Man of Honour
I'm sorry but the crisps , Ice cream, chips (even the sweet potato chips) need to go.. what type of bread do have with your Sandwiches - white or wholewheat?
Don't measure, just be sensible in what you eat replacing high sugar/starch foods with something more natural foods which are slower to release sugars.
This is a good link I found a few weeks, based on the BBC TV program "the truth about carbs"..
https://www.dietdoctor.com/low-carb
If removing them makes a difference it's because they were increasing his calorie intake above maintenance, talking pure weight loss he could be eating just ice cream and as long as he stays below maintenance he'll lose weight.