Acute exercise effects on postprandial fat oxidation: meta-analysis and systematic review

Postprandial energy metabolism is modulated in response to a low-intensity walking exercise in fasted healthy individuals

Postprandial metabolism is a relevant indicator of overall metabolic health, which can be influenced by a single bout of exercise before food consumption. The present study examined the effects of an acute, fasted, low-intensity exercise on postprandial metabolism and appetite sensations. We hypothesized that exercise would induce an increase in postprandial fat oxidation, associated with better satiety responses. Twenty-two healthy adults (16 females) attended the laboratory twice separated by a minimum of 3 days to perform 2 conditions: (1) a control condition and (2) an exercise condition (EX) with a 30-minute low-intensity walking exercise performed before the breakfast (500-kcal fixed meal). Subjective appetite sensations were assessed before and up to 60 minutes after the meal in regular intervals. Energy expenditure and substrate oxidation were measured until 2 hours after the meal. Energy expenditure and carbohydrate oxidation were higher in the EX condition (condition effect: P < .01). There was no effect of exercise on appetite sensations and overall fat oxidation, but a higher increase in relative and absolute fat oxidation was observed from 15- to 45-minutes postmeal in EX compared with control (time × condition interaction effect: P < .05). In the EX condition only, postprandial satiety was associated positively with postprandial fat oxidation and negatively with carbohydrate oxidation. To conclude, a fasted low-intensity exercise induced an enhancement of postprandial metabolic flexibility through the modulation of fat oxidation. Substrate oxidation appeared to be related to satiety only after exercise, suggesting a specific regulation of appetite induced by exercise.

Metabolic responses to acute sprint interval exercise training performed after an oral 75-gram glucose load in individuals with overweight/obesity

There is evidence supporting that acute sprint interval training (SIT) might improve metabolic responses to postprandial glucose, but results are inconclusive. The aim of the present study was to explore the effects of acute SIT on metabolic response and substrate utilization in individuals with overweight/obesity after an oral 75-gram glucose challenge. Thirty-three participants with overweight/ obesity (32.7 ± 8.3 years, 24 male, 9 female) participated in the study and a crossover design was followed. After the 75-gram glucose load, participants were randomly allocated to two groups: no exercise (resting) or SIT protocol. Metabolic data including respiratory quotient (RQ) and substrate utilization rates (fats and carbohydrates) were collected using the COSMED Q-NRG + ® calorimeter. The RQ was significantly lower in the acute SIT group (0.76 [0.01]; p < 0.0001) than in the resting group (0.80 [0.01]; p = 0.036) at the 120-min postprandial time point, and the RQ area under the curve (AUC) was also lower in the SIT group (mean difference of -6.62, 95% CI -12.00 to -1.24; p = 0.0161). The contribution of fat to energy expenditure increased after SIT during the postprandial period whereas the contribution of carbohydrates decreased. The AUC for fat contribution was significantly higher (mean difference 2311.9, 95% confidence interval [CI] 578.8 to 4043.3; p = 0.0098) and the AUC for carbohydrate contribution was significantly lower (mean difference -2283.1, 95% CI -4040.2 to -527.1; p = 0.0117) in the SIT group than in the resting group. In conclusions, acute SIT might have a positive effect on metabolic responses to postprandial glucose and, accordingly, should be recommended for improving metabolism in people with overweight/obesity.

Oral contraceptive pill and metabolic syndrome: Fasa Persian Cohort Study (Descriptive study)

BACKGROUND AND AIMS

The contraceptive use is 56% and prevalence of metabolic syndrome (MetS) is 30% in Iran. The aim of this study investigates relationship between oral contraceptive pills (OCP) use and MetS in women in the cohort population of Fasa city.

METHODS

In a cross-sectional study, 5489 women aged 35-70 years were studied for 5 years in the Sheshdeh area in 2016. MetS were calculated using adult treatment panel III (ATP III) and international diabetes federation (IDF) methods. The odds ratio (OR) with a 95% confidence interval (CI) was reported. Linear regression was used to eliminate the confounding effect.

RESULTS

The OR of developing MetS in the OCP recipients was estimated as higher than the non-recipients. The OR of developing MetS using IDF criteria in OCP recipients was (OR = 0.896,95% CI:0.800-1.004). that increased to (OR = 1.230,95% CI:1.084-1.395) after adjusting for confounding variables. Also, the odds ratio using ATP (III) criteria was (OR = 0.900,95% CI:0.804-1.009). that increased to (OR = 1.245,95% CI:1.098-1.413) after adjusting for confounding variables. Also, the OR of developing MetS in OCP recipients decreased with increasing the number of MetS components from 1.199 to 0.812,95% CI:0.771-1.864,0.467-1.413, but after adjustment, increased from 1.151 to 1.747,95% CI:0.733-1.805,0.815-3.746.

CONCLUSION

The results of the present study showed that the OR of developing MetS in OCP recipients using both IDF and ATP (III) methods was higher after adjusting by confounder effects so it is recommended monitoring by physicians.