Overeating makes the gut grow fonder; new insights in gastrointestinal satiety signaling in obesity

Association of dietary total antioxidant capacity to anthropometry in healthy women: A cross-sectional study

OBJECTIVES

Reactive oxygen species level is a fundamental component in the pathogenesis of obesity that might be reduced by dietary antioxidants. Measurement of dietary total antioxidant capacity (DTAC) is regarded as a new holistic dietary index. Given the limited research on DTAC, the aim of this study was to examine the association of DTAC with obesity-related features in women.

METHODS

The present cross-sectional study included 627 female participants. Data on dietary intake were assessed using a validated food frequency questionnaire. DTAC was estimated through total reactive antioxidant potential (TRAP), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing ability of plasma (FRAP). Anthropometric parameters (body mass index and waist circumference), were investigated using standard methods.

RESULTS

After adjustment for possible covariates, both TRAP and TEAC were significantly positively associated with obesity (TRAP: OR, 1.65; 95% confidence interval [CI], 1.04-2.63; P_trend, 0.03; TEAC: OR, 1.63; 95% CI, 1.01-2.63; P_trend, 0.04). However, there was no association between FRAP and obesity (OR_, 1.11; 95% CI, 0.64-1.93; P_trend, 0.68). Moreover, no relationship was found between different DTAC indices and waist circumference (TRAP: OR, 1.13; 95% CI, 0.70-1.80; P_trend, 0.60; TEAC: OR, 1.04; 95% CI, 0.64-1.69; P_trend, 0.87; FRAP: OR, 0.86; 95% CI, 0.49-1.51; P_trend, 0.62).

CONCLUSION

Women with higher DTAC scores had higher risk for obesity. No association was found between DTAC and waist circumference.

Gastrointestinal Nutrient Infusion Site and Eating Behavior: Evidence for A Proximal to Distal Gradient within the Small Intestine?

The rapidly increasing prevalence of overweight and obesity demands new strategies focusing on prevention and treatment of this significant health care problem. In the search for new and effective therapeutic modalities for overweight subjects, the gastrointestinal (GI) tract is increasingly considered as an attractive target for medical and food-based strategies. The entry of nutrients into the small intestine activates so-called intestinal "brakes", negative feedback mechanisms that influence not only functions of more proximal parts of the GI tract but also satiety and food intake. Recent evidence suggests that all three macronutrients (protein, fat, and carbohydrates) are able to activate the intestinal brake, although to a different extent and by different mechanisms of action. This review provides a detailed overview of the current evidence for intestinal brake activation of the three macronutrients and their effects on GI function, satiety, and food intake. In addition, these effects appear to depend on region and length of infusion in the small intestine. A recommendation for a therapeutic approach is provided, based on the observed differences between intestinal brake activation.

Feeding-induced oleoylethanolamide mobilization is disrupted in the gut of diet-induced obese rodents

The gastrointestinal tract plays a critical role in the regulation of energy homeostasis by initiating neural and hormonal responses to the ingestion of nutrients. In addition to peptide hormones, such as cholecystokinin (CKK) and peptide YY (PYY), the lipid-derived mediator oleoylethanolamide (OEA) has been implicated in the control of satiety. Previous studies in humans and rodent models have shown that obesity is associated with changes in CCK, PYY and other gut-derived peptide hormones, which may contribute to decreased satiety and increased energy intake. In the present study, we show that small-intestinal OEA production is disrupted in the gut of diet-induced obese (DIO) rats and mice. In lean rodents, feeding or duodenal infusion of Intralipid® or pure oleic acid stimulates jejunal OEA mobilization. This response is strikingly absent in DIO rats and mice. Confirming previous reports, we found that feeding rats or mice a high-fat diet for 7 days is sufficient to suppress jejunal OEA mobilization. Surprisingly, a similar effect is elicited by feeding rats and mice a high-sucrose low-fat diet for 7 days. Collectively, our findings suggest that high fat-induced obesity is accompanied by alterations in the post-digestive machinery responsible for OEA biosynthesis, which may contribute to reduced satiety and hyperphagia.

Chocolate-candy consumption and 3-year weight gain among postmenopausal U.S. women

OBJECTIVE

To test the hypothesis that greater chocolate-candy intake is associated with more weight gain in postmenopausal women.

METHODS

A prospective cohort study involved 107,243 postmenopausal American women aged 50-79 years (mean = 60.7) at enrollment in the Women's Health Initiative, with 3-year follow-up. Chocolate-candy consumption was assessed by food frequency questionnaire, and body weight was measured. Linear mixed models, adjusted for demographic, socio economic, anthropomorphic, and behavioral variables, were used to test our main hypotheses.

RESULTS

Compared with women who ate a 1 oz (∼28 g) serving of chocolate candy <1 per month, those who ate this amount 1 per month to <1 per week, 1 per week to < 3 per week and ≥3 per week showed greater 3-year prospective weight gains (kg) of 0.76 (95% CI: 0.66, 0.85), 0.95 (0.84, 1.06), and 1.40 (1.27, 1.53), respectively, (P for linear trend<0.0001). Each additional 1 oz/day was associated with a greater 3-year weight gain (kg) of 0.92 (0.80, 1.05). The weight gain in each chocolate-candy intake level increased as BMI increased above the normal range (18.5-25 kg/m(2)), and was inversely associated with age.

CONCLUSIONS

Greater chocolate-candy intake was associated with greater prospective weight gain in this cohort of postmenopausal women.