Dietary Carbohydrate Intake Does Not Impact Insulin Resistance or Androgens in Healthy, Eumenorrheic Women

Healthy eating index and risk of diminished ovarian reserve: a case-control study

Diminished ovarian reserve (DOR) is associated with reduced fertility and poor reproductive outcomes. The association between dietary patterns and DOR was not well studied. The purpose of this study was to evaluate the relationship between adhering to the healthy eating index (HEI-2015) and the risk of DOR. In this case-control study, 370 Iranian women (120 with DOR and 250 age- and BMI-matched controls) were examined. A reliable semi-quantitative food frequency questionnaire was used to collect diet-related data. We analyzed the HEI-2015 and their dietary intake data to determine major dietary patterns. The multivariable logistic regression was used in order to analyze the association between HEI-2015 and risk of DOR. We found no significant association between HEI-2015 score and risk of DOR in the unadjusted model (OR 0.78; 95%CI 0.59, 1.03). After controlling for physical activity and energy intake, we observed that women in the highest quartile of the HEI-2015 score had 31% decreased odds of DOR (OR 0.69; 95%CI 0.46, 0.93). This association remained significant even after adjusting for all potential confounders. Overall, increased adherence to HEI may lead to a significant reduction in the odds ratio of DOR. Clinical trials and prospective studies are needed to confirm this association.

Seasonal AMH variability implies a positive effect of UV exposure on the deterioration of ovarian follicles

Anti-Müllerian hormone (AMH) is produced exclusively by granulosa cells of ovarian follicles and is an indicator of ovarian reserve which declines with age. Seasonality in AMH levels have been reported to be correlated with variations in Vitamin D levels, which is dependent on sunlight exposure. However, the effects of age and its association with solar radiation intensity with respect to AMH was never studied before. In this study, we investigated the relationship between AMH levels with season and with solar radiation intensity in a cohort of 2235 women aged 19-40 years undergoing hormonal work-up over a four-year period. Our findings revealed that among women aged 20-29 years, there was no significant association between AMH levels and either season or solar radiation intensity. However, for women aged 30-40 years, a seasonal pattern was observed, with higher AMH levels during spring and autumn months characterized by moderate solar radiation intensity. Women in their declining ovarian reserve age were found to be more sensitive to the effects of moderate solar radiation. Moderate solar radiation exposure positively impacted AMH levels, whereas low and high intensity exposure had a negative effect. Our findings indicate that age and solar radiation intensity must be considered when assessing AMH levels and provide valuable insights into the intricate relationship between AMH, seasonality, and UVB exposure in the context of reproductive health.

Mediterranean diet and female reproductive health over lifespan: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis of the effects of Mediterranean diet on female reproductive health outcomes over the life-course.

DATA SOURCES

We searched PubMed, Embase, MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov to identify eligible studies published till February 2022. Eligible references from identified studies and review articles were also considered.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials, prospective cohort studies, or nested case-control studies examining Mediterranean diet and major female reproductive outcomes over the lifespan, including clinical outcomes from childhood to adulthood (menarche, polycystic ovary syndrome, endometriosis, and outcomes related to fertility, pregnancy, and menopause), were included for review.

METHODS

Two independent reviewers screened and performed data extraction and risk-of-bias assessment. We performed random-effects meta-analysis to obtain summary relative risks and 95% confidence intervals for major female reproductive outcomes. Subgroup analyses were performed for several pregnancy outcomes according to timing of the interventions for randomized controlled trials and timing of the dietary assessment for observational studies.

RESULTS

Thirty-two studies (9 randomized controlled trials, 22 prospective cohort studies, and 1 nested case-control study) involving 103,204 predominantly White women (>95%) were included. The pooled relative risk (95% confidence interval) comparing randomization to Mediterranean diet vs a control diet based on 7 randomized controlled trials was 0.74 (0.55-0.99) for gestational diabetes mellitus, 0.45 (0.26-0.76) for preterm birth, 0.71 (0.51-1.00) for gestational hypertension, and 0.82 (0.54-1.22) for preeclampsia; the effect sizes for preterm birth were greater in randomized controlled trials that initiated the interventions in first trimester vs after first trimester (P heterogeneity=.02). We observed inverse associations for all the above-mentioned pregnancy outcomes based on 9 cohort studies. There was suggestive evidence of favorable associations between Mediterranean diet adherence with fertility and gestational weight management. Limited studies suggested associations between higher Mediterranean diet adherence and later time to menarche and fewer vasomotor menopausal symptoms, null associations for polycystic ovary syndrome-like phenotype and pregnancy loss, and positive associations for luteal phase deficiency.

CONCLUSION

Adherence to Mediterranean diet may lower risks of adverse pregnancy outcomes among predominantly White populations. For fertility-related outcomes, available evidence supporting potential beneficial effects is suggestive yet limited. For other reproductive outcomes across the lifespan, data remains sparse.

Development of a nutrition screening tool to identify need for dietetic intervention in female infertility

BACKGROUND

One in seven couples are impacted by infertility in the UK, and female infertility is often associated with several health conditions impacted by nutrition. Despite many studies aimed at identifying the critical role of nutrition in infertility, there is currently no screening tool that identifies nutritional risk factors for infertility.

AIM

To propose a self-administered screening tool to identify women who would benefit from nutritional intervention to promote fertility.

METHODS

A narrative review was carried out to identify and summarise modifiable nutritional risk factors that can influence female fertility, including comorbidities that can influence nutrition intake, absorption, and metabolism.

KEY FINDINGS

A nutrition screening tool outlining modifiable nutrition risk factors potentially improving female fertility has been proposed, comprising of BMI, medical history and quality of diet and lifestyle which would aid in designing evidence based dietetic services for female infertility.

Dietary Fiber Supplementation in Replacement Gilts Improves the Reproductive Performance From the Second to Fifth Parities

This study examined the effects of soluble fiber (SF) supplementation (0.8%), containing 17.4% rhamnose, 4.1% fucose, 11.1% arabinose, 30.6% xylose, and 16.4% galactose during the prepubescent phase on the subsequent performance from the second to fifth parities. After the first parity, 56 and 55 post-weaning sows in the control (CON) and SF groups had their reproductive performance monitored in succeeding parities. Circulating concentrations of anti-mullerian hormone (AMH) were greater in the SF group than in the CON group at 205 d of age and the first post-weaning day (p < 0.05). The SF treatment at the prepubescent phase resulted in an enhanced reproductive performance from parities three to five. In Parity three, the SF sows had 1.32 total born (p = 0.044), 1.43 born alive (p = 0.023) and 1.40 born effective, which was significantly more than in the CON group (p = 0.022). In Parity four, the SF sows had 1.1 total born (p = 0.058), 1.28 born alive (p = 0.019), and 1.06 born effective, significantly more than in the CON group (p = 0.049). In Parity five, the SF gilts had 1.43 total born (p = 0.075), 1.53 born alive (p = 0.067) and 1.65 born effective, significantly more than in the CON group (p = 0.020). No effects were observed for the removal of sows and backfat thickness at the mating in each parity between groups (p > 0.05). Collectively, gilts that received an extra 0.8% SF during the prepubescent phase increased their subsequent litter size as breeding sows. These results showed that nutritional decisions at the replacement phase could influence lifetime fertility.

Effect of reproductive and lifestyle factors on anti-mullerian hormone levels in women of Indian origin

Background:

Infertility is a world-wide problem and one third females. Over the years, anti-mullerian hormone (AMH) has emerged as a major marker of ovarian reserve. There is also increasing interest in determining the factors which can impact AMH levels.

Aims:

To correlate the association of reproductive and lifestyle factors on AMH levels in women of Indian origin.

Settings and Design:

Multicentric cross sectional study.

Materials and Methods:

The study was conducted using data extracted from the patient records of seven private fertility practices located in North India. Women who were attending these clinics for fertility treatment were requested to fill the questionnaire related to reproductive and lifestyle factors.

Statistical Analysis used:

Our outcome variable was level of AMH measured in the past 3 months, and was assessed as normal or low. All analyses were conducted using STATA 17.

Results:

We found a direct association of low AMH with increasing age, short cycles, amenorrhea and women with family history of premature menopause. We found a direct correlation of high AMH and women with polycystic ovary syndrome and those whose partners had Oligoasthenoteratozoospermia (OATS) or azoospermia. There was no correlation with smoking, sleep, diet, body mass index, cell phone or laptop use in our study.

Conclusion:

Reproductive and lifestyle factors may affect ovarian reserve and but there was a dearth of human studies in this area. To the best of our knowledge this is the first human study on the effect of AMH on Laptop and Cell phone use. We urgently need more studies to confirm or refute our findings so that we can counsel our patients well.

The association between the levels of anti-Müllerian hormone (AMH) and dietary intake in Iranian women

PURPOSE

This paper aimed to assess the association between AMH with dietary intake of adult women referred to the infertility clinic of Al-Zahra Hospital in Rasht, Iran.

METHODS

This cross-sectional study was performed on 234 adult women referred to the infertility clinic of Al-Zahra Hospital, Rasht, Iran. The participants were categorized into two groups based on their AMH levels. Participants' data on lifestyle and anthropometry as well as blood samples were collected. Dietary intakes were assessed by a validated food frequency questionnaire (FFQ).

RESULTS

Serum AMH concentration was negatively associated with the intake of fast foods (P = 0.002) and saturated fats (P = 0.040). These associations remained significant after adjustments for age, rural or urban location, and education. Additional adjustments for body mass index (BMI) and physical activity did not change the results. The results remained significant after further adjustments for menstrual age, menstrual pattern, and oral contraceptive pills.

CONCLUSION

Fast foods and saturated fats were significantly associated with lower AMH concentrations and modifying the amount of these dietary components may be an important strategy for increasing the reservation of ovaries in women. Future longitudinal studies are warranted to confirm these findings and to identify the underlying mechanisms.

Associations between blood cadmium and endocrine features related to PCOS-phenotypes in healthy women of reproductive age: a prospective cohort study

BACKGROUND

Cadmium is an endocrine disrupting chemical that affects the hypothalamic-pituitary-gonadal axis. Though evidence suggests its potential role in altering androgen synthesis and metabolic pathways that are characteristic of polycystic ovary syndrome (PCOS), its relation in healthy women of reproductive age is largely unknown. As women with mild sub-clinical features of PCOS who do not meet the diagnostic criteria of PCOS may still experience reduced fecundability, investigating associations between cadmium and PCOS-phenotypes among healthy women may provide unique insight into the reproductive implications for many on the PCOS spectrum. Therefore, the objective of this study was to evaluate associations between cadmium and androgens, anti-Müllerian hormone (AMH), and metabolic markers in women of reproductive age.

METHODS

This was a prospective cohort study of 251 healthy premenopausal women without self-reported PCOS (mean age 27.3 years and BMI 24.1 kg/m²). Cadmium was measured in blood collected at baseline. Reproductive hormones and metabolic markers were measured in fasting serum 8 times per menstrual cycle for 2 cycles. Linear mixed models and Poisson regression with a robust error variance were used to examine associations between cadmium and reproductive hormones and metabolic markers and anovulation, respectively.

RESULTS

Median (interquartile range) blood cadmium concentrations at baseline were 0.30 (0.19-0.43) µg/L. Higher levels of testosterone (2.2 %, 95 % confidence interval [CI] 0.4, 4.1), sex hormone-binding globulin (2.9 %, 95 % CI 0.5, 5.5), and AMH (7.7 %, 95 % CI 1.1, 14.9) were observed per 0.1 µg/L increase in cadmium concentrations. An 18 % higher probability of a mild PCOS-phenotype (95 % CI 1.06, 1.31), defined by a menstrual cycle being in the highest quartile of cycle-averaged testosterone and AMH levels, was also found per 0.1 µg/L increase in cadmium levels. No associations were observed for insulin and glucose. These findings were consistent even after analyses were restricted to non-smokers or further adjusted for dietary factors to account for potential sources of exposure.

CONCLUSIONS

Overall, among healthy reproductive-aged women, cadmium was associated with endocrine features central to PCOS, but not with metabolic markers. These suggest its potential role in the hormonal milieu associated with PCOS even at low levels of exposure.

Effects of Dietary Glycemic Index and Glycemic Load on Cardiometabolic and Reproductive Profiles in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Women with polycystic ovary syndrome (PCOS) exhibit cardiometabolic (e.g., insulin resistance) and associated reproductive disruptions. Lifestyle modification (e.g., diet) is recommended as the first-line therapy to manage PCOS; however, a favorable dietary regimen remains unclear beyond energy restriction. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to summarize evidence on impacts of dietary glycemic index (GI) or glycemic load (GL) on cardiometabolic and reproductive profiles to update the International Evidence-based Guideline for the Assessment and Management of PCOS. Databases of MEDLINE, Cochrane, Web of Science, and Scopus were searched through 30 October 2019, and confirmed on 25 March 2020, to identify RCTs (≥8 wk) comparing the effects of diets with lower (LGI/LGL) and higher (HGI/HGL) GI/GL on glucoregulatory outcomes, lipid profile, anthropometrics, and androgen status in PCOS. The primary outcome was HOMA-IR. Data were pooled by random-effects models and expressed as weighted mean differences and 95% CIs. The risk of bias was assessed by the Cochrane tool. Ten RCTs (n = 403) were eligible. Eight evaluated LGI and 2 LGL diets. LGI diets decreased HOMA-IR (-0.78; -1.20, -0.37; I2 = 86.6%), fasting insulin (-2.39; -4.78, 0.00 μIU/mL; I2 = 76.8%), total cholesterol (-11.13; -18.23, -4.04 mg/dL; I2 = 0.0%), LDL cholesterol (-6.27; -12.01, -0.53 mg/dL; I2 = 0.0%), triglycerides (-14.85; -28.75, -0.95 mg/dL; I2 = 31.0%), waist circumference (-2.81; -4.40, -1.23 cm; I2 = 53.9%), and total testosterone (-0.21; -0.32, -0.09 nmol/L; I2 = 8.6%) compared with HGI diets (all: P ≤ 0.05) without affecting fasting glucose, HDL cholesterol, weight, or free androgen index (all: P ≥ 0.07). Some results were contradictory and only described narratively for 2 RCTs that evaluated LGL diets, since inclusion in meta-analyses was not possible. LGI diets improved glucoregulatory outcomes (HOMA-IR, insulin), lipid profiles, abdominal adiposity, and androgen status, conceivably supporting their inclusion for dietary management of PCOS. Further RCTs should confirm these observations and address whether LGI diets improve more patient-pressing complications, including ovulatory cyclicity, infertility, and cardiovascular disease risk in this high-risk population. This review was registered at www.crd.york.ac.uk/PROSPERO as CRD42020175300.

Dietary patterns and ovarian reserve among women attending a fertility clinic

OBJECTIVE

To investigate the associations between dietary patterns and antral follicle count (AFC), a marker of ovarian reserve.

DESIGN

Prospective cohort study.

SETTING

Fertility center at an academic hospital.

PATIENT(S)

A total of 363 women seeking preconception evaluation and infertility care at the Massachusetts General Hospital who participated in the Environment and Reproductive Health Study.

INTERVENTION(S)

None. At enrollment, women reported diet through a food frequency questionnaire, from which we computed three dietary pattern adherence scores: the Mediterranean diet, the Fertility diet, and the Profertility diet.

MAIN OUTCOME MEASURE(S)

The AFC was assessed with a transvaginal ultrasound performed on the third day of an unstimulated menstrual cycle or on the third day of a P withdrawal bleed.

RESULT(S)

Higher adherence to the three dietary patterns examined were unrelated to AFC. The multivariable adjusted AFC means and 95% confidence intervals for women in the highest compared with the lowest quartile of adherence score were 13.9 (13.0-14.9) and 13.5 (12.6-14.4) for the Mediterranean diet, 14.0 (13.2-14.9) and 13.5 (12.7-14.3) for the Fertility diet, and 12.5 (11.6-13.5) and 13.3 (12.5-14.2) for the Profertility diet.

CONCLUSION(S)

Dietary patterns were unrelated to AFC among a cohort of women presenting at a fertility center. Due to the limited and heterogeneous current evidence, it is important to evaluate this association in further studies, and in particular among women from the general population.

Do dietary intakes influence the rate of decline in anti-Mullerian hormone among eumenorrheic women? A population-based prospective investigation

BACKGROUND

Dietary intakes are suggested to affect age at menopause but associations between dietary factors and ovarian reserve reduction have not yet been investigated. We aimed to examine dietary intakes in relation to the rate of decline in anti-Mullerian hormone (AMH), an indicator of ovarian reserve, in a generally healthy cohort of women.

METHODS

This prospective investigation was conducted among 227 eumenorrheic women, aged 20-50 years, from the Tehran Lipid and Glucose study, who were followed over a mean of 16 years. AMH was measured twice, at baseline and the 5th follow-up examination cycle, and yearly rate of decline in AMH was calculated. Rapid decline in AMH was defined as the annual percent change AMH > 5.9%/year based on tertile 3 of the variable. Average usual dietary intakes were estimated using the food frequency questionnaires administered at the second, third, and the fourth follow-up examinations. After adjusting for potential covariates, the association between dietary factors and both risk of rapid decline in AMH and also annual percent decline of AMH (as a continuous variable) were examined using logistic regression and the Spearman correlation, respectively.

RESULTS

The baseline age of the participants and the median rate of decline in AMH were 37.2 years and was 5.7% yearly, respectively. The odds of rapid decline in AMH was reduced by 47% for dairy products (95% CIs = 0.36, 0.79; p = 0.002), 38% for milk (95% CIs = 0.41, 0.93; p = 0.020), and 36% for fermented dairy (95% CIs = 0.45, 0.93, p = 0.018) per one standard deviation (SD) increase in their dietary intakes. The odds of rapid decline in AMH was significantly reduced with higher intakes of fat, carbohydrate, protein, and calcium intakes from dairy sources, lactose and galactose. Annual rate of AMH decline was inversely correlated with dairy products, milk, fermented dairy, fruits, dairy carbohydrate, dairy fat, dairy protein, total calcium and dairy calcium, lactose and galactose, and positively correlated with organ meats.

CONCLUSION

Dairy foods consumption may reduce the rate of AMH decline in regularly menstruating women. Life style modification in terms of dietary advice may be considered as a preventive strategy for reduction in the rate of ovarian reserve loss.

Dietary factors and serum antimüllerian hormone concentrations in late premenopausal women

OBJECTIVE

To study the associations between dietary factors and circulating antimüllerian hormone (AMH) concentrations among late premenopausal women.

DESIGN

AMH concentrations were measured in serum samples collected at enrollment from 296 women (aged 35-45 years) in the Sister Study cohort. Usual dietary intakes in the past 12 months were assessed using a validated food frequency questionnaire. Dietary exposures of interest included macronutrients, dietary fat subtypes, fiber, and glycemic index. Multivariable linear regression was used to evaluate associations between dietary variables and serum AMH concentrations. We also used nutrient density models to examine isocaloric replacement of macronutrients.

SETTING

Not applicable.

PATIENTS

Women aged 35-45 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Serum AMH concentrations in nanograms per milliliter (ng/mL).

RESULTS

AMH concentrations were positively associated with percentage of energy from carbohydrates (β per 5% calories = 0.141 [95% CI 0.023, 0.259]; P trend = .019), and inversely associated with percentage of energy from fat (β per 5% calories = -0.152 [95% CI -0.299, -0.004]; P trend = .044). In analyses of dietary fat subtypes, AMH decreased with increasing monounsaturated fatty acids (P trend = .082) and polyunsaturated fatty acids (P trend = .043), particularly ω-6 fatty acids (P trend = .044), whereas no strong trend was observed for saturated fatty acids. Protein and alcohol intake were not strongly associated with AMH.

CONCLUSIONS

Our cross-sectional analyses in a sample of late premenopausal women suggest that dietary fat intake may be inversely associated with circulating AMH concentrations. Further research in prospective studies is warranted to evaluate dietary factors as potential modifiers of ovarian reserve.

Diet and female fertility: doctor, what should I eat?

Fecundity is the capacity to produce offspring. Identifying dietary factors that influence human fecundity is of major clinical and public health significance. This review focuses on the evidence from epidemiologic literature for the relationships between key nutritional factors and female reproductive potential. According to existing data, women trying to achieve pregnancy are encouraged to increase consumption of whole grains, omega-3 fatty acids, fish, and soy and to reduce consumption of trans fats and red meat. In addition, a daily multivitamin that contains folic acid before and during pregnancy may not only prevent birth defects, but also improve the chance of achieving and maintaining a pregnancy. In contrast, there is limited evidence supporting an association between vitamin D and human fecundity outcomes despite promising evidence from nonhuman studies. Questions for future research included the roles of other types of fat (especially omega-6 and monounsaturated fats) and protein (especially white meat and seafood) on female fertility; particular attention should also be paid to exposure to environmental contaminants in foods. Although much work remains, this review accrued best available evidence to provide practical dietary recommendations for women trying to conceive.

Testosterone-Associated Dietary Pattern Predicts Low Testosterone Levels and Hypogonadism

Obesity and low serum testosterone (T) levels are interrelated and strongly influenced by dietary factors, and their alteration entails a great risk of hypogonadism. Substantial evidence suggests a bidirectional relationship between nutrient metabolism (e.g., glucose, lipids, and iron) and T levels in men; however, T-related dietary patterns remain unclear. This study investigated the dietary patterns associated with serum total T levels and its predictive effect on hypogonadism and the body composition. Anthropometry, blood biochemistry, and food frequency questionnaires were collected for 125 adult men. Dietary patterns were derived using a reduced rank regression from 32 food groups. Overall prevalence rates of central obesity and hypogonadism were 48.0% and 15.7%, respectively. An adjusted linear regression showed that age, insulin, red blood cell (RBC) aggregation, and transferrin saturation independently predicted serum total T levels (all p < 0.01). The total T-related dietary pattern (a high consumption of bread and pastries, dairy products, and desserts, eating out, and a low intake of homemade foods, noodles, and dark green vegetables) independently predicted hypogonadism (odds ratio: 5.72; 95% confidence interval: 1.11‒29.51, p < 0.05) for those with the highest dietary pattern scores (Q4) compared to those with the lowest (Q1). Scores were also negatively correlated with the skeletal muscle mass (p for trend = 0.002) but positively correlated with the total body fat mass (p for trend = 0.002), visceral fat mass (p for trend = 0.001), and to a lesser extent, subcutaneous fat mass (p for trend = 0.035) after adjusting for age. Randomized controlled trials are needed to confirm that improvement in dietary pattern can improve T levels and reduce hypogonadism.

Dietary minerals, reproductive hormone levels and sporadic anovulation: associations in healthy women with regular menstrual cycles

Although minerals are linked to several reproductive outcomes, it is unknown whether dietary minerals are associated with ovulatory function. We hypothesised that low intakes of minerals would be associated with an increased risk of anovulation. We investigated associations between dietary mineral intake and both reproductive hormones and anovulation in healthy women in the BioCycle Study, which prospectively followed up 259 regularly menstruating women aged 18-44 years who were not taking mineral supplements for two menstrual cycles. Intakes of ten selected minerals were assessed through 24-h dietary recalls at up to four times per cycle in each participant. Oestradiol, progesterone, luteinising hormone (LH), follicle-stimulating hormone (FSH), sex-hormone-binding globulin and testosterone were measured in serum up to eight times per cycle. We used weighted linear mixed models to evaluate associations between minerals and hormones and generalised linear models for risk of anovulation. Compared with Na intake ≥1500 mg, Na intake <1500 mg was associated with higher levels of FSH (21·3 %; 95 % CI 7·5, 36·9) and LH (36·8 %; 95 % CI 16·5, 60·5) and lower levels of progesterone (-36·9 %; 95 % CI -56·5, -8·5). Na intake <1500 mg (risk ratio (RR) 2·70; 95 % CI 1·00, 7·31) and Mn intake <1·8 mg (RR 2·00; 95 % CI 1·02, 3·94) were associated with an increased risk of anovulation, compared with higher intakes, respectively. Other measured dietary minerals were not associated with ovulatory function. As essential minerals are mostly obtained via diet, our results comparing insufficient levels with sufficient levels highlight the need for future research on dietary nutrients and their associations with ovulatory cycles.

Enhanced insulin sensitivity in successful, long-term weight loss maintainers compared with matched controls with no weight loss history

Background:

Weight gain is associated with deterioration in metabolic health, whereas weight loss improves insulin sensitivity. This study assesses the impact of long-term, successfully maintained weight loss and weight-loss relapse on measures of insulin sensitivity and identifies factors that explain variability in insulin sensitivity.

Methods:

Women (20–45 years) were recruited into four groups: reduced-overweight/obese (RED, n=15); body mass index (BMI)-matched controls (stable low-weight, n=19), BMI⩽27 kg m⁻²; relapsed-overweight/obese subjects (REL, n=11); and BMI-matched controls (obese stable weight, n=11), BMI⩾27 kg m⁻². A 75 g oral glucose tolerance test determined fasting and 2 h plasma glucose and insulin. Homeostatic Model Assessment (HOMA-IR) and insulin sensitivity index (ISI_(0,120)) assessed insulin sensitivity. Anthropometric measurements, fasting resting metabolic rate (RMR) and respiratory quotient (RQ) were measured. Questionnaires and dietary intake were recorded, and physical activity was measured using accelerometers.

Results:

RED were more insulin sensitive, characterised by lower fasting (P=0.001) and 2 h insulin (P=0.003) levels compared with all other groups. There were no significant differences in dietary intake, sedentary, light and moderate activity, RMR or RQ in the RED compared with the other three groups. % Body weight (BW) lost (P<0.001), % BW regained (P<0.05), body fat %, light activity (P<0.05, only log HOMA), vigorous activity (P<0.05) and RQ (P<0.01) predicted 61.4% and 59.7% of variability in log HOMA and log ISI_(0,120), respectively, in multiple linear regression models.

Conclusion:

This study showed sustained enhanced insulin sensitivity in successful weight loss maintainers compared with BMI-matched controls with no weight loss history. Weight-loss-relapsed individuals were indistinguishable from controls. Weight loss itself was the strongest predictor of improved insulin sensitivity, whereas weight regain significantly predicted reduced insulin sensitivity. Weight-loss maintenance programs are essential to retaining metabolic benefits acquired through weight loss. Being physically active, reducing sedentary behaviour and, in particular, including small amounts of vigorous physical activity significantly predicted improved insulin sensitivity.

Dairy Food Intake Is Associated with Reproductive Hormones and Sporadic Anovulation among Healthy Premenopausal Women

BACKGROUND

Dairy food intake has been associated with infertility; however, little is known with regard to associations with reproductive hormones or anovulation.

OBJECTIVE

We investigated whether intakes of dairy foods and specific nutrients were associated with reproductive hormone concentrations across the cycle and the risk of sporadic anovulation among healthy women.

METHODS

We prospectively measured serum reproductive hormones ≤8 times/menstrual cycle for 2 cycles from 259 regularly menstruating women (mean age: 27.3 y). Dairy food intake was assessed via 24-h dietary recalls 4 times/cycle. Dairy food intakes were assessed by 1) total and low- and high-fat dairy products; 2) dairy nutrients, including fat, lactose, calcium, and phosphorus; and 3) dairy foods, including milk, cheese, butter, cream, yogurt, and ice cream categories. Weighted linear mixed models were used to evaluate associations between dairy nutrients or food intakes and hormone concentrations. Modified Poisson regression models with robust error variance were used to evaluate anovulation. Models were adjusted for age, body mass index, race, physical activity, Mediterranean diet score, total energy, protein, fiber, caffeine, and other hormones.

RESULTS

Each serving increase in total and low- and high-fat dairy foods and all increases in amounts of all dairy nutrients tested were associated with an ∼5% reduction in serum estradiol concentrations but were not associated with anovulation. Total and high-fat dairy food intakes were positively associated with serum luteinizing hormone concentrations. We observed associations between intakes of >0 servings of yogurt (RR: 2.1; 95% CI: 1.2, 3.7) and cream (RR: 1.8; 95% CI: 1.0, 3.2) and a higher risk of sporadic anovulation compared with no intake.

CONCLUSIONS

Our study showed associations between increasing dairy food and nutrient intakes and decreasing estradiol concentrations as well as between cream and yogurt intakes and the risk of sporadic anovulation. These results highlight the potential role of dairy in reproductive function in healthy women.

High carbohydrate intake from starchy foods is positively associated with metabolic disorders: a Cohort Study from a Chinese population

Starchy foods are the main sources of carbohydrates; however, there is limited information on their metabolic impact. Therefore, we assessed the association between carbohydrates from starchy foods (Carb-S) intakes and the metabolic disorders of metabolic syndrome (MetS) and hyperlipidemia. In this study, 4,154 participants from Northern China were followed up for 4.2 years. Carb-S included rice, refined wheat, tubers, and their products. Multivariable regression models were used to calculate risk ratios (RRs) for MetS and hyperlipidemia from Carb-S, total carbohydrates, and carbohydrates from other food sources (Carb-O). Receiver operating characteristic analysis was used to determine a Carb-S cut-off value. High total carbohydrate intake was associated with increased risks of MetS (RR: 2.24, 95% CI: 1.00–5.03) and hyperlipidemia (RR: 3.05, 95% CI: 1.25–7.45), compared with the first quartile. High Carb-S intake (fourth quartile) was significantly associated with MetS (RR: 1.48, 95% CI: 1.01–2.69) and hyperlipidemia (RR: 1.73, 95% CI: 1.05–3.35). No associations with Carb-O were observed. Visceral adiposity, triglyceride levels, and high-density lipoprotein cholesterol significantly contributed to the metabolic disorders. The Carb-S cut-off value was 220 g. Both high total carbohydrate and Carb-S intakes were associated with hyperlipidemia and MetS; Carb-S appears to contribute more to these disorders.