Are you on fixed doses of insulin then? If so, stick to your carb allowance. But if not, you should be able to up carbs slightly with appropriate bolus adjustment - both amount and timing (ie advance bolusing). Some extra carbs should put the weight on, and as long as you spread them over the day and don't go overboard, your BS should be ok if you manage your insulin appropriately.
Adding some fat might also help eg having full fat milk if you're not already, and adding cheese, nuts, etc
Your food intake sounds quite moderate, so,perhaps you just need to eat a little more and you'll be ok
If unsure, check with your DSN as always.