Effects of a Low-Carbohydrate High-Fat Diet Combined with High-Intensity Interval Training on Body Composition and Maximal Oxygen Uptake: A Systematic Review and Meta-Analysis.

Jing Hu,Zhen Wang,Junping Li,Bingkai Lei,Ruiyuan Wang

doi:10.3390/ijerph182010740

Abstract

The low-carbohydrate high-fat (LCHF) diet has recently been subject to attention on account of its reported influences on body composition and physical performance. However, the combined effect of LCHF with high-intensity interval training (HIIT) is unclear. A systematic review and meta-analysis were conducted to explore the effect of the LCHF diet combined with HIIT on human body composition (i.e., body weight (BM), body mass index (BMI), fat mass (FM), body fat percentage (BFP), fat-free mass (FFM)) and maximal oxygen uptake (VO2max). Online libraries (PubMed, Web of Science, EMBASE, Cochrane Library, EBSCO, CNKI, Wan Fang) were used to search initial studies until July 2021, from which 10 out of 2440 studies were included. WMD served as the effect size with a confidence interval value of 95%. The results of meta-analysis showed a significant reduction in BM (WMD = −5.299; 95% CI: −7.223, −3.376, p = 0.000), BMI (WMD = −1.150; 95% CI: −2.225, −0.075, p = 0.036), BFP (WMD = −2.787; 95% CI: −4.738, −0.835, p = 0.005) and a significant increase in VO2max (WMD = 3.311; 95% CI: 1.705, 4.918, p = 0.000), while FM (WMD = −2.221; 95% CI: −4.582, 0.139, p = 0.065) and FFM (WMD = 0.487; 95% CI: −3.512, 4.469, p = 0.814) remained unchanged. In conclusion, the LCHF diet combined with HIIT can reduce weight and fat effectively. This combination is sufficient to prevent muscle mass loss during LCHF, and further enhance VO2max. Further research might be required to clarify the effect of other types of exercise on body composition and physical performance during LCHF.

Highlights

Body composition is influenced by nutritional and physical activity intervention.The low-carbohydrate high-fat (LCHF) diet is a re-emerged dietary approach, which is characterized by decreased carbohydrate intake and high levels of fat consumption with adequate protein provided [1]
The results of meta-analysis indicate that participants that adhered to the LCHF diet and high-intensity interval training (HIIT) showed a significant reduction in body mass (BM) (WMD = −5.299; 95% CI: −7.223, −3.376, p = 0.000, Figure 4), BMI (WMD = −1.150; 95% CI: −2.225, –0.075, p = 0.036, Figure 5), and body fat percentage (BFP) (WMD = −2.787; 95% CI: −4.738, −0.835, p = 0.005, Figure 6), and a significant increase in VO2max (WMD = 3.311; 95% CI: 1.705, 4.918, p = 0.000, Figure 7) as compared to the control group, while fat mass (FM) (WMD = −2.221; 95% CI: −4.582, 0.139, p = 0.065, Figure 8)
Our result reveals that LCHF combined with HIIT has no significant effect on fat free mass (FFM), which implies that HIIT prevents greater muscle mass loss during LCHF than RT

Summary

Introduction

Body composition is influenced by nutritional and physical activity intervention.The low-carbohydrate high-fat (LCHF) diet is a re-emerged dietary approach, which is characterized by decreased carbohydrate intake (approximately 50 g/d) and high levels of fat consumption with adequate protein provided [1]. LCHF has become fashionable because of its potential to induce rapid weight loss, including ketogenic diets (KDs), the Zone diet, the South Beach diet, the Atkins diet, and other carbohydraterestricted diets (CRD) [5,6]. The purpose of this low-carb, high-fat dietary strategy of LCHF is to increase the utilization of fat as muscle fuel and to keep the body at high levels of circulating ketones for weight loss [7,8]. Some studies revealed that individuals who consumed the LCHF diet experienced greater body weight (BM) and fat mass (FM)

Results

Discussion

Conclusion