Independent effects of maternal obesogenic diets on offspring outcomes are acknowledged, but data on paternal and combined maternal-paternal obesity remain limited. We investigated independent and combined maternal-paternal effects of an obesogenic (OB) high-fat, high-sugar diet on offspring outcomes. Male (pat) and female (mat) rats were fed a control diet (CON) or OB diet for 5 weeks pre-mating. Four groups were established: matCON-patCON, matCON-patOB, matOB-patCON and matOB-patOB. Offspring outcomes included birth weight and naso-anal length, survival rates to weaning, weaning weight, retroperitoneal fat mass and plasma leptin. Mating success was reduced in OB-exposed fathers. Male and female offspring from mothers fed the OB diet had lower birth weights. In males, birth weights were further reduced in the matOB-patOB group. Combined maternal-paternal obesity was also associated with shorter body length and higher neonatal mortality in offspring of both sexes. Postnatal survival was lower with maternal obesity and worsened with combined maternal-paternal obesity. At weaning, male offspring exposed to maternal or combined maternal-paternal obesity showed increased body weight, adiposity and plasma leptin concentrations. In females, body weight at weaning was higher across all parental obesogenic diet groups, and increased adiposity and plasma leptin concentrations were observed in maternal and combined maternal-paternal obesity. Parental obesity had independent, combined and sex-specific effects on early-life outcomes, most severe with combined maternal-paternal obesity. These findings emphasise the interacting role of maternal and paternal nutrition in shaping early-life outcomes and highlight the need for research to determine effective strategies to optimise the health of both parents prior to conception.

The Cook Islands, a small Pacific nation, carries a high burden of obesity (75

Seaweed, a nutrient-dense and sustainable food source, holds promise for helping to meet growing global dietary protein demands. However, its complex cellular structure embeds protein within membranes and walls, making extraction challenging and limiting protein yields (1) . Seaweed has traditionally been consumed with minimal processing in relatively small quantities, such as 5-10 g daily in Asian diets (2,3) . The volume required for seaweed to serve as a meaningful protein source is relatively high, raising concerns about safety, digestibility, gastrointestinal tolerance, and sensory acceptability. The effects of large servings of minimally processed seaweed have not been examined in human studies. This study evaluated the impact of a minimally processed seaweed meal (SWM, containing ~150 g of seaweed) on postprandial plasma amino acid response, micronutrient bioavailability, safety, tolerance, and sensory acceptability in healthy adults. The hypothesis was that protein in the SWM would increase amino acid concentrations in the peripheral circulation compared to the control (CON) meal. In this single-blinded, randomized cross-over trial, 20 healthy adults (12 females, 8 males; aged 18-60 years, BMI 18-30 kg/m2) consumed either the SWM or a CON meal on separate days. Blood samples and questionnaires were collected at fasting and regular intervals for 4 hours, while urine was collected up to 24 hours post-consumption. Both meals were dumplings with identical ingredients, except seaweed was added to the SWM. It contained more protein (+3.75 g), carbohydrate (+10 g), fat (+2.35 g), energy (~318 kJ), and essential amino acids (EAAs) (+1.56 g). There was no difference between SWM and CON for plasma pooled essential amino acids (EAAs) peak concentration (1036.6± 144.0 vs. 1053.0± 160.5 µmol L −1 ; p=0.66) or incremental area under the curve (iAUC; p=0.65). However, SWM resulted in lower peak plasma concentrations of asparagine (p=0.02) and glutamine (p=0.03), and reduced iAUC for alanine (p=0.02), proline (p=0.01), and tyrosine (p=0.02). Plasma glucose, insulin, and triglyceride responses were similar between meals. Serum iodine concentration was higher following SWM (p=0.02). Urinary iodine peaked 2-4 hours after the SWM meal, declined by 24 hours, but stayed above baseline and was higher than CON (p<0.001). Urinary arsenic was higher at 24 hours in SWM vs. CON (p=0.05) but remained below safety limits. Gastrointestinal symptoms, including abdominal distension and belching, were more pronounced after SWM (treatment×time interaction: p=0.03 and p<0.001, respectively). Appetite-related responses, including hunger and satiation, were less favourable for SWM (main treatment effect: p<0.001), although no treatment×time interaction was observed. Intake of the SWM did not lead to differences in overall bioavailability of EAAs compared to CON, although some individual amino acid responses varied. The SWM resulted in less favourable gastrointestinal symptoms and satiety outcomes, which therefore suggests that meals containing a high proportion of minimally processed seaweed require further optimisation.

The developmental origins of health and disease (DOHaD) framework highlights the link between adverse early-life environments and later risk for non-communicable disease (NCDs). DOHaD research has primarily focused on maternal health and, more recently, paternal health. However, it is increasingly clear that investment in the adolescent window may afford the best opportunity to break the transgenerational cycle of NCDs. Data on DOHaD understanding in adolescents remains limited, and in the context of this article, there remains a paucity of research undertaken with adolescents in Oceania, particularly Pacific adolescents, who experience a disproportionately high NCD burden. NCDs represent a complex health issue and therefore multisectoral approaches and collaborative partnerships across different disciplines, health and social professions and communities is required. Due to the significance of DOHaD research and the importance of investing in our children and adolescents for the future, we developed a framework called Taumafa Kava to guide DOHaD-related research in Pacific communities across Oceania. This framework is based on a Tongan Taumafa Kava ceremony and it is an introduction to the cultural significance of the methysticum plant root (kava) and its relevance in highlighting a shared responsibility to serve Pacific Peoples well in DOHaD research. Furthermore, it is a call to action highlighting the importance of understanding the need to deliver DOHaD research that is inclusive of Pacific knowledges, cultures, languages, identities and contexts. This framework has been applied in a research project to showcase the potential for this approach to be utilised in DOHaD-related research in Pacific communities.

In Aotearoa New Zealand, approximately 1 in 3 adults and 1 in 8 children are classified as obese, with Māori and Pacific communities disproportionately affected (1) . While maternal nutrition has been extensively studied, paternal impacts and the combined effect of both parents’ obesogenic environments on offspring health remain underexplored (2) . The primary objective of this study is to characterise the metabolic phenotype of parent rats fed a High Fat High Sugar (HFHS) diet and investigate the birth characteristics of their offspring, from a factorial mating design. Eighty female and 40 male Sprague-Dawley rats were randomised to a standard chow diet (SD) (24% protein, 18% fat, 58% carbohydrates) or HFHS diet (Specialty Feeds SF23-120: 16% protein, 41% fat, 43% carbohydrates) for five weeks prior to mating. Females were then continued on their respective diets throughout pregnancy and lactation. Four mating combinations were established: SDmum-SDdad, SDmum-HFHSdad, HFHSmum-SDdad, and HFHSmum-HFHSdad. A subset of parents (n=38) underwent body composition assessments using dual-energy X-ray absorptiometry (DEXA). Additionally, a subgroup (n=23) was evaluated for metabolic profiles using Prometheon metabolic cages. Offspring birth weights and body lengths were recorded. The HFHS diet’s efficacy was confirmed in both male and female rats, with HFHS groups showing higher body weight (females: 327.1 g ± 19.7 vs. 288.2 g ± 20.1; males: 575.8 g ± 39.8 vs. 532.6 g ± 50.3; p < 0.05), greater fat percentage (females: 46.8% ± 5.6 vs. 29.2% ± 5.6; males: 40.5% ± 7.2 vs. 28.7% ± 6.8; p < 0.001), and a lower respiratory exchange ratio (RER) (females: 0.8108 ± 0.0275 vs. 0.8679 ± 0.0288; males: 0.8257 ± 0.0304 vs. 0.8759 ± 0.0266; p < 0.05) compared to the SD group. In male offspring, birth weights in HFHSmum-SDdad (6.3 g ± 0.9) and HFHSmum-HFHSdad (6.0 g ± 0.9) groups were significantly lower (p < 0.0001) than in SDmum-SDdad (6.980 g ± 0.7753) and SDmum-HFHSdad (7.0 g ± 0.7) groups. Birth weights were further reduced in HFHSmum-HFHSdad versus HFHSmum-SDdad (Mean Diff. = 0.3g; p < 0.05).Body lengths in HFHSmum-HFHSdad males were shorter (43.1 mm ± 3.2; p < 0.0001) compared to other groups (≥ 45.3 mm). Female offspring birth weights were lower in the HFHSmum-SDdad (5.8g ± 0.8) and HFHSmum-HFHSdad groups (5.8 g ± 0.9; p<0.0001) compared to the other groups (means ≥ 6.4g) but paternal HFHS diet had no additional effect on birth weight. As with males, body lengths in the HFHSmum-HFHSdad female offspring were significantly shorter (4 mm ± 3; p<0.0001) compared to all other groups (≥44mm). Parental HFHS diets synergistically reduce offspring birth length and weight, with stronger effects in males. These findings underscore the importance of inclusive dietary guidelines for both parents to reduce intergenerational obesity risk and support long-term health.

Achilles tendinopathy is characterized by deterioration of tissue integrity and biomechanical properties. Reduced tendon stiffness is detrimental to its function. Previous studies found that increased body mass is a risk factor for Achilles tendinopathy. We aimed to determine whether increasing the stiffness of damaged Achilles tendon by the collagen crosslinker genipin can improve early healing outcomes in an animal model of collagenase-induced tendinopathy, and whether the effect depends on body mass.Male and female Sprague-Dawley rats were allocated to normal diet (ND) or high-fat diet (HFD) at weaning. At 17 weeks, each sex and diet group was divided into three treatment groups (n = 15): collagenase (CT), collagenase-genipin (CT-GT), and genipin (GT). Collagenase and genipin were injected into the Achilles tendons; contralateral tendons served as controls. After 10 days, Achilles tendons were collected for biomechanical and histological evaluation.At the time of tendinopathy induction, animals fed HFD weighed on average, 14.5 % more than animals on ND. Biomechanical and histological changes characteristic of tendinopathy were observed in Achilles tendons of all animals treated with collagenase. Genipin had no effect on tendon biomechanical and histological properties: we found no differences between the GT and the control group, or between the CT-GT and the CT group.In conclusion, 1 mM genipin did not improve the biomechanical properties of tendinopathic Achilles, and had no effect on early tendon healing in this rat model of collagenase-induced Achilles tendinopathy, irrespective of animal sex and weight. This is an important pre-clinical finding and can be used to direct future research, and prevent possible research wastage. One potential future direction is exploring innovative delivery systems to maintain higher local concentrations of genipin, that may be required to realize the potential of this molecule in tendon healing.

Objective People with attentional problems are at increased risk of eating disorders. This paper aimed to systematically review and synthesize the existing evidence on stimulant medication in the management of patients with bulimia nervosa (BN) or anorexia nervosa (AN) with or without comorbid attention deficit hyperactivity disorder (ADHD). Method A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A protocol for the review was registered with Open Science Framework (OSF) Registry and critical appraisal of the literature was conducted using Joanna Briggs Institute (JBI) Critical Appraisal Tools. Results Thirteen articles met inclusion criteria including two quasi-experimental studies, one randomized controlled trial, four case series, and six case reports. 26 cases were included from studies and 32 from case series/reports. Only two cases from a single case report had a diagnosis of AN, while the remainder had BN. Stimulants included methylamphetamine, lisdexamfetamine, methylphenidate, dextroamphetamine sulphate and mixed amphetamine salt. In nearly all cases of BN there were reported reductions in eating disorder symptoms. The rates of adverse effects were high and included weight loss, decreased appetite, tachycardia, dry mouth, fatigue, insomnia, restlessness, nausea, bruxism, headache, palpitations, blood pressure changes, irritability, anxiety, depressed mood, and diaphoresis. Conclusion There is currently insufficient evidence to support the use of stimulant medications to treat symptoms of BN or AN. The authors recommend considering screening patients with BN for ADHD.

Adoptive immunotherapy with Epstein-Barr virus (EBV)-specific T cells is an effective treatment for relapsed or refractory EBV-induced post-transplant lymphoproliferative disorders (PTLD) with overall survival rates of up to 69%. EBV-specific T cells have been conventionally made by repeated stimulation with EBV-transformed lymphoblastoid cell lines (LCL), which act as antigen-presenting cells. However, this process is expensive, takes many months, and has practical risks associated with live virus. We have developed a peptide-based, virus-free, serum-free closed system to manufacture a bank of virus-specific T cells (VST) for clinical use. We compared these with standard LCL-derived VST using comprehensive characterization and potency assays to determine differences that might influence clinical benefits. Multi-parameter flow cytometry revealed that peptide-derived VST had an expanded central memory population and less exhaustion marker expression than LCL-derived VST. A quantitative HLA-matched allogeneic cytotoxicity assay demonstrated similar specific killing of EBV-infected targets, though peptide-derived EBV T cells had a significantly higher expression of antiviral cytokines and degranulation markers after antigen recall. High-throughput T cell receptor-beta (TCRβ) sequencing demonstrated oligoclonal repertoires, with more matches to known EBV-binding complementary determining region 3 (CDR3) sequences in peptide-derived EBV T cells. Peptide-derived products showed broader and enhanced specificities to EBV nuclear antigens (EBNAs) in both CD8 and CD4 compartments, which may improve the targeting of highly expressed latency antigens in PTLD. Importantly, peptide-based isolation and expansion allows rapid manufacture and significantly increased product yield over conventional LCL-based approaches.

OBJECTIVE:The authors sought to explore the role of iron supplementation in the management of neurodevelopmental disorders among children and youths. METHODS:A systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was undertaken. A subset of results was suitable for meta-analysis. The quality of the evidence and strength of the clinical recommendations were assessed by using the Grading of Recommendations, Assessment, Development, and Evaluation method, and critical appraisal was conducted with the Joanna Briggs Institute critical appraisal tools. RESULTS:Nine articles met inclusion criteria. These articles included studies of attention-deficit hyperactivity disorder (ADHD) (N=7), autism spectrum disorder (N=1), and Tourette's syndrome (N=1). Three randomized controlled trials evaluating iron supplementation for ADHD hyperactivity symptom severity (124 participants: placebo, N=56; supplement, N=68) met inclusion criteria for a meta-analysis. Effect sizes for the placebo and supplement groups were moderate (Cohen's d=0.76) and large (Cohen's d=1.70), respectively, although these differences were not significant. The impact of iron supplementation on inattentive ADHD symptom severity was examined in two trials (75 participants: placebo, N=31; supplement, N=44). Large, nonsignificant effect sizes were demonstrated for the placebo (Cohen's d=1.66) and supplementation (Cohen's d=3.19) groups. The quality of the evidence and strength of the clinical recommendations were considered very low. CONCLUSIONS:Further research is needed to examine the role of iron supplementation in the management of ADHD and neurodevelopmental disorders more generally. Additionally, iron supplementation comes with risks, including death in the case of overdose.

This study explored the perceptions of peer leaders participating in a peer-led physical activity (PA) initiative where student leaders conduct fitness classes for their peers. Thirty-eight participants aged 9-13 from four New Zealand elementary and middle schools were surveyed using an online questionnaire gathering both qualitative and quantitative data. Student leaders viewed the experience positively, despite the physical challenges involved, and many reported increased fitness or PA levels. Provision of regular school practice time, teacher input, and resources from the outside provider were key. The task of leading their peers placed the leaders in a supportive yet anxiety-provoking environment, which presented valuable opportunities to teach them resilience-building skills. To fully leverage the programme's potential impact, connections to a range of curriculum learning objectives could offer more meaningful learning experiences, including resilience building, generating understanding of the benefits of PA, and developing the skills involved in group work and leadership.

The Developmental Origins of Health and Disease (DOHaD) framework has highlighted the role of maternal and paternal health on disease risk in offspring and across generations. Although adolescence is increasingly recognised as a key DOHaD window where interventions may have the greatest impact in breaking the cycle of non-communicable diseases, data around the recognition of this concept in adolescents remain limited. Previous work by our group found that the understanding of DOHaD-related concepts among adolescents in New Zealand was low, including some adolescents showing disagreement with key DOHaD concepts. This qualitative study aimed to explore DOHaD perspectives and understandings among a group of adolescents who responded to the survey using semi-structured focus groups and interviews (n = 12). Four core themes were identified: 1. knowledge of DOHaD and DOHaD-related terminology; 2. understanding different life course windows for DOHaD interventions; 3. recognising that DOHaD-related information needs to be accessible for adolescents; and 4. the importance of developing context-specific resources for adolescents. Adolescents in this study indicated that they had not heard of DOHaD or related terminology. Although the majority recognised that there were many important life stages for potential interventions, there was a strong emphasis on adolescence as a key window of opportunity. Adolescents suggested that more could be done in schools to help promote awareness and understanding of DOHaD-related concepts during the later years of schooling. The development of future resources needs to be contextually specific for adolescents to ensure increased uptake of information during this important developmental window.

The Developmental Origins of Health and Disease (DOHaD) framework has highlighted the link between an adverse early life environment and later disease risk. There is an increasing focus on adolescents as the next generation of parents as DOHaD agents of change to break the disease cycle. However, DOHaD awareness in adolescents is key to enabling knowledge uptake and behavioural change, particularly in Pacific adolescents who have a higher non-communicable disease (NCD) burden. The present study investigated understanding of DOHaD-related concepts among Pacific, M & amacr;ori and other ethnic groups in New Zealand (ages 16-19 years, n = 209). Awareness of the term NCDs was low across all groups with awareness of the term DOHaD or the First 1000 Days lower in the Pacific group compared to others. Similarly, awareness of some key DOHaD concepts was low overall with some gender differences in response within ethnicity. Interestingly, adolescents' understanding that the early life nutritional environment can impact health across the life-course diminishes significantly with each advancing life-course stage. These results indicate that both education and healthcare DOHaD-related health promotion are lacking with a need for increased engagement with adolescents, particularly Pacific adolescents, to develop and communicate DOHaD content and messaging relevant to this demographic.

The developmental origins of health and disease (DOHaD) framework has highlighted the importance of the early life period on disease risk in later life with impacts that can span generations. A primary focus to date has been around maternal health and the ‘First Thousand Days’ as a key developmental window whereby an adverse environment can have lasting impacts on both mother and offspring. More recently, the impact of paternal health has gathered increasing traction as a key window for early life developmental programming. However, to date, adolescents, the next generation of parents, have attracted less attention as a key DOHaD window although many behavioural traits become entrained during adolescence and track into adulthood. This systematic review examined literature focused on identifying adolescent understanding of DOHaD concepts. Consistent across the eligible articles was that overall understanding of DOHaD-related concepts in adolescents was low. Three key themes emerged: 1. Individual-level awareness of DOHaD concepts (cognitive engagement and action of the adolescents themselves); 2. Interpersonal communication and social awareness of DOHaD concepts (cognitive engagement and communication of the DOHaD concepts to family and wider community); and 3. Health literacy and the promotion of adolescence as a key DOHaD life stage. These findings highlight the need to develop strategic approaches to increase DOHaD awareness that are not only appealing to adolescents but can also support sustained changes in health behaviour. Investment in today’s adolescents has the potential to act as a NCD ‘circuit breaker’ and thus will yield significant dividends for future generations.

Fecal microbiota transplantation (FMT) is a therapeutic intervention used to treat diseases associated with the gut microbiome. In the human gut microbiome, phages have been implicated in influencing human health, with successful engraftment of donor phages correlated with FMT treatment efficacy. The impact that gastrointestinal phages exert on human health has primarily been connected to their ability to modulate the bacterial communities in the gut. Nonetheless, how FMT affects recipients’ phage populations, and in turn, how this influences the gut environment, is not yet fully understood. In this study, we investigated the effects of FMT on the phageome composition of participants within the Gut Bugs Trial (GBT), a double-blind, randomized, placebo-controlled trial that investigated the efficacy of FMT in treating obesity and comorbidities in adolescents. Stool samples collected from donors at the time of treatment and recipients at four time points (i.e., baseline and 6 weeks, 12 weeks, and 26 weeks post-intervention), underwent shotgun metagenomic sequencing. Phage sequences were identified and characterized in silico to examine evidence of phage engraftment and to assess the extent of FMT-induced alterations in the recipients’ phageome composition. Donor phages engrafted stably in recipients following FMT, composing a significant proportion of their phageome for the entire course of the study (33.8 ± 1.2 https://bmjopen.bmj.com/content/9/4/e026174 .

Abstract Background: Fecal microbiota transplantation (FMT) is a therapeutic intervention used to treat diseases associated with the gut microbiome. In the human gut microbiome, phages have been implicated in influencing human health, with successful engraftment of donor phages correlated with FMT treatment efficacy. The impact that gastrointestinal phages exert on human health has primarily been connected to their ability to modulate the bacterial communities in the gut. Nonetheless, how FMT affects recipients’ phage populations, and in turn, how this influences the gut environment, is not yet fully understood. In this study, we investigated the effects of FMT on the phageome composition of participants within the Gut Bugs Trial (GBT), a double-blind, randomized, placebo-controlled trial that investigated the efficacy of FMT in treating obesity and comorbidities in adolescents. Stool samples collected from donors at the time of treatment and recipients at four time points (i.e., baseline and 6 weeks, 12 weeks, and 26 weeks post intervention), underwent shotgun metagenomic sequencing. Phage sequences were identified and characterized in silico to examine evidence of phage engraftment and to assess the extent of FMT-induced alterations in the recipients’ phageome composition. Results: Donor phages engrafted stably in recipients following FMT, composing a significant proportion of their phageome for the entire course of the study (33.8 ± 1.2% in females and 33.9 ± 3.7% in males). Phage engraftment varied between donors and donor engraftment efficacy was positively correlated with their phageome alpha diversity. FMT caused a shift in recipients’ phageome toward the donors’ composition and increased phageome alpha diversity and variability over time. Conclusions: FMT significantly altered recipients' phage and, overall, microbial populations. The increase in microbial diversity and variability is consistent with a shift in microbial population dynamics. This proposes that phages play a critical role in modulating the gut environment and suggests novel approaches to understand the efficacy of FMT in altering the recipient's microbiome. Trial registration: The Gut Bugs Trial was registered with the Australian New Zealand Clinical Trials Registry (ACTR N12615001351505). Trial protocol: The trial protocol is available at https://bmjopen.bmj.com/content/9/4/e026174.

BACKGROUND:The development of the breast for lactation occurs throughout pregnancy. It is unknown whether pregnancy complications resulting in poor fetal growth can affect breastfeeding (BF) success. OBJECTIVES:We examined whether fetal growth-related pregnancy complications were associated with earlier BF cessation and changes in the concentrations of human milk biomarkers of low milk production. METHODS:We used data from the Growing Up in Singapore Toward healthy Outcomes study (n = 954). Human milk concentrations of protein, lactose, citrate, sodium, potassium, and zinc at 3 wk postpartum were available for 180 mother-infant dyads. We examined the associations of fetal growth measures, including term infants born small-for-gestational-age (SGA) (<10th percentile), pregnancies complicated by fetal growth deceleration (second to third trimester fetal growth dropped between major centiles), elevated umbilical artery resistance (>90th percentile) or hypertensive disorders of pregnancy (HDP) with 1) risk of ceasing BF (Cox regression) and 2) concentrations of human milk components (weighted linear regression). RESULTS:Adjusting for maternal education, smoking exposure, BF intentions, and prepregnancy BMI (in kg/m2), individuals who delivered SGA infants and those with HDP were more likely to breastfeed for a shorter duration when compared to those with uncomplicated pregnancies {adjusted hazard ratio [95% confidence interval (CI)]: 1.45 (1.11, 1.89) and 1.61 (1.14, 2.29), respectively}; associations were nonsignificant for fetal growth deceleration and umbilical artery resistance. SGA was not associated with concentrations of human milk biomarkers, but compared to participants with uncomplicated pregnancies, milk produced by those with HDP contained lower zinc concentrations [adjusted β coefficient (95% CI): -0.56 mg/L (-1.08, -0.04) mg/L]. CONCLUSIONS:Individuals with HDP and those with SGA infants tend to breastfeed for a shorter duration; however, only HDP appear to be associated with biomarkers of compromised milk production. Further research and support are needed to help individuals with HDP and SGA achieve their BF goals. This trial was registered at clinicaltrials.gov as NCT01174875.

Context A maternal high-fat diet is thought to pose a risk to spermatogenesis in the progeny. Aims We tested whether a maternal high-fat diet would affect Sertoli cell expression of transcription factors (insulin-like growth factor I (IGF-I); glial-cell line-derived neurotrophic factor (GDNF); Ets variant 5 (ETV5)) and cell proliferation and apoptotic proteins, in the testis of adult offspring. Methods Pregnant rats were fed ad libitum with a standard diet (Control) or a high-fat diet (HFat) throughout pregnancy and lactation. After weaning, male pups were fed the standard diet until postnatal day 160. Males were monitored daily from postnatal day 34 to determine onset of puberty. On postnatal day 160, their testes were processed for morphometry and immunohistochemistry. Key results The HFat diet increased seminiferous-tubule diameter (P < 0.03), the numbers of Sertoli cells (P < 0.0001) and Ki-67-positive spermatogonia (P < 0.0006), and the areas immunostained for ETV5 (P < 0.0001), caspase-3 (P < 0.001) and Bcl-2 (P < 0.0001). By contrast, the HFat diet reduced the areas immunostained for IGF-I (P < 0.01) and GDNF (P < 0.0001). Conclusions A maternal high-fat diet alters the balance between spermatogonia proliferation and spermatid apoptosis. Implications A maternal high-fat diet seems to ‘program’ adult male fertility.