Effect of time restricted feeding with low carbohydrate, high protein and fat diet without calorie restriction on body weight, blood sugar and lipid profile over 6 months: a retrospective cohort study

People with obesity poses a threat for various non-communicable diseases (NCDs). Combining time-restricted feeding (TRF) with calorie restriction has been demonstrated to improve insulin sensitivity, decrease BMI and improved lipid profile. The novel objective of this study is to examine the effects of TRF with low carbohydrate and high protein and fat (LCHPF) diet on control and management of body weight, blood sugar and good cholesterol. This retrospective cohort study was performed at Clinixero in Kuala Lumpur between February 2021 and August 2023. In an open-label trial, all participants were assigned to one of two intervention groups with varying intervention durations (3 months or 6 months). Three month intervention group consists of Phase 1 TRF of 1.5 months (7 weeks) of a 16:8 h fasting-to-feeding ratio followed by another 1.5 months (7 weeks) of a 23:1 h ratio, whereas in six month intervention group phase 1 TRF comprises 3 months (13 weeks) of a 16:8 h fasting-to-feeding ratio followed by another 3 months (13 weeks) of a 23:1 h ratio. Individual BMI was measured along with fasting blood glucose, HbA1c and lipid profile before and after intervention. After a 3-month TRF with LCHPF diet, the mean BMI decreased, although this difference was not statistically significant (p = 0.0572). However, after 6 months BMI was decreased significantly (p < 0.0001). Individual fasting blood sugar (FBS) did not significantly decrease (p = 0.068) after 3 months of intervention. However, it was significantly reduced (p = 0.026) after 6 months of intervention. TRF with LCHPF diet significantly decreased HbA1c after a 3-month (p = 0.019) and 6-month intervention (p < 0.0001). Triglycerides showed a reduction after 3 months of intervention, but it reduced significantly after 6 months (p < 0.001). While the mean cholesterol, HDL and LDL showed a marked increase after 6 months (p < 0.001) of intervention. TRF with LCHPF diet demonstrated significant improvement in BMI, FBS, HbA1c, triglycerides and HDL. Combining TRF and LCHPF could lead to better individual diabetic management.