Does varying the timing of your fasting window help reduce feelings of hunger?
Intense exercise and structured fasting help against uncontrolled hunger. The timing of your fasting window matters less than the way you fast or exercise.
Intense exercise itself has a clear effect on hunger: immediately after such a workout, participants ate on average 361 kJ less than on a rest day, without making up for it later in the day. Hunger hormones dropped and hormones that suppress appetite rose. This effect occurred regardless of the time of day.
The time at which you exercise makes little difference to hunger. Morning training versus late-afternoon training did not lead to different hunger scores or different energy intake in people with excess weight. Only people without diabetes ate slightly less after a morning workout; in people with diabetes this difference was not found.
Exercising on an empty stomach does increase hunger. People who train on an empty stomach and then eat nothing score up to 23 mm higher on a hundred-point hunger scale than someone who exercises having already eaten. Exercising on an empty stomach followed by a meal still gave 13 mm more hunger. Total energy intake was lowest when exercising on an empty stomach without a subsequent meal, but this came with more hunger and lower energy burn during the effort. Whether that is beneficial in the long run, the studies leave open.
How you structure your fasting day appears to make the most difference. With three full fasting days per week, episodes of uncontrolled eating and binge eating decreased after twelve months. In people who ate a little less every day, those episodes actually increased. No measurable differences in hunger hormones were found in this comparison: leptin, ghrelin (a hormone that stimulates hunger), and similar hormones did not differ between the two groups.
This answer draws on two studies in people and one combined analysis of multiple studies. The combined analysis on exercising on an empty stomach itself notes methodological limitations in the underlying studies, which reduces confidence in those findings. The findings on exercise timing come from a study in people with excess weight, but the timing effects were minimal and only visible in a subgroup. The findings on 4:3 fasting versus daily calorie reduction come from a twelve-month study in people.