Efficacité du jeûne intermittent chez les bodybuildeuses?

[Nutrimuscle-Conseils]

The effect of moderate intermittent versus continuous energy restriction on body composition and resting metabolic rate in resistance-trained females: A randomized controlled trial
Madelin R. Siedler,Journal of the International Society of Sports Nutrition 2020 A8.

Background

Moderate intermittent energy restriction (mIER) entails intermittent, sustained increases in energy intake over the course of a prolonged period of energy restriction. Previous research in men with obesity suggests that mIER may improve the efficiency of fat loss and reduce metabolic adaptations to prolonged energy restriction, while other studies in similar populations show no effect. The purpose of this study was to examine the effects of mIER versus continuous energy restriction in a population of resistance-trained females.

Materials and Methods

38 resistance-trained females (age: 22.3 ±4.2 years; height 1.6 ±0.7m) participated in this study. Subjects were randomized to either continuous dieting (idiot; n = 18) or intermittent dieting (INT; n = 20). Participants in idiot were prescribed 6 weeks of a continuous 25% reduction in energy intake. Participants in INT were prescribed 1 week of energy intake at maintenance levels after every 2 weeks of 25% energy restriction (8 weeks total). Subjects were instructed to ingest 1.8 g protein/kg bodyweight and took part in 3 weekly supervised resistance training sessions. Body weight, body composition, and resting metabolic rate (RMR) was assessed pre and post-intervention. Data were analyzed using a series of linear mixed models with random intercepts.

Results

Across all subjects from PRE to POST, there was a mean decrease in body weight (62.7 ±9 kg to 61.5 ±9.2 kg; [p = 0.0002]); percent body fat (25 ±4.4% to 23.6 ±4.8%; [p < 0.0001]), and fat mass (15.9 ±4.6 kg to 14.7 ±4.6kg; [p < 0.0001]). Fat-free mass (46.8 ±5.2 kg to 46.8 ±5.7; p = 0.90) and RMR (1422 ±193 kcal to 1434 ±190 kcal; p = 0.48) did not change from PRE to POST. There were no significant differences between groups for all body composition variables and RMR.

Conclusions

In resistance trained females seeking to optimize their physiques, mIER does not improve the efficiency of fat loss and has no effect on FFM and RMR. Incorporating mIER dieting strategies may be employed for those whom desire a short-term break from an energy-restricted diet without fear of impairing fat loss progress.

[Nutrimuscle-Conseils]

The effect of moderate intermittent versus continuous energy restriction on body composition on hunger and eating behaviors in resistance-trained females: A randomized controlled trial
Madelin R. Siedler, Journal of the International Society of Sports Nutrition 2020 A9.

Background

Moderate intermittent energy restriction (mIER) entails intermittent, sustained increases in energy intake over the course of a prolonged period of energy restriction. The purpose of this study (among others) was to examine the effects of mIER versus continuous energy restriction on eating behaviors in a population of resistance-trained females.

Materials and Methods

38 resistance-trained females (age: 22.3±4.2 years; height 1.6±0.7m) participated in this study. Subjects were randomized to either continuous dieting (idiot; n=18) or intermittent dieting (INT; n=20). Participants in idiot were prescribed 6 weeks of a continuous 25% reduction in energy intake. Participants in INT were prescribed 1 week of energy intake at maintenance levels after every 2 weeks of 25% energy restriction (8 weeks total). Subjects were instructed to ingest 1.8 g protein/kg bodyweight and took part in 3 weekly supervised resistance training sessions. At baseline (PRE) and post-intervention (POST), eating behavior was measured via a 51-item three-factor eating questionnaire (TFEQ) which measures an individual’s level of hunger, disinhibition (the loss of control in food intake), and dietary restraint (degree of cognitive control) in daily food intake. Data were analyzed using a series of linear mixed models with random intercepts.

Results

Across all subjects, level of dietary restraint did not change from PRE to POST (p = 0.39), nor did level of hunger (p = 0.66). While there were no differences between groups for change over time in these variables (p = 0.20 and p = 0.21, respectively), there was a significant group-by-time interaction for disinhibition (p = 0.03). While no pairwise comparisons were significantly different, a divergent pattern was observed, with mean values for disinhibition generally increasing from PRE to POST in idiot (5.17±2.07 to 5.83±1.79; p=0.52) but decreasing from PRE to POST in INT (6.85±3.76 to 6.00±3.58; p=0.26).

Conclusions

Though the use of mIER did not appear to affect changes in hunger or dietary restraint over 6 weeks of energy restriction, it may reduce the impact of prolonged energy restriction on measures of disinhibition, potentially helping to promote increased long-term dietary adherence.

[Nutrimuscle-Diététique]

Traduction de l'étude

L'effet d'une restriction énergétique intermittente modérée ou continue sur la composition corporelle sur la faim et les comportements alimentaires chez les femmes entraînées par la résistance: un essai contrôlé randomisé
Madelin R. Siedler, Journal de la Société internationale de nutrition sportive 2020 A9.

Contexte

La restriction énergétique intermittente modérée (mIER) entraîne des augmentations intermittentes et soutenues de l'apport énergétique au cours d'une période prolongée de restriction énergétique. Le but de cette étude (entre autres) était d'examiner les effets de mIER par rapport à la restriction énergétique continue sur les comportements alimentaires dans une population de femmes entraînées à la résistance.

Matériaux et méthodes

38 femmes entraînées en résistance (âge: 22,3 ± 4,2 ans; taille 1,6 ± 0,7 m) ont participé à cette étude. Les sujets ont été randomisés pour suivre un régime continu (idiot; n = 18) ou un régime intermittent (INT; n = 20). Les participants à l'idiot se sont vu prescrire 6 semaines d'une réduction continue de 25% de leur apport énergétique. Les participants à l'INT se sont vu prescrire 1 semaine d'apport énergétique à des niveaux d'entretien toutes les 2 semaines de restriction énergétique de 25% (8 semaines au total). Les sujets ont reçu pour instruction d'ingérer 1,8 g de protéines / kg de poids corporel et ont participé à 3 séances d'entraînement de résistance supervisées par semaine. Au départ (PRE) et après l'intervention (POST), le comportement alimentaire a été mesuré via un questionnaire alimentaire à trois facteurs à 51 points (TFEQ) qui mesure le niveau de faim d'un individu, de désinhibition (la perte de contrôle de la prise alimentaire) et la restriction alimentaire (degré de contrôle cognitif) dans l'apport alimentaire quotidien. Les données ont été analysées à l'aide d'une série de modèles mixtes linéaires avec des interceptions aléatoires.

Résultats

Pour tous les sujets, le niveau de contention alimentaire n'a pas changé de PRE à POST (p = 0,39), ni le niveau de faim (p = 0,66). Alors qu'il n'y avait pas de différences entre les groupes pour le changement au fil du temps de ces variables (p = 0,20 et p = 0,21, respectivement), il y avait une interaction groupe par temps significative pour la désinhibition (p = 0,03). Bien qu'aucune comparaison par paires ne soit significativement différente, un schéma divergent a été observé, les valeurs moyennes de désinhibition augmentant généralement de PRE à POST chez l'idiot (5,17 ± 2,07 à 5,83 ± 1,79; p = 0,52) mais diminuant de PRE à POST en INT (6,85 ± 3,76 à 6,00 ± 3,58; p = 0,26).

Conclusions
Bien que l'utilisation de mIER n'ait pas semblé affecter les changements de la faim ou de la restriction alimentaire sur 6 semaines de restriction énergétique, elle peut réduire l'impact d'une restriction énergétique prolongée sur les mesures de désinhibition, contribuant potentiellement à favoriser une meilleure observance alimentaire à long terme.