Postprandial suppression of appetite is more reproducible at a group than an individual level: Implications for assessing inter-individual variability

A systematic review of the use of the Satiety Quotient

The satiating efficiency of food has been increasingly quantified using the Satiety Quotient (SQ). The SQ integrates both the energy content of food ingested during a meal and the associated change in appetite sensations. This systematic review examines the available evidence regarding its methodological use and clinical utility. A literature search was conducted in six databases considering studies from 1900 to April 2020 that used SQ in adults, adolescents and children. All study designs were included. From the initial 495 references found, fifty-two were included. Of the studies included, thirty-three were acute studies (twenty-nine in adults and four in adolescents) and nineteen were longitudinal studies in adults. A high methodological heterogeneity in the application of the SQ was observed between studies. Five main utilisations of the SQ were identified: its association with (i) energy intake; (ii) anthropometric variables; (iii) energy expenditure/physical activity; (iv) sleep quality and quantity and (v) to classify individuals by their satiety responsiveness (i.e. low and high satiety phenotypes). Altogether, the studies suggest the SQ as an interesting clinical tool regarding the satiety responsiveness to a meal and its changes in responses to weight loss in adults. The SQ might be a reliable clinical indicator in adults when it comes to both obesity prevention and treatment. There is a need for more standardised use of the SQ in addition to further studies to investigate its validity in different contexts and populations, especially among children and adolescents.

True Interindividual Variability Exists in Postprandial Appetite Responses in Healthy Men But Is Not Moderated by the FTO Genotype

BACKGROUND

After meal ingestion, a series of coordinated hormone responses occur concomitantly with changes in perceived appetite. It is not known whether interindividual variability in appetite exists in response to a meal.

OBJECTIVES

The aim of this study was to 1) assess the reproducibility of appetite responses to a meal; 2) quantify individual differences in responses; and 3) explore any moderating influence of the fat mass and obesity associated (FTO) gene.

METHODS

Using a replicated crossover design, 18 healthy men (mean ± SD age: 28.5 ± 9.8 y; BMI: 27.0 ± 5.0 kg/m2) recruited according to FTO genotype (9 AA, 9 TT) completed 2 identical control and 2 identical standardized meal conditions (5025 kJ) in randomized sequences. Perceived appetite and plasma acylated ghrelin, total peptide YY (PYY), insulin, and glucose concentrations were measured before and after interventions as primary outcomes. Interindividual differences were explored using Pearson's product-moment correlations between the first and second replicates of the control-adjusted meal response. Within-participant covariate-adjusted linear mixed models were used to quantify participant-by-condition and genotype-by-condition interactions.

RESULTS

The meal suppressed acylated ghrelin and appetite perceptions [standardized effect size (ES): 0.18-4.26] and elevated total PYY, insulin, and glucose (ES: 1.96-21.60). For all variables, SD of change scores was greater in the meal than in the control conditions. Moderate-to-large positive correlations were observed between the 2 replicates of control-adjusted meal responses for all variables (r = 0.44-0.86, P ≤ 0.070). Participant-by-condition interactions were present for all variables (P ≤ 0.056). FTO genotype-by-condition interactions were nonsignificant (P ≥ 0.19) and treatment effect differences between genotype groups were small (ES ≤ 0.27) for all appetite parameters.

CONCLUSIONS

Reproducibility of postprandial appetite responses is generally good. True interindividual variability is present beyond any random within-subject variation in healthy men but we detected no moderation by the FTO genotype. These findings highlight the importance of exploring individual differences in appetite for the prevention and treatment of obesity. This trial was registered at clinicaltrials.gov as NCT03771690.