include increased oxidative stress and inflammation ( Alipour et al., 2008 ; Devaraj et al., 2008 ). The adverse metabolic response to an HFM is characterized by significantly elevated plasma triglycerides (TG), known as postprandial lipemia (PPL). The magnitude of this TG response is directly associated
Nicholas A. Koemel, Christina M. Sciarrillo, Katherine B. Bode, Madison D. Dixon, Edralin A. Lucas, Nathaniel D.M. Jenkins, and Sam R. Emerson
Keith Tolfrey, Alice Emily Thackray, and Laura Ann Barrett
Exaggerated postprandial triacylglycerol concentrations (TAG) independently predict future cardiovascular events. Acute exercise and diet interventions attenuate postprandial TAG in adults. This paper aims to examine the exercise postprandial lipemia studies published to date in young people. Nine studies satisfied the inclusion criteria adopted for this summary. The majority of studies are in boys (22% girls) and have shown a single ~60-min session of moderate-intensity exercise, performed 12-18 hours before a standardized meal, reduces postprandial TAG. Manipulations of exercise duration and intensity suggest an exercise energy expenditure dose-dependent response is not supported directly in healthy young people. Studies investigating alternative exercise bouts have reported lower postprandial TAG after simulated intermittent games activity, high-intensity interval running and cumulative 10-min blocks over several hours, which may appeal to the spontaneous physical activity habits of young people. Although extension of these initial findings is warranted, exercise may be an effective strategy to promote regular benefits in TAG metabolism in children and adolescents; this may contribute to an improved cardiovascular disease risk profile early in life.
Richard J. Bloomer, Bradford Cole, and Kelsey H. Fisher-Wellman
High-kilocalorie feedings induce oxidative stress. Acute exercise has the potential to attenuate postprandial oxidative stress. No study has determined whether there are racial differences in postprandial oxidative stress with and without a preceding bout of acute exercise.
To investigate the impact of acute exercise on blood oxidative- stress biomarkers, triglycerides (TAG), and glucose in African American (AA) and White (W) women.
10 AA (age 29 ± 3 yr, body-mass index [BMI] 31 ± 3 kg/m2) and 10 W (age 30 ± 2 yr, BMI 30 ± 3 kg/m2) women consumed a meal of 1.2 g of fat and carbohydrate and 0.25 g of protein per kilogram body mass, on 2 occasions—with and without a session of aerobic exercise 15 min preceding the meal (45 min cycling at 65% heart-rate reserve)—in a random-order crossover design. Blood samples were collected premeal (fasted), and at 1, 2, 4, and 6 hr postmeal and assayed for TAG, glucose, xanthine oxidase activity, hydrogen peroxide (H2O2), and malondialdehyde (MDA). Area under the curve (AUC) was calculated for each variable.
AUC was lower for AA compared with W for both the exercise and the no exercise conditions for H2O2, MDA, and TAG (p < .01). However, acute exercise had no effect on decreasing the AUC for any variable in either AA or W women (p > .05).
Postprandial lipemia and oxidative stress are lower in AA than in W overweight/obese women. However, acute exercise, performed at the intensity and duration in the current study, does not influence postprandial lipemia or oxidative stress in AA or W women.
Keith A. Shannon, Robynn M. Shannon, John N. Clore, Chris Gennings, Beverly J. Warren, and Jeffrey A. Potteiger
To determine whether ethnicity influences postprandial lipemia after a bout of aerobic exercise.
Randomized crossover design. Healthy White (W; n = 6) and African American (AA; n = 6) women (age, W 27.0 ± 3.3 yr, AA 21.6 ± 1.4 yr; body-mass index, W 25.0 ± 0.93 kg/m2, AA 25.8 ± 0.79 kg/m2) participated in 2 treatments (control and exercise), each conducted over 2 d. On d 1, participants rested (control) or walked at 60% of maximal oxygen uptake for 90 min (exercise) and then consumed a meal. On d 2, after a 12-hr overnight fast, participants consumed an oral fat-tolerance test (OFTT) meal of 1.7 g fat, 1.65 g carbohydrate, and 0.25 g protein per kg fat-free mass. Blood was collected premeal and at 0.5, 1, 2, 3, 4, 5, and 6 hr post-OFTT and analyzed for triacylglycerol (TAG), glucose, and insulin. Areas under the curve (AUCs) were calculated for each blood variable.
A significantly lower TAG AUC was observed for AA (0.86 ± 0.24 mmol · L−1 · 6 hr−1) after exercise than for W (2.25 ± .50 mmol · L−1 · 6 hr−1). Insulin AUC was significantly higher for AA after exercise (366.2 ± 19.9 mmol · L−1 · 6 hr−1) than for the control (248.1 ± 29.2 mmol · L−1 · 6 hr−1).
The data indicate that exercise performed ~13 hr before an OFTT significantly reduces postprandial lipemia in AA compared with W. It appears that AA women have an increased ability to dispose of TAG after exercise and a high-fat meal.
James R. Rowe, Kyle D. Biggerstaff, Vic Ben-Ezra, David L. Nichols, and Nancy DiMarco
This study examined the effect of prior exercise on postprandial lipemia (PPL) concentration following a mixed meal (MM) made with either glucose or fructose. Sedentary women completed four trials in random order: 1) Rest-Fructose: RF, 2) Rest-Glucose: RG, 3) Exercise-Fructose: EF, 4) Exercise-Glucose: EG. Exercise expended 500 kcal while walking at 70%VO2max. Rest was 60 min of sitting. The morning after each trial, a fasting (12 hr) blood sample was collected followed by consumption of the MM. The MM was blended with whole milk and ice cream plus a glucose or fructose powder. Glucose and fructose powder accounted for 30% of the total kcal within the MM. Blood was collected periodically for 6 hr post-MM and analyzed for PPL. Magnitude of PPL over the 6 hr postmeal was quantified using the triglyceride incremental area under the curve (TG AUCI). Significant differences (p < .05) between trials were determined using repeated-measures ANOVA and Bonferroni post hoc test. There was no significant difference in the TG AUCI between the four trials (p > .05). A significant trial by time interaction for TG concentration was reported (p < .05). Despite lack of change in the AUCI with prior exercise, the lower TG concentration at multiple time points in the EG trial does indicate that prior exercise has some desirable effect on PPL. This study suggests that replacing fructose with glucose sugars and incorporating exercise may minimize PPL following a mixed meal but exercise will need to elicit greater energy expenditure.
Joel B. Mitchell, James R. Rowe, Meena Shah, James J. Barbee, Austen M Watkins, Chad Stephens, and Steve Simmons
To examine the effect of prior exercise on the postprandial lipid response to a high-carbohydrate meal in normal-weight (NW = BMI h25) and overweight (OW = BMI ≥25) women (age 18–25), 10 NW and 10 OW participants completed 2 conditions separated by 1 month. In the morning, the day after control (CT = no exercise) or exercise conditions (EX = 60 min cycling at 60% VO2peak), participants consumed a high-carbohydrate meal (80% CHO, 15% protein, 5% fat; 75 kJ/kg BM) followed by 6 hr of hourly blood sampling. Blood was analyzed for triglycerides (TG), blood glucose (BG), and insulin (IN). TG levels over the 6-hr period were lower in NW than OW (p = .021) and lower in EX than in CT (p = .006). Area under the curve (AUC) for TG was lower in NW than OW (p = .016) and EX than CT (p = .003). There were nonsignificant tendencies for reduced BG over time (p = .053) and AUC (p = .083), and IN AUC was lower in EX than in CT (p = .040) for both groups and lower in NW than in OW (p = .039). Prior exercise improved TG levels after a high-carbohydrate meal in both groups, and OW women demonstrated a greater postprandial lipemic response than NW regardless of condition. There were tendencies for improved glucose removal with prior exercise in NW vs. OW. Acute exercise can improve postprandial TG responses and might also improve postprandial BG and IN after a large meal in NW and OW young women.
Masashi Miyashita, Stephen F. Burns, and David J. Stensel
The current study investigated the acute effects of accumulating short bouts of running on circulating concentrations of postprandial triacylglycerol (TAG) and C-reactive protein (CRP). Ten men, age 21–32 yr, completed two 1-d trials. On 1 occasion participants ran at 70% of maximum oxygen uptake in six 5-min bouts (i.e., 8:30, 10, and 11:30 a.m. and 1, 2:30, and 4 p.m.) with 85 min rest between runs. On another occasion participants rested throughout the day. In both trials, participants consumed test meals at 9 a.m. and 12 p.m. In each trial, venous blood samples were collected at 8:30, 10, and 11:30 a.m. and 1, 2:30, 4, and 5:30 p.m. for plasma TAG measurement and at 8:30 a.m. and 5:30 p.m. for serum CRP measurement. Total area under the curve for plasma TAG concentration versus time was 10% lower on the exercise trial than the control trial (M ± SEM: 13.5 ± 1.8 vs. 15.0 ± 1.9 mmol · 9 hr−1 · L−1; p = .004). Serum CRP concentrations did not differ between trials or over time. This study demonstrates that accumulating short bouts of running reduces postprandial plasma TAG concentrations (a marker for cardiovascular disease risk) but does not alter serum CRP concentrations.
Stephen F. Burns, Keith Shannon, and Jeffrey Potteiger
Martin Tan, Rachel Chan Moy Fat, Yati N. Boutcher, and Stephen H. Boutcher
High-intensity intermittent exercise (HIIE) such as the 30-s Wingate test attenuates postprandial triacylglycerol (TG), however, the ability of shorter versions of HIIE to reduce postprandial TG is undetermined. Thus, the effect of 8-s sprinting bouts of HIIE on blood TG levels of 12 females after consumption of a high-fat meal (HFM) was examined. Twelve young, sedentary women (BMI 25.1 ± 2.3 kg/m2; age 21.3 ± 2.1 years) completed a maximal oxygen uptake test and then on different days underwent either an exercise or a no-exercise postprandial TG condition. Both conditions involved consuming a HFM after a 12-hr fast. The HFM, in milkshake form provided 4170 kJ (993 Kcal) of energy and 98 g fat. Order was counter-balanced. In the exercise condition participants completed 20-min of HIIE cycling consisting of repeated bouts of 8 s sprint cycling (100–115 rpm) and 12 s of active rest (easy pedaling) 14 hr before consuming the HFM. Blood samples were collected hourly after the HFM for 4 hr. Total postprandial TG was 13% lower, p = .004, in the exercise (5.84 ± 1.08 mmol L−1 4 h−1) compared with the no-exercise condition (6.71 ± 1.63 mmol L−1 4 h−1). In conclusion, HIIE significantly attenuated postprandial TG in sedentary young women.
Alice Emily Thackray, Laura Ann Barrett, and Keith Tolfrey
Eleven healthy girls (mean ± SD: age 12.1 ± 0.6 years) completed three 2-day conditions in a counterbalanced, crossover design. On day 1, participants either walked at 60 (2)% peak oxygen uptake (energy deficit 1.55[0.20] MJ), restricted food energy intake (energy deficit 1.51[0.25] MJ) or rested. On day 2, capillary blood samples were taken at predetermined intervals throughout the 6.5 hr postprandial period before, and following, the ingestion of standardized breakfast and lunch meals. Fasting plasma triacylglycerol concentrations (TAG) was 29% and 13% lower than rest control in moderate-intensity exercise (effect size [ES] = 1.39, p = .01) and energy-intake restriction (ES = 0.57, p = .02) respectively; moderate-intensity exercise was 19% lower than energy-intake restriction (ES = 0.82, p = .06). The moderate-intensity exercise total area under the TAG versus time curve was 21% and 13% lower than rest control (ES = 0.71, p = .004) and energy-intake restriction (ES = 0.39, p = .06) respectively; energy-intake restriction was marginally lower than rest control (-10%; ES = 0.32, p = .12). An exercise-induced energy deficit elicited a greater reduction in fasting plasma TAG with a trend for a larger attenuation in postprandial plasma TAG than an isoenergetic diet-induced energy deficit in healthy girls.