I wouldn't worry about your brother, wait until he sees your results. You are down quite a bit already, and it will show. Like Old said, you can explain that all your vitamins and nutrients are already incorporated in to the meals you eat so it is a Healthy plan.
I saw one of my son's today that hasn't seen me in a few months and he just couldn't believe how I look. He said, What ever your doing, It's working. Keep doing it. He was amazed at how much my face has changed. I haven't been this weight in 20 years and he just isn't used to seeing me like this.
You can also tell your brother that you are on a specialized eating program before you go to visit him to set his expectations and tell him a little about it. He can look it up online himself if he cares, the successes are amazing. Tell him about Dr Anderson and his Take shape for Life program. You are not just getting, you are getting Healthy.
Relax and just have fun, but don't lose sight of your goal.
I am the Gram!