Chronic Adherence to a Ketogenic Diet Modifies Iron Metabolism in Elite Athletes
Author(s)
Mckay, Alannah KA
Peeling, Peter
Pyne, David B
Welvaert, Marijke
Tee, Nicolin
Leckey, Jill J
Sharma, Avish P
Ross, Megan LR
Garvican-Lewis, Laura A
Swinkels, Dorine W
Laarakkers, Coby M
Burke, Louise M
Griffith University Author(s)
Year published
2019
Metadata
Show full item recordAbstract
PURPOSE:
The short-term restriction of carbohydrate (CHO) can potentially influence iron regulation via modification of postexercise interleukin-6 (IL-6) and hepcidin levels. This study examined the effect of a chronic ketogenic low-CHO high-fat (LCHF) diet on iron status and iron-regulatory markers in elite athletes.
METHODS:
International-level race walkers (n = 50) were allocated to one of three dietary interventions: (i) a high-CHO diet (n = 16), (ii) a periodized CHO availability (n = 17), or (iii) an LCHF diet (n = 17) while completing a periodized training program for 3 wk. A 19- to 25-km race walking test protocol ...
View more >PURPOSE: The short-term restriction of carbohydrate (CHO) can potentially influence iron regulation via modification of postexercise interleukin-6 (IL-6) and hepcidin levels. This study examined the effect of a chronic ketogenic low-CHO high-fat (LCHF) diet on iron status and iron-regulatory markers in elite athletes. METHODS: International-level race walkers (n = 50) were allocated to one of three dietary interventions: (i) a high-CHO diet (n = 16), (ii) a periodized CHO availability (n = 17), or (iii) an LCHF diet (n = 17) while completing a periodized training program for 3 wk. A 19- to 25-km race walking test protocol was completed at baseline and after adaptation, and changes in serum ferritin, IL-6, and hepcidin concentrations were measured. Results from high-CHO and periodized CHO were combined into one group (CHO; n = 33) for analysis. RESULTS: The decrease in serum ferritin across the intervention period was substantially greater in the CHO group (37%) compared with the LCHF (23%) group (P = 0.021). After dietary intervention, the postexercise increase in IL-6 was greater in LCHF (13.6-fold increase; 95% confidence interval [CI] = 7.1-21.4) than athletes adhering to a CHO-rich diet (7.6-fold increase; 95% CI = 5.5-10.2; P = 0.033). Although no significant differences occurred between diets, CI values indicate that 3 h postexercise hepcidin concentrations were lower after dietary intervention compared with baseline in CHO (β = -4.3; 95% CI = -6.6 to -2.0), with no differences evident in LCHF. CONCLUSION: Athletes who adhered to a CHO-rich diet experienced favorable changes to the postexercise IL-6 and hepcidin response, relative to the LCHF group. Lower serum ferritin after 3 wk of additional dietary CHO might reflect a larger more adaptive hematological response to training.
View less >
View more >PURPOSE: The short-term restriction of carbohydrate (CHO) can potentially influence iron regulation via modification of postexercise interleukin-6 (IL-6) and hepcidin levels. This study examined the effect of a chronic ketogenic low-CHO high-fat (LCHF) diet on iron status and iron-regulatory markers in elite athletes. METHODS: International-level race walkers (n = 50) were allocated to one of three dietary interventions: (i) a high-CHO diet (n = 16), (ii) a periodized CHO availability (n = 17), or (iii) an LCHF diet (n = 17) while completing a periodized training program for 3 wk. A 19- to 25-km race walking test protocol was completed at baseline and after adaptation, and changes in serum ferritin, IL-6, and hepcidin concentrations were measured. Results from high-CHO and periodized CHO were combined into one group (CHO; n = 33) for analysis. RESULTS: The decrease in serum ferritin across the intervention period was substantially greater in the CHO group (37%) compared with the LCHF (23%) group (P = 0.021). After dietary intervention, the postexercise increase in IL-6 was greater in LCHF (13.6-fold increase; 95% confidence interval [CI] = 7.1-21.4) than athletes adhering to a CHO-rich diet (7.6-fold increase; 95% CI = 5.5-10.2; P = 0.033). Although no significant differences occurred between diets, CI values indicate that 3 h postexercise hepcidin concentrations were lower after dietary intervention compared with baseline in CHO (β = -4.3; 95% CI = -6.6 to -2.0), with no differences evident in LCHF. CONCLUSION: Athletes who adhered to a CHO-rich diet experienced favorable changes to the postexercise IL-6 and hepcidin response, relative to the LCHF group. Lower serum ferritin after 3 wk of additional dietary CHO might reflect a larger more adaptive hematological response to training.
View less >
Journal Title
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
Volume
51
Issue
3
Subject
Sports science and exercise
Medical physiology
Health services and systems
Public health