Key messages
• It is unclear if precision nutrition (diets or foods tailored to people based on characteristics related to individual biology and environment) has an effect on weight change measured as body weight or body mass index (BMI) (a percentile measure of someone's weight relative to the average for a given age) in children and adolescents with obesity.
• Further research, including large studies, is needed to understand the effects of precision nutrition-based interventions on managing obesity in children and adolescents.
What is overweight and obesity?
Body mass index (BMI) is calculated by dividing a person's weight in kilograms by their height in metres, squared. BMI may be used to define overweight, a condition of excessive fat deposits, and obesity, a chronic disease characterised by excessive fat deposits that can impair health.
How is overweight and obesity managed?
Whilst obesity may be managed through changes in diet, lifestyle, surgery, or medications, approximately 37 million children under the age of five live with obesity as of 2022, and the prevalence (number of people with a condition in a population at a specific time) of obesity amongst adolescents has quadrupled since 1990. This suggests that alternative or complementary approaches to treatment may be required, such as personalised or precision nutrition-based interventions.
What did we want to find out?
Recently, 'precision nutrition' – the study of how an individual's behaviour, physiology, lifestyle, and diet can be used to design interventions – has grown in popularity as a potentially exciting and valuable tool against overweight and obesity. Early research into behavioural patterns and nutritional status suggests that these precision nutrition interventions may be useful in reducing the prevalence of overweight and obesity, particularly in children and adolescents.
We wanted to find out if precision nutrition-based interventions in children 0 to 9 years, adolescents 10 to 19 years, and both combined in a 0-to-19-year age group, were better than one-size-fits-all interventions to improve:
• physical and mental well-being;
• physical activity;
• health-related quality of life;
• obesity-associated disability;
• unwanted effects of the interventions;
• changes in weight as measured by BMI or body weight.
What did we do?
We searched for studies that looked at precision nutrition-based interventions (involving dietary advice or education with either artificial intelligence or 'omics-based' methods (scientific tools that quantify and study groups of biological molecules relevant to the function of the human body and its cells)) compared with one-size-fits-all interventions (e.g. general calorie reduction or dietary pattern without accounting for individual characteristics) or no intervention in children and adolescents up to 19 years of age. We compared and summarised the results of the studies and rated our confidence in the evidence based on factors such as study methods and sizes.
What did we find?
We found 2 trials that involved 105 children and adolescents with overweight or obesity, which lasted 1 to 3 months.
Amongst children (0 to 9 years of age), it is unclear if a precision nutrition-based diet has an effect on BMI or weight compared with a one-size-fits-all intervention.
Similarly, in children and adolescents (10 to 19 years of age), it is unclear if a precision nutrition-based diet has an effect on BMI or weight compared with a one-size-fits-all intervention.
What are the limitations of the evidence?
The main limitations of the evidence were the small numbers of people and lack of studies overall. We therefore have little confidence in the evidence because there were not enough studies to be certain about the results, and the included studies were very small; also, the evidence does not cover all the people we were interested in. Further research, including large studies, is needed to better understand how precision nutrition interventions may be used in the treatment or management of overweight and obesity in children and adolescents.
How up-to-date is this evidence?
This evidence is current to July 2024.
Based on data from two small studies with a total of 105 participants, the evidence is very uncertain about the effect of precision nutrition-based interventions on body weight or BMI. This review was limited by the number of available randomised controlled trials in this relatively nascent field. Given these limitations, the two studies do not provide sufficient evidence to adequately inform practice. Future research should report participant outcome data, including outcomes related to mental, emotional, and functional well-being, in addition to biochemical and physical measures, stratified by World Health Organization-defined age groups (children (0 to 9 years), and children and adolescents (10 to 19 years)). Future studies should also report methods related to randomisation, blinding, and compliance, as well as include prespecified analysis plans.
Precision nutrition-based methods develop tailored interventions and/or recommendations accounting for determinants of intra- and inter-individual variation in response to the same diet, compared to current 'one-size-fits-all' population-level approaches. Determinants may include genetics, current dietary habits and eating patterns, circadian rhythms, health status, gut microbiome, socioeconomic and psychosocial characteristics, and physical activity. In this systematic review, we examined the evidence base for the effect of interventions based on precision nutrition approaches on overweight and obesity in children and adolescents to help inform future research and global guidelines.
To examine the impact of precision nutrition-based interventions for the management of obesity in children and adolescents in all their diversity.
We searched CENTRAL, MEDLINE, CINAHL, Web of Science Core Collection, BIOSIS Previews, Global Index Medicus (all regions), IBECS, SciELO, PAHO, PAHO IRIS, WHO IRIS, WHOLIS, Bibliomap, and TRoPHI, as well as the WHO ICTRP and ClinicalTrials.gov. We last searched the databases on 23 July 2024. We did not apply any language restrictions.
We included randomised or quasi-randomised controlled trials that evaluated precision nutrition-based interventions (accounting for 'omics' such as phenotyping, genotyping, gut microbiome; clinical data, baseline dietary intake, postprandial glucose response, etc., and/or including artificial intelligence such as machine learning methods) compared to general or one-size-fits-all interventions or no intervention in children and adolescents aged 0 to 9 years or 10 to 19 years with overweight or obesity.
Two review authors independently conducted study screening, data extraction, and risk of bias and GRADE assessments. We used fixed-effect analyses. Our outcomes of interest were physical and mental well-being, physical activity, health-related quality of life, obesity-associated disability, and adverse events associated with the interventions as defined or measured by trialists, and weight change (reduction, stabilisation or maintenance).
Two studies (3 references, 105 participants) conducted in Ukraine and Greece met our eligibility criteria. One study reported nonprofit funding sources, whilst the other did not report funding, and the certainty of evidence ranged from very low to low across outcomes (all measured at endpoint). Only one trial (65 participants) contributed data on our primary outcomes of interest.
Precision nutrition-based intervention versus one-size-fits-all intervention or standard of care
In children 0 to 9 years of age, evidence is very uncertain about the effect of a precision nutrition-based intervention (a computerised Decision Support Tool (DST) that incorporates a variety of participant data and provides personalised diet recommendations based on decision-tree algorithms) on body mass index (BMI) (mean difference (MD) −1.40 kg/m2, 95% confidence interval (CI) −3.48 to 0.68; 1 study, 35 participants; very low‐certainty evidence) and on weight (MD −2.60 kg, 95% CI −8.42 to 3.22; 1 study, 35 participants; very low‐certainty evidence) compared with a one-size-fits-all control intervention.
In children and adolescents 10 to 19 years of age, evidence is very uncertain about the effect of a precision nutrition-based intervention (computerised DST) on BMI (MD 3.00 kg/m2, 95% CI −0.26 to 6.26; 1 study, 30 participants; very low‐certainty evidence) and on weight (MD 11.40 kg, 95% CI −0.47 to 23.27; 1 study, 30 participants; very low‐certainty evidence) compared with a one-size-fits-all control intervention.