Obesity is strongly associated with insulin resistance (IR), along with mitochondrial dysfunction to metabolically active tissues and increased production of reactive O2 species (ROS). Foods rich in antioxidants such as wheat germ (WG), protect tissues from damage due to ROS and modulate some negative effects of obesity. This study examined the effects of WG supplementation on markers of IR, mitochondrial substrate metabolism and innate antioxidant markers in two metabolically active tissues (i.e. liver and heart) of C57BL/6 mice fed a high-fat–high-sucrose (HFS) diet. Male C57BL/6 mice, 6-week-old, were randomised into four dietary treatment groups (n 12 mice/group): control (C, 10 % fat kcal), C+10 % WG, HFS (60 % fat kcal) or HFS+10 % WG (HFS+WG). After 12 weeks of treatment, HFS+WG mice had significantly less visceral fat (−16 %, P=0·006) compared with the HFS group. WG significantly reduced serum insulin (P=0·009), the insulinotropic hormone, gastric inhibitory peptide (P=0·0003), and the surrogate measure of IR, homoeostatic model assessment of IR (P=0·006). HFS diet significantly elevated (45 %, P=0·02) cardiac complex 2 mitochondrial VO2, suggesting increased metabolic stress, whereas WG stabilised this effect to the level of control. Consequently, genes which mediate antioxidant defense and mitochondrial biogenesis (superoxide dismutase 2 (Sod2) and PPARγ coactivator 1-α (Pgc1a), respectively) were significantly reduced (P<0·05) in the heart of the HFS group, whereas WG supplementation tended to up-regulate both genes. WG significantly increased hepatic gene expression of Sod2 (P=0·048) but not Pgc1a. Together, these results showed that WG supplementation in HFS diet, reduced IR and improved cardiac mitochondrial metabolic functions.

A total of ten experimental diets with protein concentrations ranging from 154 to 400 g/kg and two lipid levels (46 and 85 g/kg) with identical energy densities were offered to 240 male Ross 308 broilers from 7 to 28 d post-hatch. Growth performance was monitored and nutrient utilisation (apparent metabolisable energy (AME), N-corrected AME (AMEn), AME daily intake, AME:gross energy ratios, N retention) was determined. The weight gain response of broiler chickens to dietary protein concentrations in diets containing high and low lipid levels was diverse, with the relevant quadratic regressions being significantly different (P<0·05). With low lipid levels, the predicted maximum weight gain of 1809 g/bird equated to 342 g/kg dietary protein, whereas, for high lipid levels the predicted maximum weight gain of 1694 g/bird equated to 281 g/kg dietary protein. AME was linearly correlated with dietary protein concentration but regressions in diets with different lipid content were not significantly different (P>0·05). AMEn was also linearly (P<0·0001) increased with dietary protein concentrations but regressions in diets with low and high lipid content were significantly different (P<0·03). Carcass protein content increased linearly with dietary protein content in diets containing high lipid concentrations (r 0·933, P<0·0001); by contrast, this relationship was quadratic (R2=0·93, P<0·0001) in diets with low lipid levels. In conclusion, predictably, the effects of dietary protein concentrations on broiler performance were profound; however, the impact of dietary protein on performance in broiler chickens was modified by dietary lipid concentrations.

Vitamin D deficiency is a global public health concern. Studies of serum 25-hydroxyvitamin D (25(OH)D) determinants in young women are limited and few include objective covariates. Our aims were to define the prevalence of vitamin D deficiency and examine serum 25(OH)D correlates in an exploratory study of women aged 16–25 years. We studied 348 healthy females living in Victoria, Australia, recruited through Facebook. Data collected included serum 25(OH)D assayed by liquid chromatography-tandem MS, relevant serum biochemistry, soft tissue composition by dual-energy X-ray absorptiometry, skin melanin density, Fitzpatrick skin type, sun exposure using UV dosimeters and lifestyle factors. Mean serum 25(OH)D was 68 (sd 27) nmol/l and 26 % were vitamin D deficient (25(OH)D <50 nmol/l). The final model explained 56 % of 25(OH)D variance. Serum sex hormone-binding globulin levels, creatinine levels, sun exposure measured by UV dosimeters, a positive attitude towards sun tanning, typically spending >2 h in the sun in summer daily, holidaying in the most recent summer period, serum Fe levels, height and multivitamin use were positively associated with 25(OH)D. Fat mass and a blood draw in any season except summer was inversely associated with 25(OH)D. Vitamin D deficiency is common in young women. Factors such as hormonal contraception, sun exposure and sun-related attitudes, as well as dietary supplement use are essential to consider when assessing vitamin D status. Further investigation into methods to safely optimise vitamin D status and to improve understanding of the impact of vitamin D status on long-term health outcomes is required.

Fe fortification of wheat flour was proposed in Haiti to combat Fe deficiency, but Fe bioavailability from fortificants has never been investigated in Haitian women or preschool children, two key target groups. We aimed to investigate the bioavailability of ferrous fumarate (FeFum), NaFeEDTA and their combination from fortified wheat flour. We recruited twenty-two healthy mother–child pairs in Port au Prince, Haiti, for an Fe-absorption study. We administered stable Fe isotopes as FeFum or NaFeEDTA individually in low-extraction wheat flour bread rolls consumed by all participants in a randomised, cross-over design. In a final, identical meal, consumed only by the women, FeFum+NaFeEDTA was administered. We measured Fe absorption by using erythrocyte incorporation of stable isotopes 14 d after consumption of each meal, and determined Fe status, inflammatory markers and Helicobacter pylori infection. Fe absorption (geometric mean was 9·24 (95 % CI 6·35, 13·44) and 9·26 (95 % CI 7·00, 12·31) from FeFum and 13·06 (95 % CI 9·23, 19·10) and 12·99 (95 % CI 9·18, 18·39) from NaFeEDTA in mothers and children, respectively (P<0·05 between compounds). Fe absorption from FeFum+NaFeEDTA was 11·09 (95 % CI 7·45, 17·34) and did not differ from the other two meals. H. pylori infection did not influence Fe absorption in children. In conclusion, in Haitian women and children, Fe absorption from NaFeEDTA was 40 % higher than from FeFum, and the combination FeFum+NaFeEDTA did not significantly increase Fe absorption compared with FeFum alone. In the context of Haiti, where the high costs of NaFeEDTA may not be affordable, the use of FeFum at 60 mg Fe/kg flour may be a preferable, cost-effective fortification strategy.

Although breakfast consumption is widely considered to be an important component of a healthy lifestyle, few UK studies have examined differences in nutrient intakes between breakfast consumers and breakfast skippers among children and adolescents. We investigated associations between breakfast skipping in 4–18-year-olds and their nutrient intakes using data from the UK’s National Diet and Nutrition Survey Rolling Programme. Dietary data were derived from 4-d estimated food diaries of 802 children aged 4–10 years and 884 children aged 11–18 years (1686 in total). Daily nutrient intakes of children with different breakfast habits were compared by one-way ANCOVA adjusting for relevant covariates (sex, age, ethnicity, equivalised household income and BMI). Within-person analysis was carried out on children with an irregular breakfast habit (n 879) comparing nutrient intakes on breakfast days with those on non-breakfast days using repeated measures ANCOVA. We observed that the overall nutritional profile of the children in terms of fibre and micronutrient intake was superior in frequent breakfast consumers (micronutrients: folate, Ca, Fe and I (P<0·01)) and, for the 4–10 years age group, on breakfast days (micronutrients: folate, vitamin C, Ca and I (P<0·01)). Also, significantly higher proportions of breakfast-consuming children met their reference nutrient intakes of folate, vitamin C, Ca, Fe and I compared with breakfast skippers (χ2 analysis, P<0·001). Our study adds to the body of data linking breakfast consumption with higher quality dietary intake in school-age children, supporting the promotion of breakfast as an important element of a healthy dietary pattern in children.

Advancing age increases the risk for diseases and health concerns like cognitive decline, constituting a major public health challenge. Lifestyle, especially healthy diet, affects many risk factors related to chronic diseases, and thus lifestyle interventions among older adults may be beneficial in promoting successful ageing. We completed a randomised 2-year multi-domain lifestyle intervention trial aiming at prevention of cognitive decline among 631 participants in the intervention and 629 in the control group, aged 60–77 years at baseline. Dietary counselling was one of the intervention domains together with strength exercise, cognitive training and management of CVD risk factors. The aim of this paper was to describe success of the intervention – that is, how an intervention based on national dietary recommendations affected dietary habits as a part of multi-intervention. Composite dietary intervention adherence score comprising nine distinct goals (range 0–9 points from none to achieving all goals) was 5·0 at baseline, and increased in the intervention group after the 1st (P<0·001) and 2nd (P=0·005) year. The difference in change compared with the control group was significant at both years (P<0·001 and P=0·018). Intake of several vitamins and minerals decreased in the control group but remained unchanged or increased in the intervention group during the 2 years. Well-targeted dietary counselling may prevent age-related decline in diet quality and help in preventing cognitive decline.

The adverse effect of red meat consumption on the risk for CVD is a major population health concern, especially in developing Hispanic/Latino countries in which there are clear trends towards increased consumption. This population-based case–control study examined the associations between total, processed and unprocessed red meat intakes and non-fatal acute myocardial infarction (MI) in Costa Rica. The study included 2131 survivors of a first non-fatal acute MI and 2131 controls individually matched by age, sex and area of residence. Dietary intake was assessed with a FFQ. OR were estimated by using conditional logistic regression. Higher intakes of total and processed red meat were associated with increased odds of acute MI. The OR were 1·31 (95 % CI 1·04, 1·65) and 1·29 (95 % CI 1·01, 1·65) for the highest quintiles of total red meat (median: 110·8 g or 1 serving/d) and processed red meat intake (median: 36·1 g or 5 servings/week), respectively. There were increasing trends in the odds of acute MI with higher total (P trend=0·01) and processed (P trend=0·02) red meat intakes. Unprocessed red meat intake was not associated with increased odds of acute MI. Substitutions of 50 g of alternative foods (fish, milk, chicken without skin and chicken without fat) for 50 g of total, processed and unprocessed red meat were associated with lower odds of acute MI. The positive association between red meat intake and acute MI in Costa Rica highlights the importance of reducing red meat consumption in middle-income Hispanic/Latino populations.

Dietary indices have been related to risk for type 2 diabetes (T2D) predominantly in white populations. The present study evaluated this association in the ethnically diverse Multiethnic Cohort and examined four diet quality indices in relation to T2D risk, homoeostatic model assessment-estimated insulin resistance (HOMA-IR) and biomarkers of dyslipidaemia, inflammation and adipokines. The T2D analysis included 166 550 white, African American, Native Hawaiian, Japanese American and Latino participants (9200 incident T2D cases). Dietary intake was assessed at baseline using a quantitative FFQ and T2D status was based on three self-reports and confirmed by administrative data. Biomarkers were assessed about 10 years later in a biomarker subcohort (n 10 060). Sex- and ethnicity-specific hazard ratios were calculated for the Healthy Eating Index-2010 (HEI-2010), the alternative HEI-2010 (AHEI-2010), the alternate Mediterranean diet score (aMED) and the Dietary Approaches to Stop Hypertension (DASH). Multivariable-adjusted means of biomarkers were compared across dietary index tertiles in the biomarker subcohort. The AHEI-2010, aMED (in men only) and DASH scores were related to a 10–20 % lower T2D risk, with the strongest associations in whites and the direction of the relationships mostly consistent across ethnic groups. Higher scores on the four indices were related to lower HOMA-IR, TAG and C-reactive protein concentrations, not related to leptin, and the DASH score was directly associated with adiponectin. The AHEI-2010 and DASH were directly related to HDL-cholesterol in women. Potential underlying biological mechanisms linking diet quality and T2D risk are an improved lipid profile and reduced systemic inflammation and, with regards to DASH alone, an improved adiponectin profile.