title: A putative low-carbohydrate ketogenic diet elicits mild nutritional ketosis but does not impair the acute or chronic hypertrophic responses to resistance exercise in rodents.
abstract: We examined whether acute and/or chronic skeletal muscle anabolism is impaired with a low-carbohydrate diet formulated to elicit ketosis (LCKD) vs. a mixed macronutrient Western diet (WD). Male Sprague-Dawley rats (9-10 wk of age, 300-325 g) were provided isoenergetic amounts of a LCKD or a WD for 6 wk. In AIM 1, basal serum and gastrocnemius assessments were performed. In AIM 2, rats were resistance exercised for one bout and were euthanized 90-270 min following exercise for gastrocnemius analyses. In AIM 3, rats voluntarily exercised daily with resistance-loaded running wheels, and hind limb muscles were analyzed for hypertrophy markers at the end of the 6-wk protocol. In AIM 1, basal levels of gastrocnemius phosphorylated (p)-rps6, p-4EBP1, and p-AMPKα were similar between diets, although serum insulin (P < 0.01), serum glucose (P < 0.001), and several essential amino acid levels (P < 0.05) were lower in LCKD-fed rats. In AIM 2, LCKD- and WD-fed rats exhibited increased postexercise muscle protein synthesis levels (P < 0.0125), but no diet effect was observed (P = 0.59). In AIM 3, chronically exercise-trained LCKD- and WD-fed rats presented similar increases in relative hind limb muscle masses compared with their sedentary counterparts (12-24%, P < 0.05), but there was no between-diet effects. Importantly, the LCKD induced "mild" nutritional ketosis, as the LCKD-fed rats in AIM 2 exhibited ∼1.5-fold greater serum β-hydroxybutyrate levels relative to WD-fed rats (diet effect P = 0.003). This study demonstrates that the tested LCKD in rodents, while only eliciting mild nutritional ketosis, does not impair the acute or chronic skeletal muscle hypertrophic responses to resistance exercise.
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama; Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, Alabama; and.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Roberts
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: A Maleah
authors.initials: AM
authors.lastname: Holland
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Wesley C
authors.initials: WC
authors.lastname: Kephart
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: C Brooks
authors.initials: CB
authors.lastname: Mobley
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Petey W
authors.initials: PW
authors.lastname: Mumford
authors.affiliation: Applied Science and Performance Institute, Tampa, Florida.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Lowery
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Carlton D
authors.initials: CD
authors.lastname: Fox
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Anna E
authors.initials: AE
authors.lastname: McCloskey
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Shake
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Paulo
authors.initials: P
authors.lastname: Mesquita
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama;
authors.forename: Romil K
authors.initials: RK
authors.lastname: Patel
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama; Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, Alabama; and.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Martin
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama; Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, Alabama; and.
authors.forename: Kaelin C
authors.initials: KC
authors.lastname: Young
authors.affiliation: Department of Kinesiology, Auburn University, Auburn, Alabama; Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, Alabama; and.
authors.forename: Andreas N
authors.initials: AN
authors.lastname: Kavazis
authors.affiliation: Applied Science and Performance Institute, Tampa, Florida jwlson@theaspi.com.
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Wilson
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism; D000601:Amino Acids, Essential / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism / Q000502:physiology; D050528:Diet, Carbohydrate-Restricted / Q000379:methods; D055423:Diet, Ketogenic / Q000379:methods; D004040:Dietary Carbohydrates / Q000378:metabolism*; D006614:Hindlimb / Q000378:metabolism / Q000503:physiopathology; D006984:Hypertrophy / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007662:Ketosis / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D055070:Resistance Training / Q000379:methods; D012377:Rodentia / Q000097:blood / Q000378:metabolism / Q000502:physiology
chemical_list: D000601:Amino Acids, Essential; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D020155:3-Hydroxybutyric Acid
keywords: AMPK; low-carbohydrate diets; muscle hypertrophy; muscle protein synthesis