Calderon, Gerardo

AbstractBackgroundFood intake is regulated by homeostatic and hedonic systems that interact in a complex neuro‐hormonal network. Dysregulation in energy intake can lead to obesity (OB) or anorexia nervosa (AN). However, little is known about the neurohormonal response patterns to food intake in normal weight (NW), OB, and AN.Material & MethodsDuring an ad libitum nutrient drink (Ensure®) test (NDT), participants underwent three pseudo‐continuous arterial spin labeling (pCASL) MRI scans. The first scan was performed before starting the NDT after a > 12 h overnight fast (Hunger), the second after reaching maximal fullness (Satiation), and the third 30‐min after satiation (postprandial fullness). We measured blood levels of ghrelin, cholecystokinin (CCK), glucagon‐like peptide (GLP‐1), and peptide YY (PYY) with every pCASL‐MRI scan. Semiquantitative cerebral blood flow (CBF) maps in mL/100 gr brain/min were calculated and normalized (nCBF) with the CBF in the frontoparietal white matter. The hypothalamus (HT), nucleus accumbens [NAc] and dorsal striatum [DS] were selected as regions of interest (ROIs).ResultsA total of 53 participants, 7 with AN, 17 with NW (body‐mass index [BMI] 18.5–24.9 kg/m2), and 29 with OB (BMI ≥30 kg/m2) completed the study. The NW group had a progressive decrease in all five ROIs during the three stages of food intake (hunger, satiation, and post‐prandial fullness). In contrast, participants with OB showed a minimal change from hunger to postprandial fullness in all five ROIs. The AN group had a sustained nCBF in the HT and DS, from hunger to satiation, with a subsequent decrease in nCBF from satiation to postprandial fullness. All three groups had similar hormonal response patterns with a decrease in ghrelin, an increase in GLP‐1 and PYY, and no change in CCK.ConclusionConditions of regulated (NW) and dysregulated (OB and AN) energy intake are associated with distinctive neurohormonal activity patterns in response to hunger, satiation, and postprandial fullness.

AbstractBackgroundNumerous individual and environmental factors including diet may play an important role in the pathophysiology of irritable bowel syndrome (IBS). It is unclear to what degree dietary intake is affected in individuals with IBS. We aimed to perform a systematic review and meta‐analysis to summarize dietary intake of adults with IBS and to compare dietary intake between adults with IBS and non‐IBS controls.MethodsOvid MEDLINE, Embase, Cochrane, CINAHL, and Scopus were searched through February 2023 for clinical trials and observational studies measuring usual diet in adults with IBS. Pooled weighted averages were estimated for total energy, macronutrient, and micronutrient data. Mean differences (MD) in nutrient intake were estimated for adults with IBS versus non‐IBS controls using a random effects model. Heterogeneity was assessed by the inconsistency index (I2).Key ResultsSixty‐three full‐text articles were included in the review of which 29 studies included both IBS and control subjects. Nutrients not meeting the recommended intake level for any dietary reference values in the IBS population were fiber and vitamin D. Meta‐regression by female proportion was positively correlated with total fat intake and negatively correlated with carbohydrate intake. Comparisons between participants with IBS and controls showed significantly lower fiber intake in participants with IBS with high heterogeneity (MD: −1.8; 95% CI: −3.0, −0.6; I2 = 85%).Conclusions and InferencesThis review suggests that fiber and vitamin D intake is suboptimal in IBS; however, overall dietary intake does not appear to be comprised. Causes and consequences of reduced fiber in IBS deserve further study.Results of this systematic review and meta‐analysis suggest that fiber and vitamin D intake is suboptimal in IBS. However, overall intake of other macro‐ and micronutrients does not appear to be compromised. Causes and consequences of reduced fiber and Vitamin D intake in IBS deserve further study.

We show how switching from a regular diet to an HCHF increases cholesterol absorption in patients with normal weight and obesity. The decrease in cholesterol absorption from an HCHF to an LCLF, on the other hand, was only seen in normal-weight controls, underlining the importance of body weight in this regulation. In addition, changes in caloric and fat content had an immediate and direct effect on hepatic bile acid production.

AbstractObjectiveSatiety, defined as the duration of the sensation of fullness, is usually measured by validated visual analog scales (VAS) for appetite. Gastric function plays a key role in food intake regulation. However, the association between gastric emptying (GE) and VAS appetite is unknown.MethodsIn this cross‐sectional study, 134 participants (mean [SEM] age = 39 [0.8] years, mean [SEM] BMI = 38 [0.5] kg/m2, 67% females) completed simultaneous measurements of GE and VAS appetite. After a 320‐kcal meal, GE was measured by scintigraphy and appetite by validated 100‐mm VAS for 240 minutes. Satiation was defined as calories consumed to terminate meal and was measured by an ad libitum meal. GE, VAS, and ad libitum meal tests were measured on the same day. Percent of meal retention in the stomach, VAS area under curve (AUC0‐240 min), and overall appetite score (OAS) were calculated. Pearson correlation (ρ) determined the association of GE with VAS appetite and satiation. Appetite components were also analyzed by quartiles based on GE120 min.ResultsGE120 min was correlated with sensation of VAS hungerAUC(0‐240 min) (ρ = 0.24, p = 0.004), fullnessAUC(0‐240 min) (ρ = 0.16, p = 0.05), and OASAUC(0‐240 min) (ρ = 0.20, p = 0.02). Patients with rapid GE120 min had a mean increase in VAS hungerAUC(0‐240 min) by 32 mm/min (15.62%, p = 0.03) compared with normal/slow GE120 min.ConclusionsGE is associated with the sensations of appetite, and rapid GE is associated with increased appetite, which may contribute to weight gain.

ObjectiveLittle is known about the predictors of response to obesity interventions.MethodsIn 450 participants with obesity, body composition, resting energy expenditure, satiety, satiation, eating behavior, affect, and physical activity were measured by validated studies and questionnaires. These variables were used to classify obesity phenotypes. Subsequently, in a 12‐month, pragmatic, real‐world trial performed in a weight management center, 312 patients were randomly assigned to phenotype‐guided treatment or non‐phenotype‐guided treatment with antiobesity medications: phentermine, phentermine/topiramate, bupropion/naltrexone, lorcaserin, and liraglutide. The primary outcome was weight loss at 12 months.ResultsFour phenotypes of obesity were identified in 383 of 450 participants (85%): hungry brain (abnormal satiation), emotional hunger (hedonic eating), hungry gut (abnormal satiety), and slow burn (decreased metabolic rate). In 15% of participants, no phenotype was identified. Two or more phenotypes were identified in 27% of patients. In the pragmatic clinical trial, the phenotype‐guided approach was associated with 1.75‐fold greater weight loss after 12 months with mean weight loss of 15.9% compared with 9.0% in the non‐phenotype‐guided group (difference −6.9% [95% CI −9.4% to −4.5%], P < 0.001), and the proportion of patients who lost >10% at 12 months was 79% in the phenotype‐guided group compared with 34% with non‐phenotype‐guided treatment group.ConclusionsBiological and behavioral phenotypes elucidate human obesity heterogeneity and can be targeted pharmacologically to enhance weight loss.

Background & Goals: Diet may contribute to symptoms of irritable bowel syndrome (IBS) and luminal production of putative IBS biomarkers including short-chain fatty acids (SCFAs). Study aims were to to assess relationships of habitual fiber or starch intake with fecal SCFAs in patients with IBS and healthy volunteers (HVs). Study: In 18 HVs and 30 patients with IBS (13 constipation-predominant [IBS-C] and 17 diarrhea-predominant [IBS-D]), habitual diet using a food frequency questionnaire; bowel functions using a validated bowel diary; and fecal SCFAs by HPLC-mass spectrometry were assessed. Associations of fiber and starch with SCFAs were analyzed using Spearman (r s ) and Pearson (R) correlations. Relationships between other dietary endpoints, SCFAs, and bowel functions were explored. Results: Habitual fiber or starch intakes were not significantly correlated with SCFAs or bowel functions in all participants or HVs nor with SCFAs in IBS. Starch was negatively correlated (R=−0.53; P=0.04) with complete evacuation in IBS-D. Fiber (r s =0.65; P=0.02) and starch (r s =0.56; P=0.05) were correlated with ease of passage in IBS-C. Stool form, frequency, and ease of passage were positively correlated with total SCFAs (all P<0.05), acetate (all P<0.01), propionate (all P<0.05), and butyrate (form P=0.01; ease of passage P=0.05) among all participants, but not in IBS. Complete evacuation was negatively correlated with propionate (R=−0.34; P=0.04) in all participants. Total (P=0.04) and individual SCFAs (all P<0.05) were positively correlated with stool form in HVs. Conclusions: Habitual fiber and starch intake does not influence fecal SCFAs but may influence bowel functions in IBS. Fecal SCFAs correlate with bowel functions among all participants including HVs.