Introduction
Alternate day fasting (ADF) is a modified form of calorie
restriction comprising a fast day (25% energy intake for
24 h) alternated with a feed day (ad libitum energy intake
for 24 h) [1]. Previous reports indicate that ADF is an effective strategy to reduce body weight (5% in 12 weeks)
and improve body composition. More recently, it has been
shown that combining ADF with exercise leads to greater
weight loss (7% in 12 weeks) than what has been seen with
ADF or exercise alone [2]. Although these findings are
promising, it is still unclear how this combination therapy
affects eating behaviors, and how these behavioral changes
enhance weight loss. Recent evidence suggests that weight
loss in obese individuals is attributed to an increase in
cognitive restraint [3-5], reduced disinhibition, lower hunger levels [4,5] and decreased consumption of dietary fat
[6]. In view of these findings, key questions that have yet
to be addressed in this field include: Are obese individuals
able to exercise on the fast day? If so, does exercise increase hunger in a way that causes people to cheat on the
fast day? What role does the timing of the exercise session
play in determining whether or not the individual will
cheat? Does ADF, with or without exercise, elicit positive
behavioral changes that may contribute to long-term
steady weight loss?
Therefore, the aim of this study was to examine the behavioral adaptations that occur when ADF is combined
with endurance training, and to investigate how these
changes affect weight loss.