Increase in Calories?

I visited a nutritionist today looking for a meal plan that would result in muscle gain. My new eating plan sees me eat 6 times a day for approx 3500 calories. I have, and continue to train very hard 6 days a week (2 boxing sessions, 3 weight sessions, 1 cardio session, 1 long distance run p/w) and have lost 36kg (80lbs) in the last 12 months. My question is with the introduction of all the new calories (all being clean calories from fruits and vegetables, wholemeal, lean protein, and complex carbohydrates) will I put back on any unwanted fat, i'm so close to having a six-pack and would be devastated if it started turning back to a keg.