title: Enhanced vascular function after acute fat-rich snacking in healthy males.
abstract: Diets high in fat are associated with vascular dysfunction. Frequent snacking may exacerbate this problem by extending the postprandial state. We hypothesized that repeated fat-rich mixed snacks would impair peripheral endothelial function and increase oxidative stress, a purported causal factor. Second, we hypothesized that feeding a quantity of snack based on the subject's body size would not cause different effects from feeding a fixed or constant size snack. A crossover design was used where 10 healthy males followed 2 repeated-snack regimens (fixed and variable based on body surface area), 1 week apart. Each regimen consisted of 2 snacks, fed 4 hours apart (0 and 4 hours). Markers of vascular function (reactive hyperemia index [RHI]), oxidative stress, and antioxidant capacity were measured before and after each snack. Peripheral vascular function improved from fasting to 2 hours after snack 1 (RHI(2h-0h), P = .010), but the change before and after snack 2, RHI(6h-4h), was negative (P = .026), indicating reduced endothelial function after repeated snacking. The oxidative stress marker changed over time (P = .043), increasing after snack 1 and decreasing before snack 2, with no change after snack 2. The antioxidant marker increased 2 hours after each snack (P = .003). Responses to fixed snacks over time were not different from variable snacks, although power was low; the effect size was large for antioxidant capacity, medium for oxidative stress, and small for RHI. Snacking after fasting resulted in a transiently improved peripheral vascular response that disappeared with a second snack. Antioxidant capacity appeared to help limit oxidative stress from repeated snacking in these healthy male subjects.
authors.affiliation: Indiana University, Bloomington, IN 47405, USA.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Liu
authors.forename: David L
authors.initials: DL
authors.lastname: Daleke
authors.forename: Alyce D
authors.initials: AD
authors.lastname: Fly
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D049628:Body Size; D018592:Cross-Over Studies; D004032:Diet; D004041:Dietary Fats / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D002149:Energy Intake; D005215:Fasting; D006801:Humans; D006940:Hyperemia / Q000209:etiology; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D019518:Postprandial Period; D012016:Reference Values; D062410:Snacks / Q000502:physiology*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D004041:Dietary Fats