Impact of dietary and obesity genetic risk scores on weight gain

Role of Planetary Health Diet in the association between genetic susceptibility to obesity and anthropometric measures in adults

BACKGROUND/OBJECTIVE

The roles of overall diet quality in linking genetic background with anthropometric measures are unclear, particularly regarding the recently developed Planetary Health Diet (PHD). This study aims to determine if the PHD mediates or moderates the relationship between genetic susceptibility to obesity and anthropometric measures.

SUBJECTS/METHODS

The study involved 2942 individuals from a Finnish population-based cohort (54% women, mean age 53 (SD ± 13) years). Habitual diet was assessed using a validated 130-item food frequency questionnaire, and the PHD Score (total score range 0-13 points) was adapted for Finnish food culture to evaluate diet quality. Genetic susceptibility to obesity was evaluated with a polygenic risk score (PRS) based on one million single nucleotide polymorphisms associated with body mass index (BMI). Baseline anthropometrics included weight, height, waist circumference (WC), and body fat percentage, with changes in these measures tracked over 7 years. A five-step multiple linear regression model and multivariable logistic regression with interaction terms were used to assess the mediating and moderating effects of the PHD. These analyses were also replicated in another Finnish cohort study (2 834 participants).

RESULTS

PRS for BMI was positively associated with baseline BMI and changes in anthropometric measures, except waist circumference (p = 0.12). Significant associations were observed for baseline BMI and WC (p < 0.001), changes in BMI and WC (p = 0.01), and body fat percentage change (p = 0.05). However, the PHD (average score 3.8 points) did not mediate or moderate these relationships. These findings were consistent in the replication cohort.

CONCLUSION

Diet quality assessed with the PHD did not mediate or moderate the associations between genetic susceptibility to obesity and anthropometric measures. This lack of effect may be partly due to low adherence to the PHD and the older age of participants ( > 50 years) at baseline.

Interactions between polygenic risk of obesity and dietary factors on anthropometric outcomes: A systematic review and meta-analysis of observational studies

BACKGROUND

Diet is an important determinant of health and may moderate genetic susceptibility to obesity, but meta-analyses of available evidence are lacking.

OBJECTIVES

This study aimed to systematically review and meta-analyze evidence on the moderating effect of diet on genetic susceptibility to obesity, assessed with polygenic risk scores (PRS).

METHODS

A systematic search was conducted using MEDLINE, EMBASE, Web of Science, and the Cochrane library to retrieve observational studies that examined PRS-diet interactions on obesity-related outcomes. Dietary exposures of interest included diet quality/dietary patterns and consumption of specific food and beverage groups. Random effects meta-analyses were performed for pooled PRS-Healthy Eating Index (HEI) interaction coefficients on body mass index (BMI) (based on data from four cohort studies) and waist circumference (based on data from three cohort studies).

RESULTS

Out of 36 retrieved studies, 78% were conducted among European samples. Twelve out of 21 articles examining dietary indices/patterns, and 16 out of 21 articles examining food/beverage groups observed some significant PRS-diet interactions. However, within many articles, findings are inconsistent when testing different combinations of obesity PRS-dietary factors and outcomes. Nevertheless, higher HEI scores and adherence to plant-based dietary patterns emerged as the more prominent diet quality/patterns that moderated genetic susceptibility to obesity, while higher consumption of fruits and vegetables, and lower consumption of fried foods and sugar-sweetened beverages emerged as individual food/beverage moderators. Results from the meta-analysis suggest that a higher HEI attenuates genetic susceptibility on BMI (pooled PRS*HEI coefficient: -0.08; 95% confidence interval (CI): -0.15, 0.00; p=0.0392) and waist circumference (-0.37; 95% CI: -0.60, -0.15; p=0.0013).

CONCLUSIONS

Current observational evidence suggests a moderating role of overall diet quality in polygenic risk of obesity. Future research should aim to identify genetic loci that interact with dietary exposures on anthropometric outcomes and conduct analyses among diverse ethnic groups.

PROSPERO

CRD42022312289.

Trade liberalization and nutrition transition: Evidence from China

We examine the impact of trade liberalization on the nutrition transition between 1997 and 2011. Our findings demonstrate that the reduction in tariff rates has had a significant effect on the dietary patterns of both rural and urban residents in the country. With the decrease in tariffs, there has been a noticeable increase in the consumption of animal products (such as meat and aquatic products), vegetables, beans and nuts, as well as packaged and processed foods. Simultaneously, there has been a decrease in the demand for staple foods, fruits, and dairy products. Consequently, there has been an increase in the proportion of overall calories derived from fat and protein, while the proportion from staple foods has declined. As a result, trade liberalization has led to increased food expenditure, while reducing the cost of maintaining a healthy diet. Furthermore, trade liberalization has also contributed to a growing risk of obesity. Additionally, our study identifies rising incomes, specialization in agricultural production, changing food prices, and shifting food preferences as the primary mechanisms of the trade-diet relationship.

Vitamin D and Weight Change: A Mendelian Randomization, Prospective Study

The association between 25-hydroxyvitamin D and 5-, 10-, or 15-year weight change were assessed in a population-based, prospective study conducted in Lausanne, Switzerland. Data from the first (2009−2012, N = 3527, 51.3% women), second (2014−2017, N = 3237, 53.8% women), and third (2018−2021, N = 2567, 54.2% women) follow-ups were used. A weighted genetic risk score (GRS) of 115 SNPs associated with vitamin D levels was constructed. At baseline, the GRS correlated positively with 25-hydroxyvitamin D levels based on a Spearman rank correlation and 95% confidence interval: 0.198 (0.166; 0.231), p < 0.001; and with body mass index: 0.036 (0.004; 0.068), p = 0.028. No association was found between quartiles of GRS and weight changes at 5, 10, or 15 years: multivariate-adjusted weight changes ± SEM at 5-years follow-up were 1.39 ± 0.17, 1.13 ± 0.17, 1.24 ± 0.17, and 1.00 ± 0.17 kg for the first to the fourth quartile of the GRS, respectively (p = 0.401). Two-step linear regression showed a significant but clinically meaningless association between GRS-derived vitamin D and weight change at 5- and 15-years: slope and 95% confidence interval for a 5 nmol/L increase in GRS-derived 25-hydroxyvitamin D levels: 0.082 (0.013; 0.150) and 0.130 (0.018; 0.243) kg, respectively. We conclude that there is little association between genetically determined 25-hydroxyvitamin D levels and weight gain.

The interaction between Alternative Healthy Eating Index and MC4R rs17782313 gene variants on central and general obesity indices in women: a cross-sectional study

BACKGROUND

Previous studies have shown that the C allele of melanocortin 4 receptor (MC4R) rs17782313 and Alternative Healthy Eating Index (AHEI) are separately associated with obesity. However, no study has assessed the aim of this study which is to investigate the interaction between MC4R rs17782313 variants and AHEI and their association with central and general obesity indices.

METHODS

A total of 291 women with BMI ≥25 and aged 18-48 years enrolled in this cross-sectional study. All participants were assessed for body composition, anthropometric measures, dietary intake, and blood parameters. After obtaining data of dietary intake from the 147-item food frequency questionnaire (FFQ) the AHEI was calculated. MC4R rs17782313 SNPs were assessed using the restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

After adjustment for age, energy intake, physical activity, marital and economic status, the interaction between MC4R rs17782313 and AHEI was associated with hip circumference (HC) (β=-0.41, 95%CI: -0.77 to -0.05, P=0.02), body mass index (BMI) (β=-0.15, 95%CI: -0.29 to -0.02, P=0.02), fat mass (kg) (β=-0.28, 95%CI: -0.56 to -0.01, P=0.03), Visceral fat area (VFA) (β=-5.68, 95%CI: -9.55 to -1.80, P=0.004). The other measures that seem to be suggestively related to this interaction (0.05< P <0.07) are waist circumference (WC), waist-to-height ratio (WHtR), trunk fat (TF) (%), TF (kg), fat mass (%), and fat mass index (FMI).

CONCLUSION

Interaction between MC4R rs17782313 and AHEI can be related to some central and general obesity indices in overweight/obese women. This article is protected by copyright. All rights reserved.

Dietary patterns, genetic risk, and incidence of obesity: Application of reduced rank regression in 11,735 adults from the UK Biobank study

Few studies have derived dietary patterns based on intake of discretionary foods and beverages and examined associations with genetic risk and obesity. We examined associations between dietary patterns based on discretionary foods, saturated fatty acids (SFA), and fiber, with a polygenetic risk score (PRS) for obesity and risk of overall obesity, central obesity and high body fat (BF) up to 9.7 years later. Data from 11,735 adults from the UK Biobank cohort study were used. Dietary patterns were derived from 24-h dietary assessments using reduced rank regression (response variables: discretionary foods and beverages [%E]; SFA [%E]; fiber density [g/MJ]). Cox proportional hazard models were used to investigate associations between dietary patterns and incident overall obesity, central obesity and high BF, with interactions by PRS. Three dietary patterns (DP) were identified. DP1, correlated positively with discretionary foods and SFA, inversely with fiber, was associated with higher risk of central obesity (hazard ratio: 1.08; 95% confidence interval: 1.02, 1.14). DP2, correlated positively with discretionary foods and fiber, inversely with SFA, was not associated with obesity incidence. DP3, correlated positively with SFA and fiber, inversely with discretionary foods, was associated with lower risk of central obesity (hazard ratio: 0.92; 95% confidence interval: 0.87, 0.98). There was limited evidence of interactions with PRS. A dietary pattern high in high-SFA and low-fiber discretionary foods and beverages was associated with higher risk of obesity, independent of genetic predisposition.

Mediterranean Diet and Genetic Determinants of Obesity and Metabolic Syndrome in European Children and Adolescents

Childhood obesity and metabolic syndrome (MetS) are multifactorial diseases influenced by genetic and environmental factors. The Mediterranean Diet (MD) seems to modulate the genetic predisposition to obesity or MetS in European adults. The FTO gene has also been shown to have an impact on the MD benefits to avoid obesity or MetS. Since these interaction effects have been scarcely analyzed in European youth, the aim was to describe the gene–MD interplay, analyzing the impact of the genetic factors to reduce the obesity and MetS risk through MD adherence, and the MD impact in the obesity and MetS genetic profile. From the limited evidence on gene–MD interaction studies in European youth, a study showed that the influence of high MD adherence on adiposity and MetS was only observed with a limited number of risk alleles; the gene–MD interplay showed sex-specific differences, being higher in females. Most results analyzed in European adults elucidate that, the relationship between MD adherence and both obesity and MetS risk, could be modulated by obesity genetic variants and vice versa. Further research is needed, to better understand the inter-individual differences in the association between MD and body composition, and the integration of omics and personalized nutrition considering MD.