Thank you for your comments, support and suggestions @lovemyparrot, @nycnyc2013, @cblasz, @Tracieknits, @fat_teacher - much appreciated.
I don't think I have much to say that I haven't already said before in a post somewhere...
Cblasz makes a valid point about whether I do really want to stop the evening eating. Although ideally I don't want to eat food as a reward (or for comfort) I am not sure if I can change my "need" to do this. I have read books and articles related to this subject and although the suggestions and approaches make sense, I am unable to stick with these longer term. I will have a look at the book you suggest though - it may have some new ideas that will resonate with me.
My "fear" is that I will gradual regain (all) the lost weight, as a result of evening (over)eating. I am already at least several kilos heavier than my lowest weight achieved via 5:2, as judged by how clothes fit. Having said that, I am sure I am still in a healthy weight range, and don't have any health issues that mean I need to lose weight. But I don't want to put on any more...
The advice to "stop worrying about it" is probably exactly what I should do! The main negative for me for having followed the 5:2 "diet" and losing a significant amount of weight - after hardly ever dieting as an adult and certainly rarely stepping on scales - is that I think about eating related issues a lot of the time, which I never did before. I just accepted myself as I was, whatever weight I was, and ate as I pleased without thinking about whether or not I should have any particular food. But I do like being slimmer, as I am now, and do want to stay that way!
I know I don't want to give up any foods and I do still want to eat for the pleasure that a whole range of foods gives me, even though I know that maybe some foods are better not eaten (though I do also believe that moderation does play a part - most healthy people eat foods that "ideally" we shouldn't).
Anyhow... Thanks once again for your thoughts, and best wishes to you all.