Keep Track of How Much You Eat
Many people do gain weight, and the reasons are complex. One factor is that you are no longer losing large quantities of calories in your urine in the form of glucose.
You will need to eliminate calories from your diet equal to what was being lost in your urine. You won't know how many calories this is unless you closely monitor your weight and what you eat.
If you start to gain weight, reduce the amount of food you eat and exercise more. If lowering your blood sugar causes you to have more low blood-sugar reactions, then the food that you eat to treat the reactions may add to weight gain.