Diet-induced Weight Loss and Phenotypic Flexibility Among Healthy Overweight Adults: A Randomized Trial

Multi-study feasibility analysis on a composite biomarker of inflammatory resilience to quantify the effects of energy restriction on low-grade inflammation in overweight and obese individuals

PURPOSE

Assessing the health impacts of nutritional interventions in metabolically compromised but otherwise healthy individuals is challenging, necessitating sensitive tools. Phenotypic flexibility offers an innovative way to measure homeostatic capacity during challenge tests. A composite biomarker of inflammatory resilience has proven useful in evaluating the health benefits of whole-grain wheat interventions in overweight and obese individuals. Expanding this method to other dietary interventions to combat low-grade inflammation is essential.

METHODS

This study investigated the feasibility of a composite biomarker of inflammatory resilience through secondary analysis of samples from two independent energy restriction (ER) trials, Bellyfat (NCT02194504) and Nutritech (NCT01684917). In these trials, fasting and postprandial inflammation was analysed using a variety of markers. Four composite biomarker models were developed on the basis of postprandial inflammatory marker responses via the 'health space' model method. These models were statistically evaluated for their sensitivity in detecting the effects of 12 weeks of ER.

RESULTS

The minimal composite biomarkers, consisting of IL-6, IL-8, IL-10, and TNF-α, lacked the ability to detect postprandial intervention effects in both ER trials. However, in the Nutritech study, the extended, endothelial, and optimized composite biomarkers of inflammatory resilience displayed significant responses to the ER (all P < 0.005). In the latter 3 models, a reduction in the inflammatory score was correlated with a reduction in BMI and body fat percentage.

CONCLUSION

This study underscores the feasibility of employing a composite biomarker of inflammatory resilience to evaluate ER interventions. Further validation in additional nutritional intervention studies is necessary. Once validated, this composite biomarker could offer a novel approach for assessing low-grade inflammation and phenotypic flexibility.

Quantifying the effect of nutritional interventions on metabolic resilience using personalized computational models

The manifestation of metabolic deteriorations that accompany overweight and obesity can differ greatly between individuals, giving rise to a highly heterogeneous population. This inter-individual variation can impede both the provision and assessment of nutritional interventions as multiple aspects of metabolic health should be considered at once. Here, we apply the Mixed Meal Model, a physiology-based computational model, to characterize an individual's metabolic health in silico. A population of 342 personalized models were generated using data for individuals with overweight and obesity from three independent intervention studies, demonstrating a strong relationship between the model-derived metric of insulin resistance (ρ = 0.67, p < 0.05) and the gold-standard hyperinsulinemic-euglycemic clamp. The model is also shown to quantify liver fat accumulation and β-cell functionality. Moreover, we show that personalized Mixed Meal Models can be used to evaluate the impact of a dietary intervention on multiple aspects of metabolic health at the individual level.

Large metabolic swings: when feeding exceeds its goals

Exaggerated blood excursions of nutrients and endogenous molecules in response to food intake may have health consequences if they repeatedly exceed the capacity of homeostatic mechanisms. Here, I discuss the significance of abnormally high postprandial metabolic fluctuations, the role of some influencing factors, and suggest ways to avoid them.