Effects of caffeine chewing gum supplementation on exercise performance: A systematic review and meta-analysis.

The aim of this systematic review with meta-analysis was to determine the effect of caffeine gum (Caff-gum) on exercise performance-related outcomes. Several databases were searched for studies assessing the effect of Caff-gum in placebo-controlled protocols involving healthy adults. Random-effects meta-analyses using standardized mean differences (SMD) were performed to determine the effect of Caff-gum on exercise outcomes with several sub-analyses (training status, exercise type, timing and dose) for potential modifying factors. 14 studies were included, totalling 200 participants. There was a significant overall effect of Caff-gum compared to placebo (SMD = 0.21, 95%CI: 0.10-0.32; p = 0.001). Subgroup analysis showed improved performance for trained (SMD = 0.23, 95%CI: 0.08-0.37; p = 0.004), but not for untrained (SMD = 0.14, 95%CI: -0.02-0.29; p = 0.07) individuals. Caff-gum improved both endurance (SMD = 0.27, 95%CI: 0.12-0.42; p = 0.002) and strength/power (SMD = 0.20, 95%CI: 0.03-0.37; p = 0.03) performance outcomes. Caff-gum was ergogenic when consumed within 15 min prior to initiating exercise (SMD = 0.27, 95%CI: 0.07-0.4; p = 0.01), but not when provided >15 min prior (SMD = -0.48, 95%CI = -1.7-0.82; p = 0.25). There was no significant effect of Caff-gum with doses <3 mg/kg body mass (BM) (SMD = 0.20, 95%CI: -0.03-0.43; p = 0.07), but there was a significant effect when the dose was ≥3 mg/kg BM (SMD = 0.22, 95%CI: 0.07-0.37; p = 0.01). Caff-gum supplementation may be an effective ergogenic strategy for trained athletes involved in both endurance and strength/power exercise, using a recommended dose of ≥3 mg/kg BM consumed within 15 min of initiating exercise.HighlightsThis study determined the effect of Caff-gum on exercise performance, using a systematic review and meta-analysis. Fourteen studies, totalling 200 participants performing a variety of endurance and strength/power exercise tests were included. The relative Caff-gum dose ranged from 1.27-4.26 mg/kg BM and timing ranged from 120 min prior to exercise up to intra-test application.Caff-gum was shown to be an effective ergogenic aid for trained individuals involved in both endurance and strength/power exercise.Supplement dose and timing modified the efficacy of Caff-gum. Supplementation with Caff-gum was effective when provided in doses ≥3 mg/kg BM and within 15 min prior to initiating exercise.Trained endurance or strength/power athletes seeking to benefit from caffeine in the form of chewing gum should supplement within 15 min prior to initiating an exercise task, in doses ≥3 mg/kg BM.

Ground roasted peanuts leads to a lower post-prandial glycemic response than raw peanuts.

INTRODUCTION: Few studies have evaluated the effect of nuts processing on the glycemic response and satiety. OBJECTIVE: To evaluate the effect of peanut processing on glycemic response, and energy and nutrients intake. METHOD: Thirteen healthy subjects (4 men and 9 women), with a mean age of 28.5 ± 10 years, BMI 22.7 ± 2.5 kg/m², and body fat 23.7 ± 5.7% participated in this randomized crossover clinical trial. After 10-12 h of fasting, one of the following types of test meals were consumed: raw peanuts with skin (RPS), roasted peanuts without skin, ground-roasted peanuts without skin (GRPWS) or control meal. The test meals had the same nutrient composition, and were consumed with 200 ml of water in 15 minutes. Glycemic response was evaluated 2 hours after each meal. Energy and nutrients intake were assessed through diet records reflecting the habitual food intake and food consumption 24 hours after the ingestion of test meal. RESULT: The area under the glycemic response curve after GRPWS was lower (p = 0.02) the one obtained for RPS. There was no treatment effect on energy intake, macronutrients and fiber consumption after the test meal. CONCLUSION: The consumption of ground-roasted peanuts may favor the control and prevention of diabetes due to its reduction on postprandial glucose response. However, more prospective studies are needed to confirm this hypothesis.

Effect of the diet components on adiponectin levels.

The prevalence of obesity has reached epidemic proportions worldwide, which requires nutritional interventions for its effective control. Adiponectin has antiinflammatory capacity, improves glucose tolerance and presents decreased plasma expression and concentration in obese individuals. Studies with animals reveal improvement in insulin resistance after the infusion of adiponectin; in humans, caloric restriction increases its levels. The present study aimed to analyze the effects of dietary components on gene expression and plasma concentration of adiponectin. Sixteen articles were found following a literature review--seven with interventions in animal models and nine in human. The results in animal models demonstrate that the consumption of hyperlipidemic diets, rich in saturated fat, reduces the levels of adiponectin, while the diets rich in polyunsaturated fatty acids and supplementation with omega-3 and eicosapentaenoic acid increase its gene expression and plasma levels. In humans, the consumption of a healthy and Mediterranean diet are positively associated with adiponectin levels, although the mechanisms are not fully understood. Due to the importance of adiponectin in preventing metabolic diseases and reducing cardiovascular risk, more research are needed on food strategies to promote the increase of adiponectin levels. Therefore, studies must be carried out to evaluate the response to different sources and levels of various dietary components and the safety of the supplementation of specific nutrients.