Tilde Martinsen, Lorraine Brennan
Journal: Food & function 2026
PMID: 41493072
Standard dietary guidelines are designed for the general population, but individuals respond differently to the same foods. Personalised nutrition aims to tailor dietary advice based on personal characteristics such as current eating habits, body measurements, metabolic markers (like blood sugar or cholesterol), genetic information, or gut microbiome profiles. Because interest in personalised nutrition is growing, it is important to evaluate whether it truly offers benefits beyond standard healthy eating advice.This review of randomised controlled trials (RCTs) aimed to assess existing research on personalised nutrition approaches and determine whether they improve dietary behaviours or health outcomes. A total of 24 RCTs were included.
The review found that personalised nutrition interventions generally led to modest improvements in dietary behaviour compared to standard advice. Some studies also reported improvements in metabolic health markers such as blood sugar, cholesterol, or body weight. However, results were not consistent across all studies. The degree of benefit appeared to depend on how personalised the intervention was and which biological markers were used. The authors also identified limitations in the current evidence, including small sample sizes, short study durations, and variability in study design.
In conclusion, personalised nutrition shows promise for improving dietary behaviours and some health outcomes, but the evidence is still evolving. More large, well-designed trials are needed to determine which personalisation strategies are most effective and cost-efficient. Healthcare professionals may use these findings to understand that tailored dietary advice can enhance patient engagement and potentially improve outcomes, but recommendations should still be grounded in established evidence-based dietary principles.
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• Personalised nutrition can improve health even without weight loss.
• Health improvements as a result of personalised nutrition may include improved blood sugar and metabolic health.
• Individuals respond differently to diets depending on metabolism, diet, and biology.
Introduction –
Nutritional guidelines that emphasise the need for a varied and balanced diet are a key strategy for prevention and management of non-communicable diseases, such as obesity, type 2 diabetes and cardiovascular disease. Despite this, many individuals fail to meet dietary recommendations, particularly regarding fruit and vegetable intake. This gap between guidance and dietary behaviour highlights a need for a more effective strategy to improve health outcomes.
Personalised nutrition may address this gap by helping to tailor dietary recommendations to individuals based upon their genetic characteristics, needs, lifestyle, and metabolic profile.
This review aimed to synthesise the literature on the efficacy of various personalised nutrition approaches.
Methods –
A search was performed on PubMed using the Population, Intervention, Comparison, Outcome Study (PICOS) framework.
24 articles in adults were identified and put into one of three groups :
Group 1 delivered personalised nutrition recommendations based on dietary intake, phenotype data, and metabolic markers. 12 studies.
Group 2 delivered genotype-based personalised nutrition. 5 studies.
Group 3 used gut microbiome and machine learning algorithms to deliver dietary advice. 7 studies
Results –
The study identified that personalised nutrition improved dietary quality leading to improvements in metabolic markers, including HbA1c, triglycerides, and insulin sensitivity. Weight loss and blood pressure remained largely unaffected by personalised nutrition recommendations.
Genotype-based recommendations had a limited effect on clinical and behavioural outcomes such as weight loss, dietary intake, or metabolic markers.
Conclusion –
Personalised nutrition led to better compliance to healthy eating and improvements in some biomarkers in the short term. However, the impact of personalised nutrition was inconsistent in terms of clinical outcomes such as weight loss.
• Personalised nutrition recommendations may improve dietary-related behaviours when compared to standard dietary advice.
• Personalised nutrition may improve metabolic markers such as HbA1c, triglycerides, and insulin sensitivity.
• Clinicians should not solely rely upon genetic and microbiome data to direct dietary recommendations.
• Reductions in weight or blood pressure may be multifactorial and require further dietary and lifestyle analysis.
Future research could focus on determining which is the best dietary personalisation approach by identifying different dietary strategies and comparing outcomes.
Dietary changes can take time to affect health outcomes. Long term studies are required to assess efficacy and patient adherence. These studies should also include cost effectiveness comparisons for different approaches.
The field of personalised nutrition is growing and is based on the concept that delivering personalised dietary advice will be more effective than generic healthy eating guidelines for individuals to improve their diet and metabolic health. While there is substantial interest in the field, there is also a need to examine the evidence base. The objective of this review was to examine existing literature on the efficacy of personalised nutrition approaches and to identify research gaps and future needs. A literature search was conducted in PubMed for randomised controlled trials published between 2000 and 2025. Studies investigating the effects of personalised nutrition were included, and relevant papers were identified through the reference lists of existing papers. In total, 24 papers were included, with 12 studies investigating personalised nutrition based on current diet, phenotype, and metabolic biomarkers, five studies examining the effects of genotype-based personalised nutrition, and seven studies exploring approaches based on gut microbiome and machine learning algorithms. Overall, evidence from the included studies indicates that personalised nutrition approaches consistently improved dietary quality and led to significant improvements in metabolic markers, including HbA1c, triglycerides, and insulin sensitivity. However, few studies showed significant between-group differences in weight loss, and most studies did not find significant differences in blood pressure. While the results are promising, there are key challenges and research gaps that remain. Some approaches demonstrated potential for targeted improvements, but further high-quality research is needed to confirm their effectiveness and long-term impact. Future research should prioritise longer-term studies, better stratification of responders and non-responders, and cost-effectiveness evaluations to determine where and for whom personalised nutrition adds the most value.
© Copyright 2026, Nutrition Evidence
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