The effects of different intermittent fasting practices on nutritional status and diet quality

This study was planned to investigate the effects of time-restricted feeding, Ramadan fasting and energy-restricted diet on the nutritional status and diet quality of individuals, and to compare the effects of time-restricted feeding and energy-restricted diet. The study was planned and conducted as a case-control study and an 8-week intervention on 36 female individuals (10 individuals in the time-restricted feeding group, 13 individuals in the Ramadan fasting group and 13 individuals in the energy-restricted diet group) aged 19-50, overweight and without any chronic disease. Socio-demographic characteristics, physical activity status, circadian rhythm characteristics, sleep quality, food consumption and diet quality of individuals were questioned through the questionnaire form. Anthropometric measurements, body compositions, blood pressure and heart rates, resting energy expenditure (REE) and daily step numbers of individuals were evaluated and some biochemical parameters were analyzed. All individuals maintained their physical activity levels throughout the study. A decrease of 3.2%, 5.5%, and 1.1% was found in the body weights of individuals in the time-restricted feeding, energy-restricted diet, and Ramadan fasting groups, respectively (p<0.05). While no significant change was observed in the body fat percentage values of the individuals in the time-restricted diet group (p>0.05), a 7.1% decrease was observed in the energy-restricted diet group (p<0.05). While there was a statistically significant decrease was found in total cholesterol value in the energy-restricted diet group; in total cholesterol and low-density lipoprotein cholesterol (LDL-C) values in the time-restricted feeding group; in C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-alpha) values in the Ramadan fasting group, a statistically significant increase was found in adiponectin and total antioxidant status (TAS) values in the energy-restricted diet group; in TNF-alpha value in the time-restricted feeding group (p<0.05). No significant change was observed in REE, total energy expenditure (TEE), sleep quality, blood pressure and heart rate of individuals in all three groups during the study (p>0.05). The daily energy intakes of individuals in the time-restricted feeding, energy-restricted diet, and Ramadan fasting groups were decreased 405.7 kcal (18.5%), 954.2 kcal (42.2%) and 408.6 kcal (23.0%), respectively. While no change was observed in the diet quality of the individuals in the time-restricted feeding and Ramadan fasting groups (p>0.05), a significant increase was found in the diet quality scores of the individuals in the energy-restricted diet group (p<0.05). As a result, in this study, a positive effect of Ramadan fasting on body weight and composition and inflammatory markers was found. Time-restricted feeding has been found to have a positive effect on body weight and blood cholesterol levels. An energy-restricted diet has been shown to be superior to a time-restricted feeding in weight loss and improvement of body composition. Of the three dietary approaches, only the energy-restricted diet has been found to have a positive effect on the diet quality of individuals. All three dietary approaches can be effective on obesity and related complications.