Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial

<p>Abstract</p> <p>Background</p> <p>The consumption of low glycemic index (LGI) foods before exercise results in slower and more stable glycemic increases. Besides maintaining an adequate supply of energy during exercise, this response may favor an increase in fat oxid...

Full description

Bibliographic Details
Main Authors: Bressan Josefina, Cecon Paulo R, Marins João CB, Pereira Letícia G, Cocate Paula G, Alfenas Rita CG
Format: Article
Language:English
Published: BMC 2011-01-01
Series:Nutrition Journal
Online Access:http://www.nutritionj.com/content/10/1/1
id doaj-d583292072af48a990f7edca947d179e
record_format Article
spelling doaj-d583292072af48a990f7edca947d179e2020-11-24T21:46:03ZengBMCNutrition Journal1475-28912011-01-01101110.1186/1475-2891-10-1Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trialBressan JosefinaCecon Paulo RMarins João CBPereira Letícia GCocate Paula GAlfenas Rita CG<p>Abstract</p> <p>Background</p> <p>The consumption of low glycemic index (LGI) foods before exercise results in slower and more stable glycemic increases. Besides maintaining an adequate supply of energy during exercise, this response may favor an increase in fat oxidation in the postprandial period before the exercise compared to high glycemic index (HGI) foods. The majority of the studies that evaluated the effect of foods differing in glycemic index on substrate oxidation during the postprandial period before the exercise are acute studies in which a single meal is consumed right before the exercise. The purpose of this study was to investigate the effect of consuming two daily HGI or LGI meals for five consecutive days on substrate oxidation before the exercise and in the concentrations of glucose, insulin and free fatty acids before and during a high intensity exercise.</p> <p>Methods</p> <p>Fifteen male cyclists, aged 24.4 ± 3.8 years, with body mass index of 21.9 ± 1.4 kg.m<sup>-2 </sup>and a V<sub>O2 max </sub>of 70.0 ± 5.3 mL.kg<sup>-1</sup>.min<sup>-1</sup>, participated in this crossover study. All test meals were consumed in the laboratory. On days 1 and 5, substrate oxidation (30 minutes before and 90 minutes after breakfast (HGI or LGI)) and diet-induced thermogenesis (90 minutes postprandial) were assessed before the exercise. The levels of glucose, insulin, and free fatty acids were determined during 2 h after breakfast on these same days. Ninety minutes after breakfast, subjects completed a 30 min cycloergometric exercise at 85 to 95% of their maximum heart rate, during which lactate concentrations were assessed.</p> <p>Results</p> <p>The consumption of HGI meals resulted in higher areas under the glycemic and insulinemic curves in the postprandial period. However, glycemia did not differ by study treatment during exercise. There were no differences in free fatty acids in the postprandial period or in lactate levels during exercise. LGI meals resulted in lower fat oxidation and higher carbohydrate oxidation than the HGI meal in the postprandial period.</p> <p>Conclusions</p> <p>The results do not support a differential glycemia according to glycemic index during exercise. The ingestion of LGI foods did not lead to higher fat oxidation relative to the ingestion of HGI foods.</p> <p>Trial registration</p> <p>ACTRN: <a href="http://www.anzctr.org.au/ACTRN12609000522213.aspx">ACTRN12609000522213</a></p> http://www.nutritionj.com/content/10/1/1
collection DOAJ
language English
format Article
sources DOAJ
author Bressan Josefina
Cecon Paulo R
Marins João CB
Pereira Letícia G
Cocate Paula G
Alfenas Rita CG
spellingShingle Bressan Josefina
Cecon Paulo R
Marins João CB
Pereira Letícia G
Cocate Paula G
Alfenas Rita CG
Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
Nutrition Journal
author_facet Bressan Josefina
Cecon Paulo R
Marins João CB
Pereira Letícia G
Cocate Paula G
Alfenas Rita CG
author_sort Bressan Josefina
title Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
title_short Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
title_full Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
title_fullStr Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
title_full_unstemmed Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
title_sort metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial
publisher BMC
series Nutrition Journal
issn 1475-2891
publishDate 2011-01-01
description <p>Abstract</p> <p>Background</p> <p>The consumption of low glycemic index (LGI) foods before exercise results in slower and more stable glycemic increases. Besides maintaining an adequate supply of energy during exercise, this response may favor an increase in fat oxidation in the postprandial period before the exercise compared to high glycemic index (HGI) foods. The majority of the studies that evaluated the effect of foods differing in glycemic index on substrate oxidation during the postprandial period before the exercise are acute studies in which a single meal is consumed right before the exercise. The purpose of this study was to investigate the effect of consuming two daily HGI or LGI meals for five consecutive days on substrate oxidation before the exercise and in the concentrations of glucose, insulin and free fatty acids before and during a high intensity exercise.</p> <p>Methods</p> <p>Fifteen male cyclists, aged 24.4 ± 3.8 years, with body mass index of 21.9 ± 1.4 kg.m<sup>-2 </sup>and a V<sub>O2 max </sub>of 70.0 ± 5.3 mL.kg<sup>-1</sup>.min<sup>-1</sup>, participated in this crossover study. All test meals were consumed in the laboratory. On days 1 and 5, substrate oxidation (30 minutes before and 90 minutes after breakfast (HGI or LGI)) and diet-induced thermogenesis (90 minutes postprandial) were assessed before the exercise. The levels of glucose, insulin, and free fatty acids were determined during 2 h after breakfast on these same days. Ninety minutes after breakfast, subjects completed a 30 min cycloergometric exercise at 85 to 95% of their maximum heart rate, during which lactate concentrations were assessed.</p> <p>Results</p> <p>The consumption of HGI meals resulted in higher areas under the glycemic and insulinemic curves in the postprandial period. However, glycemia did not differ by study treatment during exercise. There were no differences in free fatty acids in the postprandial period or in lactate levels during exercise. LGI meals resulted in lower fat oxidation and higher carbohydrate oxidation than the HGI meal in the postprandial period.</p> <p>Conclusions</p> <p>The results do not support a differential glycemia according to glycemic index during exercise. The ingestion of LGI foods did not lead to higher fat oxidation relative to the ingestion of HGI foods.</p> <p>Trial registration</p> <p>ACTRN: <a href="http://www.anzctr.org.au/ACTRN12609000522213.aspx">ACTRN12609000522213</a></p>
url http://www.nutritionj.com/content/10/1/1
work_keys_str_mv AT bressanjosefina metabolicresponsestohighglycemicindexandlowglycemicindexmealsacontrolledcrossoverclinicaltrial
AT ceconpaulor metabolicresponsestohighglycemicindexandlowglycemicindexmealsacontrolledcrossoverclinicaltrial
AT marinsjoaocb metabolicresponsestohighglycemicindexandlowglycemicindexmealsacontrolledcrossoverclinicaltrial
AT pereiraleticiag metabolicresponsestohighglycemicindexandlowglycemicindexmealsacontrolledcrossoverclinicaltrial
AT cocatepaulag metabolicresponsestohighglycemicindexandlowglycemicindexmealsacontrolledcrossoverclinicaltrial
AT alfenasritacg metabolicresponsestohighglycemicindexandlowglycemicindexmealsacontrolledcrossoverclinicaltrial
_version_ 1725902317691076608