Then we started working the same schedule, breakfast together. The whole thing unravelled with a casual comment he made. "Wow, you're really stingy with the sugar in your coffee."
Except I wasn't. I was actually indulging myself, like two tablespoons.
Show me how you make coffee? Ah. Yes. If you put 500 calories of sugar and cream into your coffee multiple times a day, you're not gonna lose weight.
He didn't believe me at first! I had to measure his quantities out and calculate it and show him. Liquids/powders in general seem to trip people up. We are bad at measuring them by sight. Soda, mayonnaise and dips. The oil in a nice salad dressing applied over-liberally can exceed the calories in the burger that goes with it.
Try measuring/weighing these sorts of foods and looking up their caloric content if you haven't before. You may be a shocked as my poor roommate was.