I usually bring make myself one sandwich for a packed lunch at work everyday so I went ahead and made myself a list of 'naughties' for the days where I feel I need something extra: (This isn't all the list btw as you said you only wanted chocolate)
Chocolate Snack-a-jack 62 cal
Alpen Light Chocolate And Fudge Bar 63 cal
Weetabix White Chocolate Oaty Bar 67 cal
Milkyway Magic Stars Funsize 67 cal
[FONT="]Milky Way Funsize 70 cal
Mcvitie Go Ahead Forest Fruits Yoghurt 72 cal
Weight Watchers Caramel Wafer 78 cal
Weetabix Milk Chocolate Oaty Bars 79 cal
Weetabix Oaty Bars Toffee 80 cal
Kelkin Chocolate Covered Rice Cakes 83 cal
Weight Watchers Eclairs 83 cal
Kellogg's R/Sqr Krispie B/Size Marshmallow 85 cal
Weight Watchers Mini Chocolate Muffin 85 cal[/FONT][FONT="]
[/FONT][FONT="]Burtons Mini Jammie Dodgers 88 cal
Tesco Value Jam And Vanilla Mini Roll 90 cal
[/FONT][FONT="]Twix Funsize 98 cal
Drifter Single 99 cal[/FONT]
[FONT="]Toffee Crisp funsize 99 cal
Maltesers Funsize 99 cal[/FONT]
[FONT="]Kit Kat 2 Finger 107 cal
Cadbury Fair Trade Dairy Milk For Kids 110 cal
Cadburys Curly Wurly 115 cal
Cadburys Fudge 115 cal
[/FONT][FONT="]Burtons Jammie Wagon Wheels 161 cal
Although I tend to stick to fruit/sugar free jelly/air popped popcorn*/rice cake for a lunchtime treat.
I also see that Options has been mentioned, must say that is the best Hot Chocolate I have ever tasted, that goes for all the flavours!
*1 cup of air popped popcorn with Walden Farm Chocolate Syrup

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