Oral Presentation ANZOS-ASLM-ICCR 2019

Effect of intermittent fasting versus calorie restriction on sleep, psychological and cognitive function in women with overweight in 8-week randomized controlled trial (#77)

Xiao Tong Teong 1 2 , Amy Hutchison 2 , Bo Liu 1 2 , Gary Wittert 1 2 , Siobhan Banks 3 , Leonie Heilbronn 1 2
  1. Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
  2. Lifelong Health Theme, South Australia Health and Medical Research Institute , Adelaide, South Australia, Australia
  3. Sleep and Chronobiology Laboratory, University of South Australia, Adelaide, South Australia, Australia

Intermittent fasting (IF) is a nutritional intervention that is defined as periods of total fasting or severe calorie restriction (CR) interspersed with periods of ad libitum eating. IF improves metabolic health in both rodent and human studies. This study examined the effects of IF versus CR on cognitive performance measured by Digit Symbol Substitution Task (DSST) and attention measure by Psychomotor Vigilance Task (PVT), as well as perceived sleepiness, hunger, fullness and mood women with overweight or obesity (n=88, 50±1y, BMI 32.3±0.5 kg/m2) after 8-week diet intervention. Participants were randomised to an intermittent 24-hour fasting diet at 70% or 100% of energy requirements (IF70, IF100), versus a group that ate at 70% (CR) or 100% (Control) of energy requirements daily. There was no difference between groups in DSST number correct, or in PVT response error and median response time. There were no between groups effects on feelings of sleepiness measured by Karolinska Sleepiness Scale, or in subjective ratings of mood, hunger and fullness. However, IF100 participants reported feeling more groggy from baseline after the intervention at 12 hour overnight fast (P=0.047) and after 24-hour fast (P=0.028) and IF70 reported feeling that they could eat a large amount of food (P=0.031), decreased feelings of fullness (P=0.016). There were no significant differences between groups in the Positive and Negative Affect Schedule, Depression, Anxiety and Stress Scale, Three Factor Eating Questionnaire and 36-item Short Form Survey (SF-36) or Pittsburgh Sleep Quality Index. Changes in SF-36 general health score and social functioning score from baseline to week 8 (after 24-hour fast) were significantly correlated with percent weight loss (rs=.375, P=0.001; rs=.258, P=0.027, respectively). To our knowledge, this is the first study to determine whether IF affects cognition, sleep and psychological well-being in women who are overweight. Our findings have demonstrated that IF and CR do not negatively affect aspects of sleep quality, psychological and cognitive functioning in women who are overweight.

  1. Hutchison, A.T., et al., Effects of Intermittent Versus Continuous Energy Intakes on Insulin Sensitivity and Metabolic Risk in Women with Overweight. Obesity (Silver Spring), 2019. 27(1): p. 50-58.