PosterPDF Available

Effects of a 6-week Low-Carbohydrate High-Fat Diet on Lipid Profiles in Competitive Recreational Distance Runners

Authors:

Abstract

Low-Carbohydrate High-Fat (LCHF) diets have become very popular among athletes due to recent research suggesting performance and numerous health benefits. However, few studies have examined the chronic effects of LCHF diets on the blood lipid profile and other cardiovascular disease risk factors in athletic populations. PURPOSE: To examine the effect of a 6-week LCHF diet (69% kcals from fat, 6% carbohydrates), compared to a diet higher in carbohydrate and lower in fat (HCLF; 56% kcals from carbohydrate, 28% fat) on fasting lipids-triglycerides (TG), LDL-C, HDL-C, total cholesterol (TC), VLDL, TG/HDL-C Ratio, TC/HDL-C Ratio, glucose and glycated hemoglobin (HbA1c), in competitive recreational distance runners. METHODS: Seven male athletes (age 35.6 ± 8.4 years, height 178.7 ± 4.1 cm, weight 68.6 ± 1.6 kg; VO2max 61.9 ± 6.1 ml/kg/min) consumed an ad libitum LCHF and ad libitum HCLF diet in a random order, each for 6 weeks in a crossover design. Plasma lipids where measured on day 4, 14, 28, and 42 of each diet. RESULTS: The LCHF diet significantly increased TC (mean ± SD; LCHF 197.4 ± 26.3 mg/dl, HCLF 153.4 ± 1.3 mg/dl; %Diff = 25.1%; p = 0.001), LDL-C (LCHF 108.3 ± 20.6 mg/dl, HCLF 73.5 ± 2.8 mg/dl; %Diff = 38.3%; p = 0.001), HDL-C (LCHF 70.6 ± 3.5 mg/dl, HCLF 60.6 ± 2.1 mg/dl; %Diff = 15.3%; p = 0.015), and decreased TG (LCHF 73.9 ± 4.4 mg/dl, HCLF 97.0 ± 10.9 mg/dl; %Diff = 26.9%; p = 0.005), VLDL (LCHF 18.5 ± 3.5 mg/dl, HCLF 19.4 ± 2.2 mg/dl; %Diff = 4.9%; p = 0.004), TG/HDL-C Ratio (LCHF 1.1 ± 0.1 mg/dl, HCLF 1.8 ± 0.2 mg/dl; %Diff = 44.4%; p = 0.001) in relation to the HCLF diet. Changes in plasma glucose (LCHF 83.3 ± 4.0 mg/dl, HCLF 88.7 ± 2.4 mg/dl; %Diff = 6.3%; p = 0.107) and HbA1c (LCHF 4.9 ± 0.1%, HCLF 4.9 ± 0.1 %; %Diff = 0.2%; p = 0.821) did not differ between diets. CONCLUSION: Healthy well-trained male distance runners 20-50 years of age demonstrated an exaggerated hypercholesteremic response to a 6-week ad libitum LCHF diet. Despite high TC and LDL-C concentrations, the LCHF diet reduced TG, VLDL, TG/HDL-C Ratio, and increased HDL-C, suggestive of a lower risk of cardiovascular disease. This paradox of hypercholesterolemia in well-trained endurance athletes chronically consuming a LCHF needs to be further investigated to determine whether the blood lipid changes represent an increased or decreased risk of cardiovascular disease.
Effects of a 6-week Low-Carbohydrate High-Fat Diet on Lipid Profiles in Competitive
Recreational Distance Runners
Katie E. Scott1, Philip J. Prins1, Timothy D. Noakes2, Gary L. Welton1, Adam D. Atwell1, Sarah
J. Haley1, Noah J. Esbenshade1, Jacqueline Abraham1, Amy S. Raabe3, Jeffrey D. Buxton1, Dana
L. Ault1. 1Grove City College, Grove City, Pennsylvania, 2The Noakes Foundation, Cape Town,
South Africa, 3Youngstown State University, Youngstown, Ohio.
Low-Carbohydrate High-Fat (LCHF) diets have become very popular among athletes due to
recent research suggesting performance and numerous health benefits. However, few studies
have examined the chronic effects of LCHF diets on the blood lipid profile and other
cardiovascular disease risk factors in athletic populations. PURPOSE: To examine the effect of
a 6-week LCHF diet (69% kcals from fat, 6% carbohydrates), compared to a diet higher in
carbohydrate and lower in fat (HCLF; 56% kcals from carbohydrate, 28% fat) on fasting lipids
triglycerides (TG), LDL-C, HDL-C, total cholesterol (TC), VLDL, TG/HDL-C Ratio, TC/HDL-
C Ratio, glucose and glycated hemoglobin (HbA1c), in competitive recreational distance
runners. METHODS: Seven male athletes (age 35.6 ± 8.4 years, height 178.7 ± 4.1 cm, weight
68.6 ± 1.6 kg; VO2max 61.9 ± 6.1 ml/kg/min) consumed an ad libitum LCHF and ad libitum HCLF
diet in a random order, each for 6 weeks in a crossover design. Plasma lipids where measured on
day 4, 14, 28, and 42 of each diet. RESULTS: The LCHF diet significantly increased TC (mean
± SD; LCHF 197.4 ± 26.3 mg/dl, HCLF 153.4 ± 1.3 mg/dl; %Diff = 25.1%; p = 0.001), LDL-C
(LCHF 108.3 ± 20.6 mg/dl, HCLF 73.5 ± 2.8 mg/dl; %Diff = 38.3%; p = 0.001), HDL-C (LCHF
70.6 ± 3.5 mg/dl, HCLF 60.6 ± 2.1 mg/dl; %Diff = 15.3%; p = 0.015), and decreased TG (LCHF
73.9 ± 4.4 mg/dl, HCLF 97.0 ± 10.9 mg/dl; %Diff = 26.9%; p = 0.005), VLDL (LCHF 18.5 ±
3.5 mg/dl, HCLF 19.4 ± 2.2 mg/dl; %Diff = 4.9%; p = 0.004), TG/HDL-C Ratio (LCHF 1.1 ±
0.1 mg/dl, HCLF 1.8 ± 0.2 mg/dl; %Diff = 44.4%; p = 0.001) in relation to the HCLF diet.
Changes in plasma glucose (LCHF 83.3 ± 4.0 mg/dl, HCLF 88.7 ± 2.4 mg/dl; %Diff = 6.3%; p =
0.107) and HbA1c (LCHF 4.9 ± 0.1%, HCLF 4.9 ± 0.1 %; %Diff = 0.2%; p = 0.821) did not
differ between diets. CONCLUSION: Healthy well-trained male distance runners 20-50 years
of age demonstrated an exaggerated hypercholesteremic response to a 6-week ad libitum LCHF
diet. Despite high TC and LDL-C concentrations, the LCHF diet reduced TG, VLDL, TG/HDL-
C Ratio, and increased HDL-C, suggestive of a lower risk of cardiovascular disease. This
paradox of hypercholesterolemia in well-trained endurance athletes chronically consuming a
LCHF needs to be further investigated to determine whether the blood lipid changes represent an
increased or decreased risk of cardiovascular disease.
Supported by Grove City College Jewell, Moore, & McKenzie Fund
ResearchGate has not been able to resolve any citations for this publication.
ResearchGate has not been able to resolve any references for this publication.