Does hunger get worse if you eat fewer calories over a long period of time?
Eating less over a long period raises your hunger hormone, and the more weight you lose, the stronger that effect is. Fasting three days a week appears to spread that pressure slightly better than restricting calories every day.
After prolonged calorie restriction, levels of ghrelin, the hormone that makes you feel hungrier, go up. The more weight is lost, the stronger that rise. This effect has been found across many studies, making it one of the better-supported hormonal responses to weight loss.
At the same time, the hormones that make you feel full, such as PYY and active GLP-1, dip slightly after weight loss from calorie restriction. This was only seen in studies that were less rigorously designed, which makes it less certain. But the combination of more hunger hormone and less fullness hormone does help explain why losing weight is biologically hard to sustain.
Whether you do daily calorie restriction or intermittent fasting makes little difference to your hormone levels: after six and twelve months, ghrelin, leptin, and other hunger-related hormones did not differ between the two approaches. Over the longer term (24 weeks and beyond), feelings of hunger are also comparable between the two methods.
For your eating behaviour, however, it may matter. People who ate less every day for twelve months more often developed binge eating and loss of control around food. Among people who fasted three days a week (and ate freely on the other four), this actually decreased. Daily calorie restriction may therefore put more strain on your relationship with food over time, even though the hormone levels are similar.
This answer draws on four studies, including one large summary combining many studies, both rigorously and less rigorously designed, on hunger hormones during weight loss; two overviews of many studies comparing intermittent fasting with continuous calorie restriction; and one rigorously designed study on 4:3 fasting versus daily restriction over twelve months. The finding on total ghrelin is reasonably well supported; the findings on the active form of ghrelin and on fullness hormones are uncertain because studies give conflicting results or are all of the less rigorous type. The findings on binge eating come from a single rigorously designed study and need confirmation.