While short-term surgical outreach trips improve access to care in low- and middle-income countries (LMIC), there is rising concern about their long-term impact. In response, many organizations seek to incorporate capacity building programs into their outreach efforts to help strengthen local health systems. Although leading organizations, like the World Health Organization (WHO), advocate for this approach, uniform guidelines are absent.We performed a systematic review, using search terms pertaining to capacity building guidelines during short-term surgical outreach trips. We extracted information on authorship, guideline development methodology, and guidelines relating to capacity building. Guidelines were classified according to the Global-QUEST framework, which outlines seven domains of capacity building on surgical outreach trips. Guideline development methodology frequencies and domain classifications frequencies were calculated; subsequently, guidelines were aggregated to develop a core guideline for each domain.A total of 35 studies were included. Over 200 individual guidelines were extracted, spanning all seven framework domains. Guidelines were most frequently classified into Coordination and Community Impact domains and least frequently into the Finance domain. Less than half (46%) of studies collaborated with local communities to design the guidelines. Instead, guidelines were predominantly developed through author trip experience.As short-term surgical trips increase, further work is needed to standardize guidelines, create actionable steps, and promote collaborations in order to promote accountability during short-term surgical outreach trips. Despite remarkable improvements in global health, global surgical care has historically been neglected. The field has gained more attention as the surgical global burden of disease surpasses that of HIV/AIDS, tuberculosis, and malaria combined , 2. ThisTo counteract potential negative impacts, a paradigm shift toward a “diagonal” trip model is underway in response to the criticism of this traditionally “vertical approach,” which focuses on service delivery and specific diseases and typically operates outside the local healthcare system Fig.  13]. Th. Th13]. Given these benefits, building surgical capacity in LMICs is a frequently cited goal by organizations such as the World Health Organization (WHO), several Lancet Commissions such as the Lancet Commission on Global Surgery , 4, 15, Consensus regarding capacity building activities has been described for non-surgical outreach trips by DeCamp and colleagues, who outline seven core guidelines on ethics and clinical care . The litWe conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify literature describing capacity building guidelines during short-term surgical outreach trips. We did not register the protocol publicly. We designed explicit search algorithms and queried PubMed, Web of Science, Embase, and ProQuest. Each database algorithm included “capacity building,” “guidelines,” and “outreach trips” along with their synonyms and database-specific search terms (Appendix 1). We reviewed the references of included studies  and carrThere was no publication date or surgical sub-specialty restrictions. Exclusion criteria included trips without a surgical focus and long-term partnerships (defined as longer than eight weeks) . All stuAfter screening, we performed a quality assessment of eligible articles using the Appraisal of Guidelines Research and Evaluation—Recommendations Excellence (AGREE-REX) tool. We used this tool to appraise each guideline by measuring quality within three domains: clinical applicability, values and preferences, and feasibility , 25. OnlWe uploaded results onto Covidence, a Cochrane-sanctioned application for the screening and analysis of articles in systematic reviews. One author conducted the initial screening of titles and abstracts (CL). Two authors next conducted full text reviews of the remaining literature independently (CL and MM) and settled disputes during a research meeting, with a third author (LMS) available to settle discrepancies.We collected basic information about each included article, including authorship, guideline development methodology, any capacity building definition provided, and surgical specialty (if noted) of the trip. Each author list was analyzed for first author and then all author locations (or listed affiliations) to capture prevalence of LMIC authorship. We collected each paper’s methodology for guideline development and then grouped by methodology . We identified capacity building-related guidelines from each article and then classified each guideline by the Global-QUEST Capacity Building Framework and Operational Blueprint . This frAfter classifying all eligible guidelines into each domain, as seen in Table The initial search yielded 3564 articles; 145 duplicates were removed. In total, 35 articles were included Fig. . All incNone of the first authors were from LMICs, but ten 29%) studies included authors from LMICs in their author list. Nearly half of the studies  noted their guidelines, and best practices were created in collaboration with local stakeholders. When grouped by methodology  studies) and the least frequent was Finance, with components from nine (25%) studies , 57, 58.partnerships with the local hospital, local organizations and government agencies, and community health workers is crucial for capacity building initiative implementation.The establishment of bidirectional and long-term Professional development opportunities should be a focus of short-term surgical outreach trips, prioritizing sustained mentorship and peer education.governance and may not practice outside scope.Surgical outreach organizations and volunteers must comply and cooperate with local Community impact begins with a pre-trip needs assessment, includes continual outcome collection, and is contingent on successive trips to one location.finances are required, with a goal of slowly tapering funding reliance to local hospitals as the results of capacity building initiatives replace the need for trips.Flexible and reliable culture, norms, and resources should be demonstrated throughout all components of trip planning, duration, and sustained partnerships.Respect for local Coordination of teams, continuity of care, and academic activities should be driven by local needs and priorities.Extracted guidelines focusing on capacity building spanned all seven domains of the Global-QUEST framework, seen in Table Concerns regarding the impact of short-term surgical outreach trips have prompted discussions about, and inclusion of, capacity building initiatives as part of outreach trips. The traditional vertical approach to surgical aid has been criticized for a host of shortcomings, not only related to discontinuity of care for patients and a lack of emphasis on the development of local providers and health systems, but for perpetuation of power imbalances between LMIC and HICs and undertones of neocolonialism. While many leading organizations advocate for the incorporation of capacity building as part of a shift toward a more diagonal approach, there is a lack of consensus guidelines for how best to carry this out and how to move past the constraints of short-term surgical aid. In this review, we identified primarily manuscripts with descriptive or anecdotal recommendations and consolidated the recommendations into capacity building domains. These recommendations were found to span all seven domains of the applied capacity building framework, but there is a further need to ensure standardization and to promote accountability during short-term surgical outreach trips.In our analysis we found a lack of representation of LMIC voices guiding these discussions despite the known importance of cultural and setting-specific contextualization. Although many recommendations identified in this study noted the importance of inclusion of local leaders and personnel in capacity building activities and trip planning, only about half of the manuscripts captured by this study included authors from LMICs in their author list. This illustrates the concern of “parachute” or “helicopter research” dominating capacity building guidelines for LMICs , 61. SucOur analysis further supports the importance of local leadership in the development of guidelines and an awareness and respect for cultural contextualization. Additionally, there were no manuscripts which field tested or validated their guidelines. Current recommendations for guideline development and consensus building, as outlined by the WHO, suggest the development of a systematic search for evidence, inclusion of external reviews, and incorporation of community attributes –65. AdapWhen examining which capacity building domains were represented, culture and community domains were identified in nearly all guidelines. This finding is reinforced by a number of recent surveys of providers during outreach trips, where local and visiting care team providers most commonly highlighted knowledge of local culture as a necessary skill for visiting providers , 69. PreGuideline components in the finance domain were least commonly published, with only nine (25%) noting the importance of exploring new funding models to promote local health system revenue independence. This represents an area for research and guideline creation, especially as recent literature suggests that funding surgical scale-up, while initially a larger financial investment, is ultimately cost-effective . InvestiWhile many efforts to include capacity building during outreach trips were present in this study, actionable steps were noticeably missing. The majority of guidelines were presented descriptively as best practices, with two guidelines presented as manuals or checklists , 39. ImpThe findings of this study should be viewed in light of their limitations. As a review of current capacity building guidelines, we did not pilot test the guidelines presented. Furthermore, there may be a publication bias present. Guidelines and recommendations presented here may not capture all guidelines used or followed by outreach organizations, and the studies included represent a small proportion of trips conducted worldwide . FurtherIn conclusion, current guidelines for surgical outreach trips span all domains of capacity building, but there is a discrepancy in frequency of domain representation, guidelines are primarily anecdotal in nature, and there is limited input from LMIC authors and communities. As surgical outreach trips continue to increase, further work is needed to create standardized, actionable, and measurable guidelines in order to promote and unify best capacity building practices during these trips.


The COVID-19 pandemic resulted in widespread school closures, reducing access to school meals for millions of students previously participating in the US Department of Agriculture (USDA) National School Lunch Program (NSLP). School-prepared meals are, on average, more nutritious than home-prepared meals. In the absence of recent data measuring changes in children’s diets during the pandemic, this article aims to provide conservative, back-of-the-envelope estimates of the nutritional impacts of the pandemic for school-aged children in the United States. We used administrative data from the USDA on the number of NSLP lunches served in 2019 and 2020 and nationally representative data from the USDA School Nutrition and Meal Cost Study on the quality of school-prepared and home-prepared lunches. We estimate changes in lunchtime calories and nutrients consumed by NSLP participants from March to November 2020, compared to the same months in 2019. We estimate that an NSLP participant receiving no school meals would increase their caloric consumption by 640 calories per week and reduce their consumption of nutrients such as calcium and vitamin D. Because 27 to 78 million fewer lunches were served per week in March–November 2020 compared to the previous year, nationally, students may have consumed 3 to 10 billion additional calories per week. As students return to school, it is vital to increase school meal participation and update nutrition policies to address potentially widening nutrition disparities. School meals are a critical source of nutrition for millions of children and adolescents across the United States (US). Prior to the COVID-19 pandemic, the US Department of Agriculture (USDA) National School Lunch Program (NSLP) and School Breakfast Program served approximately 30 million lunches and 15 million breakfasts daily ,3. SchooThe COVID-19 pandemic resulted in widespread school closures, forcing schools to rapidly innovate to maintain student access to emergency meals  . Many ofThe pandemic led to major changes in children’s daily lives, including restricted opportunities to leave the home due to lockdowns and school closures, changes in family income due to job loss and illness, and increased stress. These and other factors may have contributed to changes in children’s dietary behaviors. Several recent studies focused on diet quality among school-aged children in the US, Europe, Asia, and South America have found the pandemic was associated with changes in eating habits ,14,15,16In this article, we estimate how loss of school-prepared meals may have impacted caloric and nutrient intake among students from low-income US households and discuss evidence-based strategies to offset the potentially harmful effects of the pandemic. In the absence of recent data measuring changes in child diet quality during the pandemic, this article serves as a thought experiment, providing conservative, back-of-the-envelope estimates of the nutritional impacts of the pandemic that can help guide future research and practice.We compared USDA meal reimbursement administrative data from March to November 2019 and 2020 to estimate the shortfall in the number of school-prepared lunches served . Meal reAll the data used in this analysis are available for public use and do not contain any personally identifying information. As this study did not meet the definition of human subjects research according to federal regulations (45 CFR 46), institutional review board approval was not required.On average, students who eat lunch prepared at home consume 128 additional calories compared to students who eat school-prepared lunch . If, durAt the national level, 27 to 78 million fewer school-prepared lunches per week (or 107 to 310 million fewer school-prepared lunches per month) were served between March and November 2020 compared to the same period in 2019.  The gap Because school-prepared lunches differ in quality than those prepared at home, we also estimate an increase in consumption of some nutrients that dietary guidelines recommend be consumed in moderation  and a decrease in the consumption of some nutrients that dietary guidelines recommend be consumed in greater quantities .Our back-of-the-envelope estimates indicate that the loss of school-prepared lunches during the pandemic may have resulted in considerable excess calorie consumption among students from low-income US households. Assuming 55% of lunches that would have otherwise been served in schools were replaced with emergency meals meeting NSLP standards, and the other 45% were replaced with home-prepared meals, excess weekly caloric consumption may have increased by up to 10 billion calories—the caloric equivalent of US children consuming nearly 41 million additional candy bars each week. The per-student daily increase of 128 calories associated with eating a home-prepared, rather than school-prepared lunch, if sustained, is likely sufficient to result in excess weight gain. Previous research suggests that 110–165 daily excess calories result in excess weight gain over a 10 year period among US children . Recent Approximately 18.5% of US children and adolescents are obese, and there are significant disparities by race, ethnicity, and socioeconomic status . ChildhoOur findings also suggest that the pandemic-related loss of school lunches may have reduced the intake of key nutrients such as calcium and vitamin D, which are important for growth and development . Those sThese models were designed to provide conservative estimates of how school closures may impact US student diet quality based on the best available evidence. There are currently no reliable national data that show the percent of schools that have taken advantage of USDA COVID-19 nutrition standard waivers, the nutritional quality of meals families have prepared at home since March 2020, or the percent of meals that have gone entirely unreplaced. These data will be critical to inform future research.Our analyses using SNMCS data provide a conservative estimate of changes in dietary intake due to school closures; however, our approach had some limitations. First, we assumed that emergency meals were of the same nutritional quality as NSLP meals. However, nationwide COVID waivers allowed schools to serve emergency meals of lower nutritional quality than those captured in SNMCS . A case Second, we assumed that lunches prepared at home during the pandemic were of the same quality as lunches previously packed at home and brought to school. Evidence, however, suggests that students’ diet quality on weekends or during summer, when consuming lunches at home, is worse than both the quality of lunches prepared by schools or lunches packed at home and brought to school ,31,32,33Third, we assumed that students who would have participated in NSLP on a typical school day had consistent access to meals at home during the pandemic. Prior studies show, however, that during school closures , food insecurity rises . TherefoFourth, estimates focus on lunch and do not account for breakfast, supper, or snacks . ChildreFinally, NSLP meal guidelines differ by grade to reflect differences in nutritional needs between younger and older children. Meals served under pandemic waivers were not required to meet the same grade-specific nutrition standards . For exaThese limitations contribute to imperfect projections; however, our conservative approach has, if anything, underestimated the negative impact of COVID on dietary intake. We do not use advanced statistical methods to calculate changes in diet quality, but rather aim to provide back-of-the-envelope estimates on which future analyses can build.Without policies to address the potential negative health impacts of long-lasting school closures, children may continue to grapple with the effects of weight gained during the pandemic even after schools reopen. Mitigating this damage may require stronger nutrition standards than are currently in effect for school meals and out-of-school meals. For example, during normal school closures , many meals are distributed through the Summer Food Service Program (SFSP), which has lower nutrition standards than NSLP ,40 Figu. SFSP nuLearning from food distribution successes during the pandemic may streamline school meal access during future closures. Schools participating in CEP were able to transition particularly smoothly to distributing emergency meals at the beginning of the pandemic. For example, some CEP schools automatically began sending free meals to all students at home, and all students in CEP schools were eligible for P-EBT benefits . AdditioWhile this study focused on changes in diet quality among US children, emerging evidence suggests that school closures and lockdowns may have had similar negative effects on diet quality among children in other countries ,13,14,15School meals play a critical role in students’ dietary quality, now more than ever. It is vital that we implement evidence-based school nutrition policies to offset potential harmful consequences of the pandemic.


Proton radiation therapy is a radiation oncology innovation expected to produce superior health-related quality of life (HRQoL) outcomes for children with cancer, compared to conventional photon radiation therapy. The review aim is to identify if clinical evidence exists to support the anticipated HRQoL improvements for children receiving proton radiation therapy. HRQoL outcomes of 1986 childhood cancer survivors are described. There is insufficient quality evidence to compare HRQoL outcomes between proton and photon radiation therapy. Therefore, the current state of the literature does not conclude that proton radiation therapy produces superior HRQoL outcomes for childhood cancer survivors. Despite recommendations, no evidence of routine HRQoL assessment using patient-reported outcomes in paediatric radiation oncology are identified. Further rigorous collection and reporting of HRQoL data is essential to improve patient outcomes, and to adequately compare HRQoL between radiation therapy modalities.n = 24) described outcomes for children with a central nervous system (CNS) tumour, four studies reported outcomes for children with a non-CNS tumour, and two studies combined CNS and non-CNS diagnoses within a single cohort. No studies analysed routine HRQoL collection during paediatric radiation oncology clinical practice. There is insufficient quality evidence to compare HRQoL outcomes between XRT and PRT. Therefore, the current state of the literature does not conclude that PRT produces superior HRQoL outcomes for childhood cancer survivors. Standardised clinical implementation of HRQoL assessment using patient-reported outcomes is recommended to contribute to improvements in clinical care whilst assisting the progression of knowledge comparing XRT and PRT.Paediatric cancer patients have a risk of late side effects after curative treatment. Proton radiation therapy (PRT) has the potential to reduce the incidence and severity of toxicities produced by conventional photon radiation therapy (XRT), which may improve the health-related quality of life (HRQoL) in children. This systematic review aimed to identify the evidence of HRQoL outcomes in childhood cancer survivors following XRT and PRT. Medline, Embase, and Scopus were systematically searched. Thirty studies were analysed, which described outcomes of 1986 childhood cancer survivors. Most studies ( Radiation therapy (RT) is used to provide treatment for paediatric cancers, often in combination with surgery, chemotherapy, and/or immunotherapy. Whilst multimodal curative intent treatments increase the probability of cures, it comes with an added risk of late side effects . Common Late effects of RT are associated with poor health-related quality of life (HRQoL) ,5. HRQoLProton radiation therapy (PRT) is increasingly used in paediatric radiation oncology . The uniRadiobiological modelling and initial clinical evidence demonstrate the advantages of using PRT to improve health outcomes in paediatric cancer patients ,14,15; hThis systematic review was conducted in accordance with preferred reporting items for systematic reviews and meta-analysis (PRISMA) 2020 guidelines . The revStudies were included if they were peer-reviewed, original research articles published in the English language, if a validated patient-reported outcomes tool was used to measure quality of life, and if participants were children diagnosed with cancer between ages 0 to 21 years . StudiesTwo authors (MD and MS) performed independent screening of title and abstracts after removal of duplicate records, followed by full-text assessment for inclusion. In situations where agreement for inclusion could not be reached, consensus was achieved by inviting additional authors for decision making (EB and NP). Two authors (MD and MS) performed quality assessment for all included studies using the 14 item QualSyst quantitative checklist  Supplem. Each crA total of 19 studies analyse HRQoL after XRT, and 10 studies analyse HRQoL after PRT. One study includes survivors treated with XRT or PRT . Yock etTwenty-four articles capture HRQoL in survivors of paediatric CNS tumours following RT see . A totalThree studies investigate the effect of socioeconomic status (SES) on the HRQoL of children treated for a CNS tumour with RT ,26,43. NOne study compares the HRQoL of patients with craniopharyngioma following XRT or PRT . At 1 anThree studies found that the self-reported HRQoL is worse for patients with brain tumours requiring RT than patients not requiring RT ,43,45. MThe reporting of RT variables, such as prescribed dose and fractionation, treatment modality, and treatment field extent, is highly variable. Kamran et al. (2018) found that survivors who have a whole posterior fossa boost have greater improvements over time in parent–proxy reported HRQoL than survivors who have a tumour bed boost, but there is no differences between the self-reported HRQoL . KuhlthaThe PedsQL Generic Core score, version 4.0, was used in 22 of the total 30 studies. A total of 19 studies report the PedsQL total core score. Two studies are excluded for further analysis, as patients are described as ‘post diagnosis’, and could not definitively be placed on a timeline post-RT. Two studies include a directly overlapping cohort, so the study of highest quality assessment is included in our analysis. One study is excluded from analysis as it includes patients of both CNS and non-CNS tumour sites, and another is excluded as it is the only eligible PedsQL study describing a non-CNS tumour cohort. PedsQL HRQoL scores for survivors of a CNS childhood cancer appear to improve with increased time from treatment, however due to the inconsistency in measurement points and variable patient characteristics, statistical analysis and/or regression could not be performed to compare the outcomes of XRT and PRT. Of the studies that collected self-report and parent–proxy report outcomes for the same cohort, parent–proxy reports are lower than the child self-report, and further from the PedsQL normative population score.Three longitudinal and one cross-sectional study are identified with survivors treated for a non-CNS cancer see  33,37,4,49. HarrTwo studies combine several diagnoses  into a single cohort for cross-sectional analyses see  29,38],,38,29,38To the best of our knowledge, this is the first systematic review identifying the patient-reported HRQoL following XRT and PRT for childhood cancer survivors treated after the year 2000. Based on the current evidence, a difference cannot be identified in HRQoL during or after RT, between XRT and PRT. This is a somewhat unexpected finding, and is likely due to the variability in patient characteristics, diagnoses, treatment regimens, and length of follow-up in the included studies of both modalities.n = 25, n = 9) [Five longitudinal studies report that HRQoL improves with time after treatment ,33,37,44, n = 9) ,40, and,The inconsistent reporting of RT details is a major limitation of the included studies. The severity of acute and late chronic effects of RT are partially related to the dose received by critical structures ,55. In pNo studies report on the clinical utilisation or implementation of HRQoL assessments into routine practice. This is despite the growing body of evidence and calls for the integration of HRQoL assessment using patient-reported outcome measures into routine care to improve clinical outcomes and patient satisfaction ,60,61,62Another key solution to drive change will be an international effort to increase quality data collection following both XRT and PRT, and to promote data sharing to aid comparisons. This is underway and shown by the collaborative studies included in this review. Pediatric Proton Photon Consortium Registry and PanCareLIFE, are key examples of international consortia collecting longitudinal HRQoL outcomes for children with cancer, during and following XRT and PRT, to accompany clinical data ,65. FurtA potential limitation of this review is the inclusion of studies by the same institutions, with potentially overlapping patient cohorts. However, studies were not included in the analysis if they were estimated to have ≥50% of the same participants. This review does not include conference abstracts or grey literature, which may have described clinical action based upon HRQoL assessments, or provided further insight into potential routine assessment. Additionally, some studies may have been excluded during the screening processes by inadvertent human error or bias. Studies utilising ‘life functioning’ assessments were excluded because physical functioning may not be directly associated with the psychosocial domains of HRQoL, and do not consider the personal perspective of physical functioning on the individual’s HRQoL . There iThere is a large gap in the literature describing the HRQoL of non-CNS childhood cancer survivors following RT, and, hence, non-CNS diagnoses are underrepresented in this review. In countries where XRT is the standard of care, future research is needed to evaluate the HRQoL outcomes of XRT patients, particularly with intensity-modulated RT and volumetric-modulated arc therapy, to accompany the growing PRT evidence.There is currently insufficient evidence to compare and determine if a difference exists between the HRQoL of children following XRT and PRT. There are limited rigorous HRQoL data following both XRT and PRT. This review highlights the importance of enhanced HRQoL collection, given the expanding global availability of PRT facilities, before concluding that PRT provides HRQoL improvements for this cohort. Standardised clinical implementation of HRQoL assessment using patient-reported outcomes may contribute to improvements in clinical care, and assist the rapid progression of knowledge comparing XRT and PRT. Improved reporting of prescribed dose and organ at risk dose constraints to accompany HRQoL assessments will assist in quantifying HRQoL outcomes for childhood cancer survivors following RT as treatment delivery techniques evolve.


Although traditional meat products are highly popular with consumers, the high levels of unsaturated fatty acids and cholesterol present significant health concerns. However, simply using plant oil rich in unsaturated fatty acids to replace animal fat in meat products causes a decline in product quality, such as lower levels of juiciness and hardness. Therefore, it is necessary to develop a fat substitute that can ensure the sensory quality of the product while reducing its fat content. Consequently, using emulsion gels to produce structured oils or introducing functional ingredients has attracted substantial attention for replacing the fat in meat products. This paper delineated emulsion gels into protein, polysaccharide, and protein–polysaccharide compound according to the matrix. The preparation methods and the application of the three emulsion gels as fat substitutes in meat products were reviewed. Since it displayed a unique separation structure, the double emulsion was highly suitable for encapsulating bioactive substances, such as functional oils, flavor components, and functional factors, while it also exhibited significant potential for developing low-fat or functional healthy meat products. This paper summarized the studies involving the utilization of double emulsion and gelled double emulsion as fat replacement agents to provide a theoretical basis for related research and new insight into the development of low-fat meat products. Fat-rich meat products are popular with consumers due to their sensory properties. Fat is closely related to several food characteristics, such as texture, taste, and appearance. It also acts as a structuring and tasting agent, supplies energy, serves as a carrier ,2,3, andFrankfurters, bologna sausage, beef patties, and other popular meat products typically contain 20–30% fat . The WHOAdding fat substitutes to meat products to improve the fatty acid proportions can benefit consumer health. Adding fat substitutes can reduce the fat content in meat products and enhance the distribution of fatty acids. Since the fatty acid composition and proportion significantly impact human health, the polyunsaturated fatty acid (PUFA) to SFA ratio should be between 0.4 and 1.0. Furthermore, because unsaturated fatty acids also have substantial health implications, it is recommended that the n-6/n-3 PUFA ratio not exceed 4. A high n-6/n-3 PUFA ratio can promote the incidence of cardiovascular disease, inflammation, and other disorders. Some meat, such as pork, presents suboptimal fatty acid ratios ,10.Using plant oil rich in unsaturated fatty acids to replace animal fat abundant in SFAs is currently attracting significant research attention. However, simply using plant oils to replace animal fats causes a decline in product quality, since animal fats display a solid, elastic structure at room temperature absent in liquid oils. The adipose tissue in meat products consists of liquid oil and solid fat in the connective tissue network, exhibiting both plastic and elastic properties. Animal fat particles play a critical role in the cooking loss rate, hardness, texture, juiciness, flavor, and appearance of meat products . TherefoRecent studies have focused on utilizing emulsion gels to substitute the animal fat in meat products, forming a network structure via carbohydrate or protein cross-linking, which acted as a matrix for structural fat simulation. Emulsion gel formation is considered a strategy for oil stabilization and structuring, presenting advantages such as transporting functional components and improving the sensory and physical product properties. Since emulsion gels are highly suitable for developing healthy meat products, many studies are currently examining their application prospects. Double emulsion displays potential for active substance encapsulation and can also be used to formulate fat substitutes. Although some studies have investigated the application of double emulsions and the utilization of double emulsion gel as a fat substitute in meat products, the research is still immature.An emulsion is a colloidal dispersion generated by a liquid in the form of small droplets distributed in another insoluble liquid . EmulsioEmulsion gels typically use a stable protein emulsion as a matrix, while the excellent emulsification characteristics of proteins allow them to be adsorbed on the oil–water interface to stabilize the oil droplets . In emulThe emulsion gel preparation process mainly consists of two steps: stable emulsion preparation and gel formation. After adding an emulsifier, water and oil are mixed via high-pressure homogenization or high-speed mixing  to form Obtaining a solid-like emulsion gel involves continuous phase gelation (emulsion-droplet-filled gels) or droplet aggregation (emulsion-droplet-aggregated gels). The second step involves inducing the stable emulsion to an emulsion gel , which iHeat treatment (>65 °C) is a simple, rapid method commonly used for converting protein-stabilized emulsions into gels. During the heat process, the folded structures of the protein molecules open due to denaturation and aggregation, allowing the unfolded protein to form new intra- and interchain disulfide bonds. In appropriate conditions, the gel networks aggregate to form three-dimensional (3D) structures via the interaction between chemical forces, such as disulfide bonds, hydrogen bonds, and the hydrophobic interaction between molecules . Extendi2+ from CaCl2, which changes the pH and ionic strength to reduce the electrostatic repulsion between the proteins. This process promotes ionic cross-linking, allowing protein aggregates to form gel networks, increasing the ionic strength, and accelerating protein aggregation to generate larger aggregates . G. G2 to fHowever, compared with dairy products, not many studies exist involving fat substitution with double emulsions in meat products. Therefore, many challenges remain regarding the utilization of double emulsions in meat systems. In current studies, the double emulsion is mostly directly added to meat batter as a fat substitute but is rarely gelatinized. This may be due to the process complexity and post-processing instability of the gelled double emulsion, slowing down the research progress and application of this strategy. The emulsification process, W/O ratio, and types of surfactants can all affect the stability of the gelled double emulsion. Therefore, further research is required regarding the development and production of double emulsions and gelled double emulsions for low-fat meat products.The results indicate that the emulsion gel can effectively reduce the fat content in meat products, improve the composition and proportion of fatty acids, and allow the products to be labeled as “reduced fat content”.(1)Emulsion gels are suitable as fat substitutesThe choice of raw material is crucial for the structures of emulsion gels used as fat substitutes. The oil selected for the lipid phase, the protein and polysaccharide matrix interactions, and different gelation conditions make it possible to design a more ideal emulsion gel structure, affecting the structural and sensory properties of the product after incorporation into meat products. The use of fat substitutes in meat products can render them more compliant with the nutritional health needs of consumers by improving the fat content and fatty acid composition. When preparing emulsion gels as fat substitutes, liquid oil rich in unsaturated fatty acids can be selected as O. Plant oil with high unsaturated content is prone to oxidative deterioration. The characteristics of emulsion gels allow them to embed bioactive antioxidant substances in structured oil and enhance the stability of highly unsaturated oil. Furthermore, structured liquid oil converted into an emulsion gel can exhibit rheological properties similar to animal fat. The stabilization and structuring of liquid oils is a promising processing method achieved via emulsion gel preparation. Therefore, an emulsion gel provides a way to incorporate healthier oils into meat products.(2)The development of solid cube fat mimeticsAdding specific emulsion gel proportions to meat products does not reduce the processing and sensory properties of the products or remains within the acceptable range for consumers. Completely replacing the fat using substitutes leads to a decline in the sensory properties. Although the emulsion gels prepared by some studies display gel structures, they exhibit high viscosity and a soft texture, making it difficult to obtain 3D cubes, while other research has shown that emulsion gels can simulate 3D fat cubes. In some meat products, such as sausages, well-separated cube fat particles are typically required to provide the desired mouth feel and visible fat cube appearance. However, the preparation of solid cube fat requires emulsion gels with a certain hardness and gel structure strength. This can be explored and developed in the future by changing the type and concentration of matrix raw materials and gel method.(3)The development of double emulsions and gelled double emulsions as fat replacers1 while avoiding the negative impact on sensory properties when added directly. Further research is required regarding the stability of double emulsions, especially the development of gelled double emulsions, which may lead to better sensory versus cooking properties of the fat substitutes in meat products.Double emulsions display unique separation structures that can be used to develop alternative fat while being capable of effective encapsulation to protect hydrophilic bioactive compounds, pigments, flavor substances, and enzymes. Although they are currently applied for researching fat substitutes in meat products, most are directly added to the model meat batter in the form of emulsions. The research on the application of gelled double emulsion is limited, while there is also a lack of studies on cube fat mimics, which may be related to poor stability. Double emulsions can be used to encapsulate the unpleasant flavors in fat substitutes or protect the active substances added to the W