL observed using the cell phone questions agreed well with the corresponding accelerometer results. less thanbrgreater than less thanbrgreater thanConclusions: Both the cell phone questionnaire and the accelerometer showed high within-subject variations. Furthermore, day-to-day variations in PAL within subjects assessed using the cell phone agreed well with corresponding accelerometer values. Consequently, our cell phone questionnaire is a promising tool for assessing levels of physical activity. The tool may be useful for large-scale prospective studies.

It is increasingly acknowledged that the maternal diet influences fetal development and health of the child. Milk and milk products contribute essential nutrients and bioactive substances; they are of ample supply and have a long tradition in Nordic countries. To revise and update dietary guidelines for pregnant women valid in Nordic countries, the Pregnancy and Lactation expert group within the NNR5 project identified a need to systematically review recent scientific data on infant growth measures and maternal milk consumption. The objective of this study was to assess the influence of milk and dairy consumption during pregnancy on fetal growth through a systematic review of studies published between January 2000 and December 2011. A literature search was run in June 2011. Two authors independently selected studies for inclusion from the 495 abstracts according to predefined eligibility criteria. A complementary search in January 2012 revealed 64 additional abstracts published during the period June to December 2011, among them one study of interest previously identified. Of the 33 studies extracted, eight were relevant research papers. Five were prospective cohort studies (including a retrospective chart review), one was a case-control study, and two were retrospective cohort studies. For fetal length or infant birth length, three studies reported no association and two reported positive associations with milk or dairy consumption. For birthweight related outcomes, two studies reported no associations, and four studies reported positive associations with milk and/or dairy consumption. There was large heterogeneity in exposure range and effect size between studies. A beneficial fetal growth-increase was most pronounced for increasing maternal milk intake in the lower end of the consumption range. Evidence from prospective cohort studies is limited but suggestive that moderate milk consumption relative to none or very low intake, is positively associated with fetal growth and infant birthweight in healthy, Western populations.

Background

A Mediterranean diet has a recognized beneficial effect on health and longevity, with a protective influence on several cancers. However, its association with breast cancer risk remains unclear.

Objective

We aimed to investigate whether adherence to a Mediterranean dietary pattern influences breast cancer risk.

Design

The Swedish Women’s Lifestyle and Health cohort study includes 49,258 women aged 30 to 49 years at recruitment in 1991–1992. Consumption of foods and beverages was measured at enrollment using a food frequency questionnaire. A Mediterranean diet score was constructed based on the consumption of alcohol, vegetables, fruits, legumes, cereals, fish, the ratio of unsaturated to saturated fat, and dairy and meat products. Relative risks (RR) for breast cancer and specific tumor characteristics (invasiveness, histological type, estrogen/progesterone receptor status, malignancy grade and stage) associated with this score were estimated using Cox regression controlling for potential confounders.

Results

1,278 incident breast cancers were diagnosed. Adherence to a Mediterranean dietary pattern was not statistically significantly associated with reduced risk of breast cancer overall, or with specific breast tumor characteristics. A RR (95% confidence interval) for breast cancer associated with a two-point increment in the Mediterranean diet score was 1.08 (1.00–1.15) in all women, and 1.10 (1.01–1.21) and 1.02 (0.91–1.15) in premenopausal and postmenopausal women, respectively. When alcohol was excluded from the Mediterranean diet score, results became not statistically significant.

Conclusions

Adherence to a Mediterranean dietary pattern did not decrease breast cancer risk in this cohort of relatively young women.

In recent decades the number of children with overweight has increased worldwide. To understand the mechanisms behind this development, knowledge regarding metabolism and physiology in relation to the nutritional situation in early life is of importance. In particular, information about body composition development during early childhood is relevant. This thesis presents three studies in this area. In the pregnancy study serum samples, collected from 23 women before, during and after pregnancy, were analysed for serum levels of leptin, adiponectin and resistin and used to assess insulin resistance (HOMA-IR) in relation to the total body fat (TBF) content of the women. TBF (%) and leptin were significantly correlated with HOMA-IR before and during pregnancy. When HOMA-IR was regressed on TBF (%) the slope of the regression line was 0.111 in gestational week 32 and significantly (p<0.05) higher than the value before pregnancy, 0.046, indicating that healthy pregnancy enhances the relationship between body fatness and insulin resistance. In the HF-study hydration of fat-free mass (hydration factor, HF) was assessed in 12 newborns using the doubly labelled water (DLW) method and air displacement plethysmography (PeaPod). HF was 80.9% with a low biological variability (0.81% of average HF). In the longitudinal study the body density of 108 healthy fullterm infants (53 girls, 55 boys) was measured at one and 12 weeks of age using PeaPod. Body composition was calculated using two models (Fomon’s and Butte’s). BMI values for the mothers of the infants were assessed before pregnancy. Body composition and total energy expenditure using the DLW-method were assessed in 20 of these children at the age of 1.5 years, when their sleeping metabolic rate was measured using indirect calorimetry and their resting energy metabolism was calculated using prediction equations. Butte´s model gave significantly (p<0.05) lower values for TBF than Fomon´s model, and invalid results for five newborns. Using Fomon´s model, at one week of age girls contained 13.4 ± 3.7 % and boys contained 12.5 ± 4.0 % TBF. The corresponding figures at 12 weeks were 26.3 ± 4.2 % and 26.4 ± 5.1 %. The mothers’ BMI values before pregnancy were correlated with the body weight but not with the TBF (g,%) or fat-free mass (g) of their infants at one week of age. At 1.5 years of age girls (n=9) contained 28.0±2.8 % and boys (n=11) 28.3±3.7 % TBF. Between one and 12 weeks of age all infants increased their TBF content, while 13 children increased and seven children decreased their TBF content between the ages of 12 weeks and 1.5 years. The results demonstrated that predicting rather than measuring resting energy metabolism involves a risk for spurious correlations between TBF and physical activity level. The level of physical activity (x), was negatively correlated with [TBF (%) at 1.5 years minus TBF (%) at 12 weeks] (y), r=-0.52, p=0.02. In conclusion, the results suggest that the body fat content of a woman has a stimulating effect on the growth, rather than on the fat retention, of her foetus. They also show that the Fomon model is the best available model when calculating the body composition of infants from body density. Finally, the results indicate that physical activity at the age of 1.5 years is important regarding the rate at which the high level of body fat, typical of infancy, decreases in early childhood.

Background: The prevalence of childhood overweight and obesity has increased recently, but the mechanisms involved are incompletely known. Previous research has shown a correlation between the percentage of total body fat (TBF) and physical activity level (PAL). However, the PAL values used may involve a risk of spurious correlations because they are often based on predicted rather than measured estimates of resting energy metabolism. less thanbrgreater than less thanbrgreater thanObjectives: We studied the development of body composition during early childhood and the relation between the percentage of TBF and PAL on the basis of the measured resting energy metabolism. less thanbrgreater than less thanbrgreater thanDesign: Body composition was previously measured in 108 children when they were 1 and 12 wk old. When 44 of these children (21 girls and 23 boys) were 1.5 y old, their total energy expenditure and TBF were assessed by using the doubly labeled water method. Resting energy metabolism, which was assessed by using indirect calorimetry, was used to calculate PAL. less thanbrgreater than less thanbrgreater thanResults: Significant correlations were shown for TBF (r = 0.32, P = 0.035) and fat-free mass (r = 0.34, P = 0.025) between values (kg) assessed at 12 wk and 1.5 y of age. For TBF (kg) a significant interaction (P = 0.035) indicated a possible sex difference. PAL at 1.5 y was negatively correlated with the percentage of TBF (r = -0.40, P = 0.0076) and the increase in the percentage of TBF between 12 wk and 1.5 y (r = 0.38, P = 0.0105). less thanbrgreater than less thanbrgreater thanConclusions: The results indicate that body fatness and physical activity interact during early childhood and thereby influence obesity risk. Our results are based on a small sample, but nevertheless, they motivate additional studies in boys compared with girls regarding the development of body composition during early life.

Aim: To use Pea Pod, a device based on air displacement plethysmography, to study body composition of healthy, full-term infants born to well-nourished women with a western life-style. Methods: Body composition was assessed in 53 girls and 55 boys at 1 week (before 10 days of age) and at 12 weeks (between 77 and 91 days of age). Results: At 1 week girls contained 13.4 +/- 3.7% body fat and boys 12.5 +/- 4.0%. At 12 weeks, these figures were 26.3 +/- 4.2% (girls) and 26.4 +/- 5.1% (boys). Body fat (%) did not differ significantly between the genders. Body fat (%) at the two measurements was not correlated. At 1 week, the weight (r = 0.20, p = 0.044) and BMI (r = 0.26, p = 0.007) of the infants, but not their body fat (g, %) or fat free mass (g), correlated with BMI before pregnancy in their mothers. Conclusions: Pea Pod has potential for use in studies investigating the effect of external (i.e. nutritional status) and internal (i.e. age, gender, gestational age at birth) factors on infant body composition. This may be of value when studying relationships between the nutritional situation during early life and adult health.

Equipment (Pea Pod) for assessing infant body density accurately and conveniently has recently become available. This density can be converted to body composition using the “Fomon” or the “Butte” model. These models differ regarding the water content in fat-free mass (hydration factor, HF). We assessed HF and its biological variability in newborns and compared results calculated using the two models at one and 12 weeks. Body volume and body weight were measured in 12 infants less than 10 days old using Pea Pod. Their total body water was assessed using isotope dilution. Their HF was found to be 80.9% with low biological variability (0.81% of average HF). Further, Pea Pod was used to assess body density of 108 infants at one and 12 weeks of age. Values for body fat (%) calculated using the “Butte” model were significantly lower than when using the “Fomon” model at one week (p<0.05) and 12 weeks (p<0.01). The difference between the two models was particularly large at one week, probably due to their different HF-values. Our HF-value is in agreement with that in the “Fomon” model and our results support the conclusion that this model is preferable when calculating body composition in infants.

Healthy human pregnancy is associated with changes in food intake, body fatness, energy expenditure and insulin resistance. However, available knowledge is limited regarding the physiological basis of these changes. Published evidence suggests that so-called adipokines (i.e. leptin, adiponectin and resistin) have significant roles when such changes are established. We explored, throughout a complete pregnancy, relationships between total body fat (TBF), energy expenditure, insulin resistance (homeostasic model of insulin resistance, HOMA-IR) and serum concentrations of leptin, adiponectin and resistin. Such concentrations were assessed before pregnancy in gestational weeks 8, 14, 20, 32 and 35, and 2 weeks postpartum in twenty-three healthy women. TBF, BMR (n 23) and HOMA-IR (n 17) were assessed before pregnancy in gestational weeks 14 and 32 and 2 weeks postpartum. TBF (%) was correlated with HOMA-IR (r 0.68-0.79, P < 0.01) and with serum leptin (r 0.85-0.88, P < 0.001) before and during pregnancy. Serum leptin was correlated with HOMA-IR (r 0.53-0.70, P < 0.05) before and during pregnancy. Serum adiponectin was inversely correlated with HOMA-IR in gestational week 32 (r - 0.52, P < 0.05). When HOMA-IR was regressed on TBF (%), the slope of the regression line was 0.046 before pregnancy, which was significantly (P < 0.05) different from the corresponding value, 0.111, in gestational week 32. The results indicate that pregnancy has an enhancing effect on the relationship between body fatness and insulin resistance. This effect, possibly mediated by leptin, may represent a mechanism by which offspring size is regulated in response to the nutritional situation of the mother.

During recent decades the prevalence of overweight and obesity in childhood has increased and studies of the mechanisms involved are motivated. Previous research has shown a correlation between total body fat (TBF) (%) and physical activity level (PAL) but the assessment of PAL has often involved a risk for spurious correlations. Thus we compared PAL calculated using basal metabolic rate (BMR) predicted from equations, based on body weight (PALBMR) and associated with a risk for spurious correlations, with PAL calculated using sleeping metabolic rate (SMR) assessed using indirect calorimetry (PALSMR) in 20 healthy children aged 1.5 years. Total energy expenditure and body fatness were assessed using the doubly labelled water method. Body fatness of these children was also assessed at one week and three months of age. PALBMR was significantly (r=-0.48, p=0.03) correlated with TBF (%) while PALSMR was not. Furthermore, the increase in body fatness between three months and 1.5 years was significantly (r=-0.52, p=0.02) correlated with PALSMR at the age of 1.5 years. Our results indicate complex relationships between body fatness and physical activity in early life. When conducting studies in this area, resting energy metabolism should be measured rather than predicted using equations based on body weight.

The prevalence of overweight and obesity in women has increased during the last decades. This is a serious concern since a high BMI before conception is an independent risk factor for many adverse outcomes of pregnancy. Therefore, dietary counseling, intended to stimulate weight loss in overweight and obese women prior to conception has recently been recommended. However, dieting with the purpose to lose weight may involve health risks for mother and offspring. We conducted a systematic literature review to identify papers investigating the effects of weight loss due to dietary interventions before conception. The objective of this study is to assess the effect of weight loss prior to conception in overweight or obese women on a number of health-related outcomes in mother and offspring using studies published between January 2000 and December 2011. Our first literature search produced 486 citations and, based on predefined eligibility criteria, 58 were selected and ordered in full text. Two group members read each paper. Fifteen studies were selected for quality assessment and two of them were considered appropriate for inclusion in evidence tables. A complementary search identified 168 citations with four papers being ordered in full text. The two selected studies provided data for overweight and obese women. One showed a positive effect of weight loss before pregnancy on the risk of gestational diabetes and one demonstrated a reduced risk for large-for-gestational-age infants in women with a BMI above 25 who lost weight before pregnancy. No study investigated the effect of weight loss due to a dietary intervention before conception. There is a lack of studies on overweight and obese women investigating the effect of dietary-induced weight loss prior to conception on health-related variables in mother and offspring. Such studies are probably lacking since they are difficult to conduct. Therefore, alternative strategies to control the body weight of girls and women of reproductive age are needed.

This review summarizes information regarding how human energy metabolism is affected by pregnancy, and current estimates of energy requirements during pregnancy are presented. Such estimates can be calculated using either increases in basal metabolic rate (BMR) or increases in total energy expenditure (TEE). The two modes of calculation give similar results for a complete pregnancy but different distributions of energy requirements in the three trimesters. Recent information is presented regarding the effect of pregnancy on BMR, TEE, diet-induced thermogenesis, and physical activity. The validity of energy intake (EI) data recendy assessed in well-nourished pregnant women was evaluated using information regarding energy metabolism during pregnancy. The results show that underreporting of EI is common during pregnancy and indicate that additional longitudinal studies, taking the total energy budget during pregnancy into account, are needed to satisfactorily define energy requirements during the three trimesters of gestation. Copyright © 2007 by Annual Reviews. All rights reserved.

Background: Dietary intake of phytoestrogens has been inversely associated to hormone-dependent cancers, such as prostate and breast cancers. Few studies have investigated the association between ovarian cancer and intake of phytoestrogens. We evaluated the associations between intake of phytoestrogens (isoflavonoids/lignans/coumestrol) and fiber (vegetable/cereal) and risk of ovarian cancer. Methods: In 1991-1992 a prospective population-based cohort study among Swedish women was conducted, including 47,140 women with complete dietary questionnaire data. During follow-up until December 2007, 163 women developed invasive (n = 117) and borderline (n = 46) ovarian cancers. The median follow-up time was 16 years and total person year was 747,178. Cox proportional hazards models were conducted to estimate multivariate risk ratios, 95% CI for associations with risk of ovarian cancer. Results: We found no association between intake of phytoestrogens or fiber and overall ovarian cancer risk. In addition, we found no statistically significant association between intake of specific food items rich in phytoestrogens (berries, nuts, beans/soy, and crisp or whole-grain bread) and ovarian cancer risk overall. Fiber and coumestrol was inversely associated with borderline ovarian cancer, but not with invasive ovarian cancer. Conclusions: We found no association between intake of phytoestrogens or fiber and overall ovarian cancer risk. Impact: Phytoestrogens do not play a major etiologic role in ovarian cancer, at least among women in this Swedish cohort with low bean/soy intake. However, our results of a difference in the effect of fiber or coumestrol between invasive and borderline ovarian cancer need to be evaluated in larger studies.

Assessment of body fat (BF) in pregnant women is important when investigating the relationship between maternal nutrition and offspring health. Convenient and accurate body composition methods applicable during pregnancy are therefore needed. Air displacement plethysmography, as applied in Bod Pod, represents such a method since it can assess body volume (BV) which, in combination with body weight, can be used to calculate body density and body composition. However, BV must be corrected for the thoracic gas volume (TGV) of the subject. In non-pregnant women, TGV may be predicted using equations, based on height and age. It is unknown, however, whether these equations are valid during pregnancy. Thus, we measured the TGV of women in gestational week 32 (n 27) by means of plethysmography and predicted their TGV using equations established for non-pregnant women. Body weight and BV of the women was measured using Bod Pod. Predicted TGV was significantly (P = 0.033) higher than measured TGV by 6% on average. Calculations in hypothetical women showed that this overestimation tended to be more pronounced in women with small TGV than in women with large TGV. The overestimation of TGV resulted in a small but significant (P = 0.043) overestimation of BF, equivalent to only 0.5% BF, on average. A Bland-Altman analysis showed that the limits of agreement were narrow (from -1.9 to 2.9% BF). Thus, although predicted TGV was biased and too high, the effect on BF was marginal and probably unimportant in many situations.

Estrogen receptornegative (ER) breast cancer has few known or modifiable risk factors. Because ER tumors account for only 15% to 20% of breast cancers, large pooled analyses are necessary to evaluate precisely the suspected inverse association between fruit and vegetable intake and risk of ER breast cancer. less thanbrgreater than less thanbrgreater thanAmong 993 466 women followed for 11 to 20 years in 20 cohort studies, we documented 19 869 estrogen receptor positive (ER) and 4821 ER breast cancers. We calculated study-specific multivariable relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression analyses and then combined them using a random-effects model. All statistical tests were two-sided. less thanbrgreater than less thanbrgreater thanTotal fruit and vegetable intake was statistically significantly inversely associated with risk of ER breast cancer but not with risk of breast cancer overall or of ER tumors. The inverse association for ER tumors was observed primarily for vegetable consumption. The pooled relative risks comparing the highest vs lowest quintile of total vegetable consumption were 0.82 (95% CI 0.74 to 0.90) for ER breast cancer and 1.04 (95% CI 0.97 to 1.11) for ER breast cancer (Pcommon-effects by ER status andlt; .001). Total fruit consumption was non-statistically significantly associated with risk of ER breast cancer (pooled multivariable RR comparing the highest vs lowest quintile 0.94, 95% CI 0.85 to 1.04). less thanbrgreater than less thanbrgreater thanWe observed no association between total fruit and vegetable intake and risk of overall breast cancer. However, vegetable consumption was inversely associated with risk of ER breast cancer in our large pooled analyses.

The relationship between solar exposure or dietary vitamin D intake and breast cancer risk has not been fully elucidated. These associations were studied within the Womens Lifestyle and Health Cohort Study, a cohort of 49,259 Swedish women ages 30 to 50 years at baseline (1991-1992). Women were asked about solar exposure and completed a food frequency questionnaire and were followed-up through linkages to national registries until December 2004. In the current analyses, 41,889 women were included, 840 of whom were diagnosed with breast cancer during follow-up. Breast cancer risk was not related to solar exposure variables, including sun sensitivity, annual number of sunburns, time spent on sunbathing vacations, or solarium use at any age period of exposure. There was also no association with dietary vitamin D intake or supplementary multivitamin use. These relationships were not modified after stratifying by estrogen or progesterone receptor status.

n/a

Objective To study the long term consequences of low carbohydrate diets, generally characterised by concomitant increases in protein intake, on cardiovascular health. Design Prospective cohort study. Setting Uppsala, Sweden. Participants From a random population sample, 43 396 Swedish women, aged 30-49 years at baseline, completed an extensive dietary questionnaire and were followed-up for an average of 15.7 years. Main outcome measures Association of incident cardiovascular diseases (ascertained by linkage with nationwide registries), overall and by diagnostic category, with decreasing carbohydrate intake (in tenths), increasing protein intake (in tenths), and an additive combination of these variables (low carbohydrate-high protein score, from 2 to 20), adjusted for intake of energy, intake of saturated and unsaturated fat, and several non-dietary variables. Results A one tenth decrease in carbohydrate intake or increase in protein intake or a 2 unit increase in the low carbohydrate-high protein score were all statistically significantly associated with increasing incidence of cardiovascular disease overall (n=1270)-incidence rate ratio estimates 1.04 (95% confidence interval 1.00 to 1.08), 1.04 (1.02 to 1.06), and 1.05 (1.02 to 1.08). No heterogeneity existed in the association of any of these scores with the five studied cardiovascular outcomes: ischaemic heart disease (n=703), ischaemic stroke (n=294), haemorrhagic stroke (n=70), subarachnoid haemorrhage (n=121), and peripheral arterial disease (n=82). Conclusions Low carbohydrate-high protein diets, used on a regular basis and without consideration of the nature of carbohydrates or the source of proteins, are associated with increased risk of cardiovascular disease.

Background/Objectives: Energy costs of pregnancy approximate 320 MJ in well-nourished women, but whether or not these costs may be partly covered by modifications in activity behavior is incompletely known. In healthy Swedish women: (1) to evaluate the potential of the Intelligent Device for Energy Expenditure and Physical Activity (IDEEA) to assess energy expenditure during free-living conditions, (2) to assess activity pattern, walking pace and energy metabolism in pregnant women and non-pregnant controls, and (3) to assess the effect on energy expenditure caused by changes in physical activity induced by pregnancy. less thanbrgreater than less thanbrgreater thanSubjects/Methods: Activity pattern was assessed using the IDEEA in 18 women in gestational week 32 and in 21 non-pregnant women. Activity energy expenditure (AEE) was assessed using IDEEA, as well as using the doubly labelled water method and indirect calorimetry. less thanbrgreater than less thanbrgreater thanResults: AEE using the IDEEA was correlated with reference estimates in both groups (r = 0.4-0.5; Pandlt;0.05). Reference AEE was 0.9 MJ/24 h lower in pregnant than in non-pregnant women. Pregnant women spent 92 min/24 h more on sitting, lying, reclining and sleeping (P = 0.020), 73 min/24 h less on standing (P = 0.037) and 21 min/24 h less on walking and using stairs (P = 0.049), and walked at a slower pace (1.1 +/- 0.1 m/s versus 1.2 +/- 0.1 m/s; P = 0.014) than did non-pregnant controls. The selection of less demanding activities and slower walking pace decreased energy costs by 720 kJ/24 h and 80 kJ/24 h, respectively. less thanbrgreater than less thanbrgreater thanConclusion: Healthy moderately active Swedish women compensated for the increased energy costs of pregnancy by 0.9 MJ/24 h. The compensation was mainly achieved by selecting less demanding activities.

[No abstract available]

Purpose of review

Breast cancer is the most common female cancer in Western Europe and North America, and becoming an increasing problem in developing countries such as India and China. We review recent studies (published 1 January 2007-31 August 2008) on the impact of diet on breast cancer risk.

Recent findings

Recent studies have focused on the controversial association for dietary fat and breast cancer as well as the role of newer aspects such as glycemic index, dietary patterns and diet-gene interactions. Evidence that some of the associations may be modified by oestrogen and progesterone receptor status has been presented. Still, only alcohol intake, being overweight and weight gain have shown consistent and strong positive associations with breast cancer risk. The reasons for the null or weak associations often observed regarding diet and breast cancer might be several. For example, there may be no causal association, or existing associations may be masked by measurement error, timing of dietary exposure and differences according to tumour characteristics or diet-gene interactions.

Summary

Numerous epidemiological studies on diet and breast cancer have been published during our review period. Still, only alcohol intake, being overweight and weight gain have shown consistent and strong positive associations with breast cancer risk.

Background: The maternal insulin-like growth factor (IGF) system is considered to be involved in fetal growth regulation. However, available data linking this system to fetal growth are contradictory and incomplete.

Aims: To measure components of the IGF system before, during and after pregnancy in healthy women and to relate these results, and their changes during pregnancy, to fetal weight (gestational week 31) and birth weight.

Methods: Serum concentrations of IGF-I, IGF-II, IGF-binding protein (IGFBP)-1, IGFBP-3 and IGFBP-3 protease activity were assessed in 23 women before conception, at weeks 8, 14, 20, 32 and 35 of pregnancy and 2 weeks postpartum. The data were analyzed using simple and multiple linear regression.

Results: One third of the variability in fetal weight was explained by IGF-I in combination with IGFBP-3 protease activity, both assessed at gestational week 32 (p = 0.013). Birth weight was negatively correlated (r = –0.43 to –0.59) with IGFBP-1 at gestational week 20 (p = 0.041), 32 (p = 0.012) and 35 (p = 0.003).

Conclusion: We propose there is a finely tuned balance among the components of the IGF system, providing a means for fetal growth regulation.

Maternal nutritional status, e.g. body weight and composition, is associated with fetal growth. It has been suggested that the insulin-like growth factor (IGF) system may be a mediator of this relationship. In twenty-three healthy Swedish women, we studied (1) the relationships before and during pregnancy between maternal serum concentrations of IGF-I and IGF binding protein-1 (IGFBP-1) and maternal body weight and composition; (2) interactions between serum concentrations of IGF-I (before and in early pregnancy) and maternal nutritional status in relation to infant birth weight. We found that serum IGF-I during pregnancy was positively correlated with maternal body weight (r 0·47–0·56) and fat-free body weight (r 0·61–0·65), whereas serum IGFBP-1 was negatively correlated with maternal body weight (r − 0·44 to − 0·69) and body fat (r − 0·64 to − 0·76) before and during pregnancy. Women with a lower body fat content (%) before pregnancy had greater increases in serum IGFBP-1 during pregnancy than women with a higher prepregnant body fat content (%). In addition, significant fractions of the variation in corrected infant birth weight were explained by variables related to the maternal nutritional status when these were combined with serum concentrations of IGF-I in gestational week 14 (adjusted r² 0·25–0·44, P = 0·001–0·021), but not when they were combined with such concentrations before pregnancy (adjusted r² 0·11–0·12, P = 0·105–0·121). These results suggest mechanisms by which the IGF system may be a mediator between maternal nutritional status and fetal growth.

Assessing body composition during infancy requires data for the so-called reference infant. Currently available data for this purpose need to be updated and extended using methods based on principles different from those used previously to define the reference infant. Thus, magnetic resonance imaging was applied to full-term healthy boys (n = 25) and girls (n = 21), 4-131 d old, to estimate adipose tissue volume (ATV) and the amounts of s.c. and non-s.c. adipose tissue (AT). Total body water was estimated using isotope dilution. Total body fat (TBF), fat free weight (FFW) and the degree of hydration in FFW were calculated. Increases in weight, TBF, and FFW with age agreed with current reference data, although when compared with the reference, a slightly more rapid increase in % TBF was observed for boys. The degree of hydration in FFW was 78.9 ± 4.5% (n = 45). Both sexes showed significant increases with age in s.c. ATV (14.7 and 13.0 mL/d for boys and girls, respectively) and in non-s.c. ATV (1.58 and 1.26 mL/d, respectively). Subcutaneous ATV was 90.5 ± 1.8% (boys) and 91.1 ± 1,9% (girls) of total ATV. In conclusion, a pronounced increase with age in the amount of AT was demonstrated involving a considerable gain in s.c. fat during early life. Except for % TBF in boys, changes in body composition with age agreed with current reference data.

An investigation in a randomized population-based Swedish study with 564 participants aged 18-80 years showed that mean physical activity levels obtained using short message service (SMS) by means of cell phones (n = 171) were equal to corresponding levels obtained when sending identical questions by web (n = 182) or paper (n = 211). The response rates were similar for the SMS, web and paper groups.

ackground: Few studies have compared the validity of objective measures of physical activity energy expenditure (PAEE) in pregnant and non-pregnant women. PAEE is commonly estimated with accelerometers attached to the hip or waist, but little is known about the validity and participant acceptability of wrist attachment. The objectives of the current study were to assess the validity of a simple summary measure derived from a wrist-worn accelerometer (GENEA, Unilever Discover, UK) to estimate PAEE in pregnant and non-pregnant women, and to evaluate participant acceptability. less thanbrgreater than less thanbrgreater thanMethods: Non-pregnant (N = 73) and pregnant (N = 35) Swedish women (aged 20-35 yrs) wore the accelerometer on their wrist for 10 days during which total energy expenditure (TEE) was assessed using doubly-labelled water. PAEE was calculated as 0.96TEE-REE. British participants (N = 99; aged 22-65 yrs) wore accelerometers on their non-dominant wrist and hip for seven days and were asked to score the acceptability of monitor placement (scored 1 [least] through 10 [most] acceptable). less thanbrgreater than less thanbrgreater thanResults: There was no significant correlation between body weight and PAEE. In non-pregnant women, acceleration explained 24% of the variation in PAEE, which decreased to 19% in leave-one-out cross-validation. In pregnant women, acceleration explained 11% of the variation in PAEE, which was not significant in leave-one-out cross-validation. Median (IQR) acceptability of wrist and hip placement was 9(8-10) and 9(7-10), respectively; there was a within-individual difference of 0.47 (p andlt; .001). less thanbrgreater than less thanbrgreater thanConclusions: A simple summary measure derived from a wrist-worn tri-axial accelerometer adds significantly to the prediction of energy expenditure in non-pregnant women and is scored acceptable by participants.

Background: Except for skin melanoma and nonmelanoma skin cancer, little evidence from prospective studies is available on the association between UV exposure and cancer risk. Methods: We followed prospectively 49,261 women aged 30 to 49 years at enrollment in 1991 to 1992 for 15 years. Cancer incidence was analyzed by fitting Cox models, and estimating hazard ratios (HR) and 95% confidence intervals (CI). Results: 2,303 incident cases of cancer were diagnosed (breast: 1,053, ovary: 126, lung: 116, colon-rectum: 133, and brain: 116). No associations were found between any cumulative measure of UV exposure at ages 10 to 39 years and overall cancer risk. However, spending greater than= 1 week/year between ages 10 and 29 years on sunbathing vacations led to an inverse association with overall cancer risk (HR: 0.70, 95% CI: 0.53-0.93) and breast cancer risk (HR: 0.56, 95% CI: 0.36-0.89) when compared with women who never went on such vacations. Solarium use was inversely associated with breast cancer risk, whereas greater than= 2 sunburns/year was inversely associated with lung cancer risk. No other associations were found between sun exposure or solarium use at ages 10 to 39 years and cancer risk. Conclusion: We found no evidence of an association between any cumulative measure of UV exposure at ages 10 to 39 years and overall cancer risk. UV exposure earlier in life was related to reduced overall and breast cancer risk. Impact: Further research is needed to define the amount of solar or artificial UV exposure that may, or may not, be beneficial for cancer prevention.